[PATCH 00/12] Convert btree locking to an rwsem #13

josefbacik · 2020-08-20T15:46:43Z

Link to patches

https://lore.kernel.org/linux-btrfs/[email protected]/

The cited commit holds encap tbl lock unconditionally when setting up dests. But it may cause the following deadlock: PID: 1063722 TASK: ffffa062ca5d0000 CPU: 13 COMMAND: "handler8" #0 [ffffb14de05b7368] __schedule at ffffffffa1d5aa91 #1 [ffffb14de05b7410] schedule at ffffffffa1d5afdb #2 [ffffb14de05b7430] schedule_preempt_disabled at ffffffffa1d5b528 #3 [ffffb14de05b7440] __mutex_lock at ffffffffa1d5d6cb #4 [ffffb14de05b74e8] mutex_lock_nested at ffffffffa1d5ddeb #5 [ffffb14de05b74f8] mlx5e_tc_tun_encap_dests_set at ffffffffc12f2096 [mlx5_core] #6 [ffffb14de05b7568] post_process_attr at ffffffffc12d9fc5 [mlx5_core] #7 [ffffb14de05b75a0] mlx5e_tc_add_fdb_flow at ffffffffc12de877 [mlx5_core] torvalds#8 [ffffb14de05b75f0] __mlx5e_add_fdb_flow at ffffffffc12e0eef [mlx5_core] torvalds#9 [ffffb14de05b7660] mlx5e_tc_add_flow at ffffffffc12e12f7 [mlx5_core] torvalds#10 [ffffb14de05b76b8] mlx5e_configure_flower at ffffffffc12e1686 [mlx5_core] torvalds#11 [ffffb14de05b7720] mlx5e_rep_indr_offload at ffffffffc12e3817 [mlx5_core] #12 [ffffb14de05b7730] mlx5e_rep_indr_setup_tc_cb at ffffffffc12e388a [mlx5_core] #13 [ffffb14de05b7740] tc_setup_cb_add at ffffffffa1ab2ba8 torvalds#14 [ffffb14de05b77a0] fl_hw_replace_filter at ffffffffc0bdec2f [cls_flower] #15 [ffffb14de05b7868] fl_change at ffffffffc0be6caa [cls_flower] #16 [ffffb14de05b7908] tc_new_tfilter at ffffffffa1ab71f0 [1031218.028143] wait_for_completion+0x24/0x30 [1031218.028589] mlx5e_update_route_decap_flows+0x9a/0x1e0 [mlx5_core] [1031218.029256] mlx5e_tc_fib_event_work+0x1ad/0x300 [mlx5_core] [1031218.029885] process_one_work+0x24e/0x510 Actually no need to hold encap tbl lock if there is no encap action. Fix it by checking if encap action exists or not before holding encap tbl lock. Fixes: 37c3b9f ("net/mlx5e: Prevent encap offload when neigh update is running") Signed-off-by: Chris Mi <[email protected]> Reviewed-by: Vlad Buslov <[email protected]> Signed-off-by: Saeed Mahameed <[email protected]>

Noticed with: make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin Direct leak of 45 byte(s) in 1 object(s) allocated from: #0 0x7f213f87243b in strdup (/lib64/libasan.so.8+0x7243b) #1 0x63d15f in evsel__set_filter util/evsel.c:1371 #2 0x63d15f in evsel__append_filter util/evsel.c:1387 #3 0x63d15f in evsel__append_tp_filter util/evsel.c:1400 #4 0x62cd52 in evlist__append_tp_filter util/evlist.c:1145 #5 0x62cd52 in evlist__append_tp_filter_pids util/evlist.c:1196 #6 0x541e49 in trace__set_filter_loop_pids /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3646 #7 0x541e49 in trace__set_filter_pids /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3670 torvalds#8 0x541e49 in trace__run /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3970 torvalds#9 0x541e49 in cmd_trace /home/acme/git/perf-tools/tools/perf/builtin-trace.c:5141 torvalds#10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools/tools/perf/perf.c:323 torvalds#11 0x4196da in handle_internal_command /home/acme/git/perf-tools/tools/perf/perf.c:377 #12 0x4196da in run_argv /home/acme/git/perf-tools/tools/perf/perf.c:421 #13 0x4196da in main /home/acme/git/perf-tools/tools/perf/perf.c:537 torvalds#14 0x7f213e84a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) Free it on evsel__exit(). Acked-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Link: https://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

To plug these leaks detected with: $ make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin ================================================================= ==473890==ERROR: LeakSanitizer: detected memory leaks Direct leak of 112 byte(s) in 1 object(s) allocated from: #0 0x7fdf19aba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x987836 in zalloc (/home/acme/bin/perf+0x987836) #2 0x5367ae in thread_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1289 #3 0x5367ae in thread__trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1307 #4 0x5367ae in trace__sys_exit /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:2468 #5 0x52bf34 in trace__handle_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3177 #6 0x52bf34 in __trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3685 #7 0x542927 in trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3712 torvalds#8 0x542927 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:4055 torvalds#9 0x542927 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5141 torvalds#10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 torvalds#11 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 #12 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 #13 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 torvalds#14 0x7fdf18a4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) Direct leak of 2048 byte(s) in 1 object(s) allocated from: #0 0x7f788fcba6af in __interceptor_malloc (/lib64/libasan.so.8+0xba6af) #1 0x5337c0 in trace__sys_enter /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:2342 #2 0x52bfb4 in trace__handle_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3191 #3 0x52bfb4 in __trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3699 #4 0x542883 in trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3726 #5 0x542883 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:4069 #6 0x542883 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5155 #7 0x5ef232 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 torvalds#8 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 torvalds#9 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 torvalds#10 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 torvalds#11 0x7f788ec4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) Indirect leak of 48 byte(s) in 1 object(s) allocated from: #0 0x7fdf19aba6af in __interceptor_malloc (/lib64/libasan.so.8+0xba6af) #1 0x77b335 in intlist__new util/intlist.c:116 #2 0x5367fd in thread_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1293 #3 0x5367fd in thread__trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:1307 #4 0x5367fd in trace__sys_exit /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:2468 #5 0x52bf34 in trace__handle_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3177 #6 0x52bf34 in __trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3685 #7 0x542927 in trace__deliver_event /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3712 torvalds#8 0x542927 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:4055 torvalds#9 0x542927 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5141 torvalds#10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 torvalds#11 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 #12 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 #13 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 torvalds#14 0x7fdf18a4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) Acked-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Link: https://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

In 3cb4d5e ("perf trace: Free syscall tp fields in evsel->priv") it only was freeing if strcmp(evsel->tp_format->system, "syscalls") returned zero, while the corresponding initialization of evsel->priv was being performed if it was _not_ zero, i.e. if the tp system wasn't 'syscalls'. Just stop looking for that and free it if evsel->priv was set, which should be equivalent. Also use the pre-existing evsel_trace__delete() function. This resolves these leaks, detected with: $ make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin ================================================================= ==481565==ERROR: LeakSanitizer: detected memory leaks Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966) #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307 #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333 #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458 #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480 #6 0x540e8b in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3212 #7 0x540e8b in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891 torvalds#8 0x540e8b in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156 torvalds#9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 torvalds#10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 torvalds#11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 #12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 #13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) Direct leak of 40 byte(s) in 1 object(s) allocated from: #0 0x7f7343cba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x987966 in zalloc (/home/acme/bin/perf+0x987966) #2 0x52f9b9 in evsel_trace__new /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:307 #3 0x52f9b9 in evsel__syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:333 #4 0x52f9b9 in evsel__init_raw_syscall_tp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:458 #5 0x52f9b9 in perf_evsel__raw_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:480 #6 0x540dd1 in trace__add_syscall_newtp /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3205 #7 0x540dd1 in trace__run /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:3891 torvalds#8 0x540dd1 in cmd_trace /home/acme/git/perf-tools-next/tools/perf/builtin-trace.c:5156 torvalds#9 0x5ef262 in run_builtin /home/acme/git/perf-tools-next/tools/perf/perf.c:323 torvalds#10 0x4196da in handle_internal_command /home/acme/git/perf-tools-next/tools/perf/perf.c:377 torvalds#11 0x4196da in run_argv /home/acme/git/perf-tools-next/tools/perf/perf.c:421 #12 0x4196da in main /home/acme/git/perf-tools-next/tools/perf/perf.c:537 #13 0x7f7342c4a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f) SUMMARY: AddressSanitizer: 80 byte(s) leaked in 2 allocation(s). [root@quaco ~]# With this we plug all leaks with "perf trace sleep 1". Fixes: 3cb4d5e ("perf trace: Free syscall tp fields in evsel->priv") Acked-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Riccardo Mancini <[email protected]> Link: https://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

…failure to add a probe Building perf with EXTRA_CFLAGS="-fsanitize=address" a leak is detect when trying to add a probe to a non-existent function: # perf probe -x ~/bin/perf dso__neW Probe point 'dso__neW' not found. Error: Failed to add events. ================================================================= ==296634==ERROR: LeakSanitizer: detected memory leaks Direct leak of 128 byte(s) in 1 object(s) allocated from: #0 0x7f67642ba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x7f67641a76f1 in allocate_cfi (/lib64/libdw.so.1+0x3f6f1) Direct leak of 65 byte(s) in 1 object(s) allocated from: #0 0x7f67642b95b5 in __interceptor_realloc.part.0 (/lib64/libasan.so.8+0xb95b5) #1 0x6cac75 in strbuf_grow util/strbuf.c:64 #2 0x6ca934 in strbuf_init util/strbuf.c:25 #3 0x9337d2 in synthesize_perf_probe_point util/probe-event.c:2018 #4 0x92be51 in try_to_find_probe_trace_events util/probe-event.c:964 #5 0x93d5c6 in convert_to_probe_trace_events util/probe-event.c:3512 #6 0x93d6d5 in convert_perf_probe_events util/probe-event.c:3529 #7 0x56f37f in perf_add_probe_events /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:354 torvalds#8 0x572fbc in __cmd_probe /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:738 torvalds#9 0x5730f2 in cmd_probe /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:766 torvalds#10 0x635d81 in run_builtin /var/home/acme/git/perf-tools-next/tools/perf/perf.c:323 torvalds#11 0x6362c1 in handle_internal_command /var/home/acme/git/perf-tools-next/tools/perf/perf.c:377 #12 0x63667a in run_argv /var/home/acme/git/perf-tools-next/tools/perf/perf.c:421 #13 0x636b8d in main /var/home/acme/git/perf-tools-next/tools/perf/perf.c:537 torvalds#14 0x7f676302950f in __libc_start_call_main (/lib64/libc.so.6+0x2950f) SUMMARY: AddressSanitizer: 193 byte(s) leaked in 2 allocation(s). # synthesize_perf_probe_point() returns a "detachec" strbuf, i.e. a malloc'ed string that needs to be free'd. An audit will be performed to find other such cases. Acked-by: Masami Hiramatsu <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Link: https://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

With latest clang18, I hit test_progs failures for the following test: #13/2 bpf_cookie/multi_kprobe_link_api:FAIL #13/3 bpf_cookie/multi_kprobe_attach_api:FAIL #13 bpf_cookie:FAIL #75 fentry_fexit:FAIL #76/1 fentry_test/fentry:FAIL #76 fentry_test:FAIL #80/1 fexit_test/fexit:FAIL #80 fexit_test:FAIL #110/1 kprobe_multi_test/skel_api:FAIL #110/2 kprobe_multi_test/link_api_addrs:FAIL #110/3 kprobe_multi_test/link_api_syms:FAIL #110/4 kprobe_multi_test/attach_api_pattern:FAIL #110/5 kprobe_multi_test/attach_api_addrs:FAIL #110/6 kprobe_multi_test/attach_api_syms:FAIL #110 kprobe_multi_test:FAIL For example, for #13/2, the error messages are: [...] kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1 [...] kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1 clang17 does not have this issue. Further investigation shows that kernel func bpf_fentry_test7(), used in the above tests, is inlined by the compiler although it is marked as noinline. int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg) { return (long)arg; } It is known that for simple functions like the above (e.g. just returning a constant or an input argument), the clang compiler may still do inlining for a noinline function. Adding 'asm volatile ("")' in the beginning of the bpf_fentry_test7() can prevent inlining. Signed-off-by: Yonghong Song <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Tested-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]

The following processes run into a deadlock. CPU 41 was waiting for CPU 29 to handle a CSD request while holding spinlock "crashdump_lock", but CPU 29 was hung by that spinlock with IRQs disabled. PID: 17360 TASK: ffff95c1090c5c40 CPU: 41 COMMAND: "mrdiagd" !# 0 [ffffb80edbf37b58] __read_once_size at ffffffff9b871a40 include/linux/compiler.h:185:0 !# 1 [ffffb80edbf37b58] atomic_read at ffffffff9b871a40 arch/x86/include/asm/atomic.h:27:0 !# 2 [ffffb80edbf37b58] dump_stack at ffffffff9b871a40 lib/dump_stack.c:54:0 # 3 [ffffb80edbf37b78] csd_lock_wait_toolong at ffffffff9b131ad5 kernel/smp.c:364:0 # 4 [ffffb80edbf37b78] __csd_lock_wait at ffffffff9b131ad5 kernel/smp.c:384:0 # 5 [ffffb80edbf37bf8] csd_lock_wait at ffffffff9b13267a kernel/smp.c:394:0 # 6 [ffffb80edbf37bf8] smp_call_function_many at ffffffff9b13267a kernel/smp.c:843:0 # 7 [ffffb80edbf37c50] smp_call_function at ffffffff9b13279d kernel/smp.c:867:0 # 8 [ffffb80edbf37c50] on_each_cpu at ffffffff9b13279d kernel/smp.c:976:0 # 9 [ffffb80edbf37c78] flush_tlb_kernel_range at ffffffff9b085c4b arch/x86/mm/tlb.c:742:0 torvalds#10 [ffffb80edbf37cb8] __purge_vmap_area_lazy at ffffffff9b23a1e0 mm/vmalloc.c:701:0 torvalds#11 [ffffb80edbf37ce0] try_purge_vmap_area_lazy at ffffffff9b23a2cc mm/vmalloc.c:722:0 #12 [ffffb80edbf37ce0] free_vmap_area_noflush at ffffffff9b23a2cc mm/vmalloc.c:754:0 #13 [ffffb80edbf37cf8] free_unmap_vmap_area at ffffffff9b23bb3b mm/vmalloc.c:764:0 torvalds#14 [ffffb80edbf37cf8] remove_vm_area at ffffffff9b23bb3b mm/vmalloc.c:1509:0 #15 [ffffb80edbf37d18] __vunmap at ffffffff9b23bb8a mm/vmalloc.c:1537:0 #16 [ffffb80edbf37d40] vfree at ffffffff9b23bc85 mm/vmalloc.c:1612:0 #17 [ffffb80edbf37d58] megasas_free_host_crash_buffer [megaraid_sas] at ffffffffc020b7f2 drivers/scsi/megaraid/megaraid_sas_fusion.c:3932:0 #18 [ffffb80edbf37d80] fw_crash_state_store [megaraid_sas] at ffffffffc01f804d drivers/scsi/megaraid/megaraid_sas_base.c:3291:0 #19 [ffffb80edbf37dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0 #20 [ffffb80edbf37dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0 #21 [ffffb80edbf37de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0 #22 [ffffb80edbf37e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0 #23 [ffffb80edbf37ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0 #24 [ffffb80edbf37ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0 #25 [ffffb80edbf37ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0 #26 [ffffb80edbf37f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0 #27 [ffffb80edbf37f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0 PID: 17355 TASK: ffff95c1090c3d80 CPU: 29 COMMAND: "mrdiagd" !# 0 [ffffb80f2d3c7d30] __read_once_size at ffffffff9b0f2ab0 include/linux/compiler.h:185:0 !# 1 [ffffb80f2d3c7d30] native_queued_spin_lock_slowpath at ffffffff9b0f2ab0 kernel/locking/qspinlock.c:368:0 # 2 [ffffb80f2d3c7d58] pv_queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/paravirt.h:674:0 # 3 [ffffb80f2d3c7d58] queued_spin_lock_slowpath at ffffffff9b0f244b arch/x86/include/asm/qspinlock.h:53:0 # 4 [ffffb80f2d3c7d68] queued_spin_lock at ffffffff9b8961a6 include/asm-generic/qspinlock.h:90:0 # 5 [ffffb80f2d3c7d68] do_raw_spin_lock_flags at ffffffff9b8961a6 include/linux/spinlock.h:173:0 # 6 [ffffb80f2d3c7d68] __raw_spin_lock_irqsave at ffffffff9b8961a6 include/linux/spinlock_api_smp.h:122:0 # 7 [ffffb80f2d3c7d68] _raw_spin_lock_irqsave at ffffffff9b8961a6 kernel/locking/spinlock.c:160:0 # 8 [ffffb80f2d3c7d88] fw_crash_buffer_store [megaraid_sas] at ffffffffc01f8129 drivers/scsi/megaraid/megaraid_sas_base.c:3205:0 # 9 [ffffb80f2d3c7dc0] dev_attr_store at ffffffff9b56dd7b drivers/base/core.c:758:0 torvalds#10 [ffffb80f2d3c7dd0] sysfs_kf_write at ffffffff9b326acf fs/sysfs/file.c:144:0 torvalds#11 [ffffb80f2d3c7de0] kernfs_fop_write at ffffffff9b325fd4 fs/kernfs/file.c:316:0 #12 [ffffb80f2d3c7e20] __vfs_write at ffffffff9b29418a fs/read_write.c:480:0 #13 [ffffb80f2d3c7ea8] vfs_write at ffffffff9b294462 fs/read_write.c:544:0 torvalds#14 [ffffb80f2d3c7ee8] SYSC_write at ffffffff9b2946ec fs/read_write.c:590:0 #15 [ffffb80f2d3c7ee8] SyS_write at ffffffff9b2946ec fs/read_write.c:582:0 #16 [ffffb80f2d3c7f30] do_syscall_64 at ffffffff9b003ca9 arch/x86/entry/common.c:298:0 #17 [ffffb80f2d3c7f58] entry_SYSCALL_64 at ffffffff9ba001b1 arch/x86/entry/entry_64.S:238:0 The lock is used to synchronize different sysfs operations, it doesn't protect any resource that will be touched by an interrupt. Consequently it's not required to disable IRQs. Replace the spinlock with a mutex to fix the deadlock. Signed-off-by: Junxiao Bi <[email protected]> Link: https://lore.kernel.org/r/[email protected] Reviewed-by: Mike Christie <[email protected]> Cc: [email protected] Signed-off-by: Martin K. Petersen <[email protected]>

Currently when rmdir on an instance is done, eventfs_remove_events_dir() is called and it does a dput on the dentry and then frees the eventfs_inode that represents the events directory. But there's no protection against a reader reading the top level events directory at the same time and we can get a use after free error. Instead, use the dput() associated to the dentry to also free the eventfs_inode associated to the events directory, as that will get called when the last reference to the directory is released. This issue triggered the following KASAN report: ================================================================== BUG: KASAN: slab-use-after-free in eventfs_root_lookup+0x88/0x1b0 Read of size 8 at addr ffff888120130ca0 by task ftracetest/1201 CPU: 4 PID: 1201 Comm: ftracetest Not tainted 6.5.0-test-10737-g469e0a8194e7 #13 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x90 print_report+0xcf/0x670 ? __pfx_ring_buffer_record_off+0x10/0x10 ? _raw_spin_lock_irqsave+0x2b/0x70 ? __virt_addr_valid+0xd9/0x160 kasan_report+0xd4/0x110 ? eventfs_root_lookup+0x88/0x1b0 ? eventfs_root_lookup+0x88/0x1b0 eventfs_root_lookup+0x88/0x1b0 ? eventfs_root_lookup+0x33/0x1b0 __lookup_slow+0x194/0x2a0 ? __pfx___lookup_slow+0x10/0x10 ? down_read+0x11c/0x330 walk_component+0x166/0x220 link_path_walk.part.0.constprop.0+0x3a3/0x5a0 ? seqcount_lockdep_reader_access+0x82/0x90 ? __pfx_link_path_walk.part.0.constprop.0+0x10/0x10 path_openat+0x143/0x11f0 ? __lock_acquire+0xa1a/0x3220 ? __pfx_path_openat+0x10/0x10 ? __pfx___lock_acquire+0x10/0x10 do_filp_open+0x166/0x290 ? __pfx_do_filp_open+0x10/0x10 ? lock_is_held_type+0xce/0x120 ? preempt_count_sub+0xb7/0x100 ? _raw_spin_unlock+0x29/0x50 ? alloc_fd+0x1a0/0x320 do_sys_openat2+0x126/0x160 ? rcu_is_watching+0x34/0x60 ? __pfx_do_sys_openat2+0x10/0x10 ? __might_resched+0x2cf/0x3b0 ? __fget_light+0xdf/0x100 __x64_sys_openat+0xcd/0x140 ? __pfx___x64_sys_openat+0x10/0x10 ? syscall_enter_from_user_mode+0x22/0x90 ? lockdep_hardirqs_on+0x7d/0x100 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f1dceef5e51 Code: 75 57 89 f0 25 00 00 41 00 3d 00 00 41 00 74 49 80 3d 9a 27 0e 00 00 74 6d 89 da 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 93 00 00 00 48 8b 54 24 28 64 48 2b 14 25 RSP: 002b:00007fff2cddf380 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000241 RCX: 00007f1dceef5e51 RDX: 0000000000000241 RSI: 000055d7520677d0 RDI: 00000000ffffff9c RBP: 000055d7520677d0 R08: 000000000000001e R09: 0000000000000001 R10: 00000000000001b6 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000003 R14: 000055d752035678 R15: 000055d752067788 </TASK> Allocated by task 1200: kasan_save_stack+0x2f/0x50 kasan_set_track+0x21/0x30 __kasan_kmalloc+0x8b/0x90 eventfs_create_events_dir+0x54/0x220 create_event_toplevel_files+0x42/0x130 event_trace_add_tracer+0x33/0x180 trace_array_create_dir+0x52/0xf0 trace_array_create+0x361/0x410 instance_mkdir+0x6b/0xb0 tracefs_syscall_mkdir+0x57/0x80 vfs_mkdir+0x275/0x380 do_mkdirat+0x1da/0x210 __x64_sys_mkdir+0x74/0xa0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Freed by task 1251: kasan_save_stack+0x2f/0x50 kasan_set_track+0x21/0x30 kasan_save_free_info+0x27/0x40 __kasan_slab_free+0x106/0x180 __kmem_cache_free+0x149/0x2e0 event_trace_del_tracer+0xcb/0x120 __remove_instance+0x16a/0x340 instance_rmdir+0x77/0xa0 tracefs_syscall_rmdir+0x77/0xc0 vfs_rmdir+0xed/0x2d0 do_rmdir+0x235/0x280 __x64_sys_rmdir+0x5f/0x90 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 The buggy address belongs to the object at ffff888120130ca0 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of freed 16-byte region [ffff888120130ca0, ffff888120130cb0) The buggy address belongs to the physical page: page:000000004dbddbb0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x120130 flags: 0x17ffffc0000800(slab|node=0|zone=2|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 0017ffffc0000800 ffff8881000423c0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000800080 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888120130b80: 00 00 fc fc 00 05 fc fc 00 00 fc fc 00 02 fc fc ffff888120130c00: 00 07 fc fc 00 00 fc fc 00 00 fc fc fa fb fc fc >ffff888120130c80: 00 00 fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc ^ ffff888120130d00: 00 00 fc fc 00 00 fc fc 00 00 fc fc fa fb fc fc ffff888120130d80: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ================================================================== Link: https://lkml.kernel.org/r/[email protected] Link: https://lore.kernel.org/all/[email protected]/ Cc: Ajay Kaher <[email protected]> Cc: Masami Hiramatsu <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Andrew Morton <[email protected]> Fixes: 5bdcd5f eventfs: ("Implement removal of meta data from eventfs") Tested-by: Linux Kernel Functional Testing <[email protected]> Tested-by: Naresh Kamboju <[email protected]> Reported-by: Zheng Yejian <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]>

Fix an error detected by memory sanitizer: ``` ==4033==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x55fb0fbedfc7 in read_alias_info tools/perf/util/pmu.c:457:6 #1 0x55fb0fbea339 in check_info_data tools/perf/util/pmu.c:1434:2 #2 0x55fb0fbea339 in perf_pmu__check_alias tools/perf/util/pmu.c:1504:9 #3 0x55fb0fbdca85 in parse_events_add_pmu tools/perf/util/parse-events.c:1429:32 #4 0x55fb0f965230 in parse_events_parse tools/perf/util/parse-events.y:299:6 #5 0x55fb0fbdf6b2 in parse_events__scanner tools/perf/util/parse-events.c:1822:8 #6 0x55fb0fbdf8c1 in __parse_events tools/perf/util/parse-events.c:2094:8 #7 0x55fb0fa8ffa9 in parse_events tools/perf/util/parse-events.h:41:9 torvalds#8 0x55fb0fa8ffa9 in test_event tools/perf/tests/parse-events.c:2393:8 torvalds#9 0x55fb0fa8f458 in test__pmu_events tools/perf/tests/parse-events.c:2551:15 torvalds#10 0x55fb0fa6d93f in run_test tools/perf/tests/builtin-test.c:242:9 torvalds#11 0x55fb0fa6d93f in test_and_print tools/perf/tests/builtin-test.c:271:8 #12 0x55fb0fa6d082 in __cmd_test tools/perf/tests/builtin-test.c:442:5 #13 0x55fb0fa6d082 in cmd_test tools/perf/tests/builtin-test.c:564:9 torvalds#14 0x55fb0f942720 in run_builtin tools/perf/perf.c:322:11 #15 0x55fb0f942486 in handle_internal_command tools/perf/perf.c:375:8 #16 0x55fb0f941dab in run_argv tools/perf/perf.c:419:2 #17 0x55fb0f941dab in main tools/perf/perf.c:535:3 ``` Fixes: 7b723db ("perf pmu: Be lazy about loading event info files from sysfs") Signed-off-by: Ian Rogers <[email protected]> Cc: James Clark <[email protected]> Cc: Kan Liang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Namhyung Kim <[email protected]>

vhost_worker will call tun call backs to receive packets. If too many illegal packets arrives, tun_do_read will keep dumping packet contents. When console is enabled, it will costs much more cpu time to dump packet and soft lockup will be detected. net_ratelimit mechanism can be used to limit the dumping rate. PID: 33036 TASK: ffff949da6f20000 CPU: 23 COMMAND: "vhost-32980" #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e #3 [fffffe00003fced0] do_nmi at ffffffff8922660d #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663 [exception RIP: io_serial_in+20] RIP: ffffffff89792594 RSP: ffffa655314979e8 RFLAGS: 00000002 RAX: ffffffff89792500 RBX: ffffffff8af428a0 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff8af428a0 RBP: 0000000000002710 R8: 0000000000000004 R9: 000000000000000f R10: 0000000000000000 R11: ffffffff8acbf64f R12: 0000000000000020 R13: ffffffff8acbf698 R14: 0000000000000058 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594 #6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470 #7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6 torvalds#8 [ffffa65531497a20] uart_console_write at ffffffff8978b605 torvalds#9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558 torvalds#10 [ffffa65531497ac8] console_unlock at ffffffff89316124 torvalds#11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07 #12 [ffffa65531497b68] printk at ffffffff89318306 #13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765 torvalds#14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun] #15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun] #16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net] #17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost] #18 [ffffa65531497f10] kthread at ffffffff892d2e72 #19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors") Signed-off-by: Lei Chen <[email protected]> Reviewed-by: Willem de Bruijn <[email protected]> Acked-by: Jason Wang <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Acked-by: Michael S. Tsirkin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>

ui_browser__show() is capturing the input title that is stack allocated memory in hist_browser__run(). Avoid a use after return by strdup-ing the string. Committer notes: Further explanation from Ian Rogers: My command line using tui is: $ sudo bash -c 'rm /tmp/asan.log*; export ASAN_OPTIONS="log_path=/tmp/asan.log"; /tmp/perf/perf mem record -a sleep 1; /tmp/perf/perf mem report' I then go to the perf annotate view and quit. This triggers the asan error (from the log file): ``` ==1254591==ERROR: AddressSanitizer: stack-use-after-return on address 0x7f2813331920 at pc 0x7f28180 65991 bp 0x7fff0a21c750 sp 0x7fff0a21bf10 READ of size 80 at 0x7f2813331920 thread T0 #0 0x7f2818065990 in __interceptor_strlen ../../../../src/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:461 #1 0x7f2817698251 in SLsmg_write_wrapped_string (/lib/x86_64-linux-gnu/libslang.so.2+0x98251) #2 0x7f28176984b9 in SLsmg_write_nstring (/lib/x86_64-linux-gnu/libslang.so.2+0x984b9) #3 0x55c94045b365 in ui_browser__write_nstring ui/browser.c:60 #4 0x55c94045c558 in __ui_browser__show_title ui/browser.c:266 #5 0x55c94045c776 in ui_browser__show ui/browser.c:288 #6 0x55c94045c06d in ui_browser__handle_resize ui/browser.c:206 #7 0x55c94047979b in do_annotate ui/browsers/hists.c:2458 torvalds#8 0x55c94047fb17 in evsel__hists_browse ui/browsers/hists.c:3412 torvalds#9 0x55c940480a0c in perf_evsel_menu__run ui/browsers/hists.c:3527 torvalds#10 0x55c940481108 in __evlist__tui_browse_hists ui/browsers/hists.c:3613 torvalds#11 0x55c9404813f7 in evlist__tui_browse_hists ui/browsers/hists.c:3661 #12 0x55c93ffa253f in report__browse_hists tools/perf/builtin-report.c:671 #13 0x55c93ffa58ca in __cmd_report tools/perf/builtin-report.c:1141 torvalds#14 0x55c93ffaf159 in cmd_report tools/perf/builtin-report.c:1805 #15 0x55c94000c05c in report_events tools/perf/builtin-mem.c:374 #16 0x55c94000d96d in cmd_mem tools/perf/builtin-mem.c:516 #17 0x55c9400e44ee in run_builtin tools/perf/perf.c:350 #18 0x55c9400e4a5a in handle_internal_command tools/perf/perf.c:403 #19 0x55c9400e4e22 in run_argv tools/perf/perf.c:447 #20 0x55c9400e53ad in main tools/perf/perf.c:561 #21 0x7f28170456c9 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58 #22 0x7f2817045784 in __libc_start_main_impl ../csu/libc-start.c:360 #23 0x55c93ff544c0 in _start (/tmp/perf/perf+0x19a4c0) (BuildId: 84899b0e8c7d3a3eaa67b2eb35e3d8b2f8cd4c93) Address 0x7f2813331920 is located in stack of thread T0 at offset 32 in frame #0 0x55c94046e85e in hist_browser__run ui/browsers/hists.c:746 This frame has 1 object(s): [32, 192) 'title' (line 747) <== Memory access at offset 32 is inside this variable HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork ``` hist_browser__run isn't on the stack so the asan error looks legit. There's no clean init/exit on struct ui_browser so I may be trading a use-after-return for a memory leak, but that seems look a good trade anyway. Fixes: 05e8b08 ("perf ui browser: Stop using 'self'") Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Athira Rajeev <[email protected]> Cc: Ben Gainey <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: James Clark <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kajol Jain <[email protected]> Cc: Kan Liang <[email protected]> Cc: K Prateek Nayak <[email protected]> Cc: Li Dong <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Oliver Upton <[email protected]> Cc: Paran Lee <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Bangoria <[email protected]> Cc: Sun Haiyong <[email protected]> Cc: Tim Chen <[email protected]> Cc: Yanteng Si <[email protected]> Cc: Yicong Yang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) #1 btrfs_drop_extents (fs/btrfs/file.c:411:4) #2 log_one_extent (fs/btrfs/tree-log.c:4732:9) #3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) #4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) #5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) #6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) #7 btrfs_sync_file (fs/btrfs/file.c:1933:8) torvalds#8 vfs_fsync_range (fs/sync.c:188:9) torvalds#9 vfs_fsync (fs/sync.c:202:9) torvalds#10 do_fsync (fs/sync.c:212:9) torvalds#11 __do_sys_fdatasync (fs/sync.c:225:9) #12 __se_sys_fdatasync (fs/sync.c:223:1) #13 __x64_sys_fdatasync (fs/sync.c:223:1) torvalds#14 do_syscall_x64 (arch/x86/entry/common.c:52:14) #15 do_syscall_64 (arch/x86/entry/common.c:83:7) #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Omar Sandoval <[email protected]>

We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) #1 btrfs_drop_extents (fs/btrfs/file.c:411:4) #2 log_one_extent (fs/btrfs/tree-log.c:4732:9) #3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) #4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) #5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) #6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) #7 btrfs_sync_file (fs/btrfs/file.c:1933:8) torvalds#8 vfs_fsync_range (fs/sync.c:188:9) torvalds#9 vfs_fsync (fs/sync.c:202:9) torvalds#10 do_fsync (fs/sync.c:212:9) torvalds#11 __do_sys_fdatasync (fs/sync.c:225:9) #12 __se_sys_fdatasync (fs/sync.c:223:1) #13 __x64_sys_fdatasync (fs/sync.c:223:1) torvalds#14 do_syscall_x64 (arch/x86/entry/common.c:52:14) #15 do_syscall_64 (arch/x86/entry/common.c:83:7) #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Signed-off-by: David Sterba <[email protected]>

We have been seeing crashes on duplicate keys in btrfs_set_item_key_safe(): BTRFS critical (device vdb): slot 4 key (450 108 8192) new key (450 108 8192) ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.c:2620! invalid opcode: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 3139 Comm: xfs_io Kdump: loaded Not tainted 6.9.0 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 RIP: 0010:btrfs_set_item_key_safe+0x11f/0x290 [btrfs] With the following stack trace: #0 btrfs_set_item_key_safe (fs/btrfs/ctree.c:2620:4) #1 btrfs_drop_extents (fs/btrfs/file.c:411:4) #2 log_one_extent (fs/btrfs/tree-log.c:4732:9) #3 btrfs_log_changed_extents (fs/btrfs/tree-log.c:4955:9) #4 btrfs_log_inode (fs/btrfs/tree-log.c:6626:9) #5 btrfs_log_inode_parent (fs/btrfs/tree-log.c:7070:8) #6 btrfs_log_dentry_safe (fs/btrfs/tree-log.c:7171:8) #7 btrfs_sync_file (fs/btrfs/file.c:1933:8) torvalds#8 vfs_fsync_range (fs/sync.c:188:9) torvalds#9 vfs_fsync (fs/sync.c:202:9) torvalds#10 do_fsync (fs/sync.c:212:9) torvalds#11 __do_sys_fdatasync (fs/sync.c:225:9) #12 __se_sys_fdatasync (fs/sync.c:223:1) #13 __x64_sys_fdatasync (fs/sync.c:223:1) torvalds#14 do_syscall_x64 (arch/x86/entry/common.c:52:14) #15 do_syscall_64 (arch/x86/entry/common.c:83:7) #16 entry_SYSCALL_64+0xaf/0x14c (arch/x86/entry/entry_64.S:121) So we're logging a changed extent from fsync, which is splitting an extent in the log tree. But this split part already exists in the tree, triggering the BUG(). This is the state of the log tree at the time of the crash, dumped with drgn (https://github.com/osandov/drgn/blob/main/contrib/btrfs_tree.py) to get more details than btrfs_print_leaf() gives us: >>> print_extent_buffer(prog.crashed_thread().stack_trace()[0]["eb"]) leaf 33439744 level 0 items 72 generation 9 owner 18446744073709551610 leaf 33439744 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da item 0 key (450 INODE_ITEM 0) itemoff 16123 itemsize 160 generation 7 transid 9 size 8192 nbytes 8473563889606862198 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 204 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417704.983333333 (2024-05-22 15:41:44) mtime 1716417704.983333333 (2024-05-22 15:41:44) otime 17592186044416.000000000 (559444-03-08 01:40:16) item 1 key (450 INODE_REF 256) itemoff 16110 itemsize 13 index 195 namelen 3 name: 193 item 2 key (450 XATTR_ITEM 1640047104) itemoff 16073 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 3 key (450 EXTENT_DATA 0) itemoff 16020 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 4096 ram 12288 extent compression 0 (none) item 4 key (450 EXTENT_DATA 4096) itemoff 15967 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 4096 nr 8192 item 5 key (450 EXTENT_DATA 8192) itemoff 15914 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 ... So the real problem happened earlier: notice that items 4 (4k-12k) and 5 (8k-12k) overlap. Both are prealloc extents. Item 4 straddles i_size and item 5 starts at i_size. Here is the state of the filesystem tree at the time of the crash: >>> root = prog.crashed_thread().stack_trace()[2]["inode"].root >>> ret, nodes, slots = btrfs_search_slot(root, BtrfsKey(450, 0, 0)) >>> print_extent_buffer(nodes[0]) leaf 30425088 level 0 items 184 generation 9 owner 5 leaf 30425088 flags 0x100000000000000 fs uuid e5bd3946-400c-4223-8923-190ef1f18677 chunk uuid d58cb17e-6d02-494a-829a-18b7d8a399da ... item 179 key (450 INODE_ITEM 0) itemoff 4907 itemsize 160 generation 7 transid 7 size 4096 nbytes 12288 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 6 flags 0x10(PREALLOC) atime 1716417703.220000000 (2024-05-22 15:41:43) ctime 1716417703.220000000 (2024-05-22 15:41:43) mtime 1716417703.220000000 (2024-05-22 15:41:43) otime 1716417703.220000000 (2024-05-22 15:41:43) item 180 key (450 INODE_REF 256) itemoff 4894 itemsize 13 index 195 namelen 3 name: 193 item 181 key (450 XATTR_ITEM 1640047104) itemoff 4857 itemsize 37 location key (0 UNKNOWN.0 0) type XATTR transid 7 data_len 1 name_len 6 name: user.a data a item 182 key (450 EXTENT_DATA 0) itemoff 4804 itemsize 53 generation 9 type 1 (regular) extent data disk byte 303144960 nr 12288 extent data offset 0 nr 8192 ram 12288 extent compression 0 (none) item 183 key (450 EXTENT_DATA 8192) itemoff 4751 itemsize 53 generation 9 type 2 (prealloc) prealloc data disk byte 303144960 nr 12288 prealloc data offset 8192 nr 4096 Item 5 in the log tree corresponds to item 183 in the filesystem tree, but nothing matches item 4. Furthermore, item 183 is the last item in the leaf. btrfs_log_prealloc_extents() is responsible for logging prealloc extents beyond i_size. It first truncates any previously logged prealloc extents that start beyond i_size. Then, it walks the filesystem tree and copies the prealloc extent items to the log tree. If it hits the end of a leaf, then it calls btrfs_next_leaf(), which unlocks the tree and does another search. However, while the filesystem tree is unlocked, an ordered extent completion may modify the tree. In particular, it may insert an extent item that overlaps with an extent item that was already copied to the log tree. This may manifest in several ways depending on the exact scenario, including an EEXIST error that is silently translated to a full sync, overlapping items in the log tree, or this crash. This particular crash is triggered by the following sequence of events: - Initially, the file has i_size=4k, a regular extent from 0-4k, and a prealloc extent beyond i_size from 4k-12k. The prealloc extent item is the last item in its B-tree leaf. - The file is fsync'd, which copies its inode item and both extent items to the log tree. - An xattr is set on the file, which sets the BTRFS_INODE_COPY_EVERYTHING flag. - The range 4k-8k in the file is written using direct I/O. i_size is extended to 8k, but the ordered extent is still in flight. - The file is fsync'd. Since BTRFS_INODE_COPY_EVERYTHING is set, this calls copy_inode_items_to_log(), which calls btrfs_log_prealloc_extents(). - btrfs_log_prealloc_extents() finds the 4k-12k prealloc extent in the filesystem tree. Since it starts before i_size, it skips it. Since it is the last item in its B-tree leaf, it calls btrfs_next_leaf(). - btrfs_next_leaf() unlocks the path. - The ordered extent completion runs, which converts the 4k-8k part of the prealloc extent to written and inserts the remaining prealloc part from 8k-12k. - btrfs_next_leaf() does a search and finds the new prealloc extent 8k-12k. - btrfs_log_prealloc_extents() copies the 8k-12k prealloc extent into the log tree. Note that it overlaps with the 4k-12k prealloc extent that was copied to the log tree by the first fsync. - fsync calls btrfs_log_changed_extents(), which tries to log the 4k-8k extent that was written. - This tries to drop the range 4k-8k in the log tree, which requires adjusting the start of the 4k-12k prealloc extent in the log tree to 8k. - btrfs_set_item_key_safe() sees that there is already an extent starting at 8k in the log tree and calls BUG(). Fix this by detecting when we're about to insert an overlapping file extent item in the log tree and truncating the part that would overlap. CC: [email protected] # 6.1+ Reviewed-by: Filipe Manana <[email protected]> Signed-off-by: Omar Sandoval <[email protected]> Signed-off-by: David Sterba <[email protected]>

The code in ocfs2_dio_end_io_write() estimates number of necessary transaction credits using ocfs2_calc_extend_credits(). This however does not take into account that the IO could be arbitrarily large and can contain arbitrary number of extents. Extent tree manipulations do often extend the current transaction but not in all of the cases. For example if we have only single block extents in the tree, ocfs2_mark_extent_written() will end up calling ocfs2_replace_extent_rec() all the time and we will never extend the current transaction and eventually exhaust all the transaction credits if the IO contains many single block extents. Once that happens a WARN_ON(jbd2_handle_buffer_credits(handle) <= 0) is triggered in jbd2_journal_dirty_metadata() and subsequently OCFS2 aborts in response to this error. This was actually triggered by one of our customers on a heavily fragmented OCFS2 filesystem. To fix the issue make sure the transaction always has enough credits for one extent insert before each call of ocfs2_mark_extent_written(). Heming Zhao said: ------ PANIC: "Kernel panic - not syncing: OCFS2: (device dm-1): panic forced after error" PID: xxx TASK: xxxx CPU: 5 COMMAND: "SubmitThread-CA" #0 machine_kexec at ffffffff8c069932 #1 __crash_kexec at ffffffff8c1338fa #2 panic at ffffffff8c1d69b9 #3 ocfs2_handle_error at ffffffffc0c86c0c [ocfs2] #4 __ocfs2_abort at ffffffffc0c88387 [ocfs2] #5 ocfs2_journal_dirty at ffffffffc0c51e98 [ocfs2] #6 ocfs2_split_extent at ffffffffc0c27ea3 [ocfs2] #7 ocfs2_change_extent_flag at ffffffffc0c28053 [ocfs2] torvalds#8 ocfs2_mark_extent_written at ffffffffc0c28347 [ocfs2] torvalds#9 ocfs2_dio_end_io_write at ffffffffc0c2bef9 [ocfs2] torvalds#10 ocfs2_dio_end_io at ffffffffc0c2c0f5 [ocfs2] torvalds#11 dio_complete at ffffffff8c2b9fa7 #12 do_blockdev_direct_IO at ffffffff8c2bc09f #13 ocfs2_direct_IO at ffffffffc0c2b653 [ocfs2] torvalds#14 generic_file_direct_write at ffffffff8c1dcf14 #15 __generic_file_write_iter at ffffffff8c1dd07b #16 ocfs2_file_write_iter at ffffffffc0c49f1f [ocfs2] #17 aio_write at ffffffff8c2cc72e #18 kmem_cache_alloc at ffffffff8c248dde #19 do_io_submit at ffffffff8c2ccada #20 do_syscall_64 at ffffffff8c004984 #21 entry_SYSCALL_64_after_hwframe at ffffffff8c8000ba Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: c15471f ("ocfs2: fix sparse file & data ordering issue in direct io") Signed-off-by: Jan Kara <[email protected]> Reviewed-by: Joseph Qi <[email protected]> Reviewed-by: Heming Zhao <[email protected]> Cc: Mark Fasheh <[email protected]> Cc: Joel Becker <[email protected]> Cc: Junxiao Bi <[email protected]> Cc: Changwei Ge <[email protected]> Cc: Gang He <[email protected]> Cc: Jun Piao <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>

syzkaller triggered the warning [0] in udp_v4_early_demux(). In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount of the looked-up sk and use sock_pfree() as skb->destructor, so we check SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace period. Currently, SOCK_RCU_FREE is flagged for a bound socket after being put into the hash table. Moreover, the SOCK_RCU_FREE check is done too early in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race window: CPU1 CPU2 ---- ---- udp_v4_early_demux() udp_lib_get_port() | |- hlist_add_head_rcu() |- sk = __udp4_lib_demux_lookup() | |- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); `- sock_set_flag(sk, SOCK_RCU_FREE) We had the same bug in TCP and fixed it in commit 871019b ("net: set SOCK_RCU_FREE before inserting socket into hashtable"). Let's apply the same fix for UDP. [0]: WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Modules linked in: CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Code: c5 7a 15 fe bb 01 00 00 00 44 89 e9 31 ff d3 e3 81 e3 bf ef ff ff 89 de e8 2c 74 15 fe 85 db 0f 85 02 06 00 00 e8 9f 7a 15 fe <0f> 0b e8 98 7a 15 fe 49 8d 7e 60 e8 4f 39 2f fe 49 c7 46 60 20 52 RSP: 0018:ffffc9000ce3fa58 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8318c92c RDX: ffff888036ccde00 RSI: ffffffff8318c2f1 RDI: 0000000000000001 RBP: ffff88805a2dd6e0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0001ffffffffffff R12: ffff88805a2dd680 R13: 0000000000000007 R14: ffff88800923f900 R15: ffff88805456004e FS: 00007fc449127640(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc449126e38 CR3: 000000003de4b002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <TASK> ip_rcv_finish_core.constprop.0+0xbdd/0xd20 net/ipv4/ip_input.c:349 ip_rcv_finish+0xda/0x150 net/ipv4/ip_input.c:447 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x16c/0x180 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0xb3/0xe0 net/core/dev.c:5624 __netif_receive_skb+0x21/0xd0 net/core/dev.c:5738 netif_receive_skb_internal net/core/dev.c:5824 [inline] netif_receive_skb+0x271/0x300 net/core/dev.c:5884 tun_rx_batched drivers/net/tun.c:1549 [inline] tun_get_user+0x24db/0x2c50 drivers/net/tun.c:2002 tun_chr_write_iter+0x107/0x1a0 drivers/net/tun.c:2048 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x76f/0x8d0 fs/read_write.c:590 ksys_write+0xbf/0x190 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x41/0x50 fs/read_write.c:652 x64_sys_call+0xe66/0x1990 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fc44a68bc1f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 e9 cf f5 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 3c d0 f5 ff 48 RSP: 002b:00007fc449126c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007fc44a68bc1f RDX: 0000000000000032 RSI: 00000000200000c0 RDI: 00000000000000c8 RBP: 00000000004bc050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000032 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc44a5ec530 R15: 0000000000000000 </TASK> Fixes: 6acc9b4 ("bpf: Add helper to retrieve socket in BPF") Reported-by: syzkaller <[email protected]> Signed-off-by: Kuniyuki Iwashima <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Paolo Abeni <[email protected]>

…rnel/git/netfilter/nf-next into main Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS updates for net-next: Patch #1 to torvalds#11 to shrink memory consumption for transaction objects: struct nft_trans_chain { /* size: 120 (-32), cachelines: 2, members: 10 */ struct nft_trans_elem { /* size: 72 (-40), cachelines: 2, members: 4 */ struct nft_trans_flowtable { /* size: 80 (-48), cachelines: 2, members: 5 */ struct nft_trans_obj { /* size: 72 (-40), cachelines: 2, members: 4 */ struct nft_trans_rule { /* size: 80 (-32), cachelines: 2, members: 6 */ struct nft_trans_set { /* size: 96 (-24), cachelines: 2, members: 8 */ struct nft_trans_table { /* size: 56 (-40), cachelines: 1, members: 2 */ struct nft_trans_elem can now be allocated from kmalloc-96 instead of kmalloc-128 slab. Series from Florian Westphal. For the record, I have mangled patch #1 to add nft_trans_container_*() and use if for every transaction object. I have also added BUILD_BUG_ON to ensure struct nft_trans always comes at the beginning of the container transaction object. And few minor cleanups, any new bugs are of my own. Patch #12 simplify check for SCTP GSO in IPVS, from Ismael Luceno. Patch #13 nf_conncount key length remains in the u32 bound, from Yunjian Wang. Patch torvalds#14 removes unnecessary check for CTA_TIMEOUT_L3PROTO when setting default conntrack timeouts via nfnetlink_cttimeout API, from Lin Ma. Patch #15 updates NFT_SECMARK_CTX_MAXLEN to 4096, SELinux could use larger secctx names than the existing 256 bytes length. Patch #16 adds a selftest to exercise nfnetlink_queue listeners leaving nfnetlink_queue, from Florian Westphal. Patch #17 increases hitcount from 255 to 65535 in xt_recent, from Phil Sutter. ==================== Signed-off-by: David S. Miller <[email protected]>

A sysfs reader can race with a device reset or removal, attempting to read device state when the device is not actually present. eg: [exception RIP: qed_get_current_link+17] torvalds#8 [ffffb9e4f2907c48] qede_get_link_ksettings at ffffffffc07a994a [qede] torvalds#9 [ffffb9e4f2907cd8] __rh_call_get_link_ksettings at ffffffff992b01a3 torvalds#10 [ffffb9e4f2907d38] __ethtool_get_link_ksettings at ffffffff992b04e4 torvalds#11 [ffffb9e4f2907d90] duplex_show at ffffffff99260300 #12 [ffffb9e4f2907e38] dev_attr_show at ffffffff9905a01c #13 [ffffb9e4f2907e50] sysfs_kf_seq_show at ffffffff98e0145b torvalds#14 [ffffb9e4f2907e68] seq_read at ffffffff98d902e3 #15 [ffffb9e4f2907ec8] vfs_read at ffffffff98d657d1 #16 [ffffb9e4f2907f00] ksys_read at ffffffff98d65c3f #17 [ffffb9e4f2907f38] do_syscall_64 at ffffffff98a052fb crash> struct net_device.state ffff9a9d21336000 state = 5, state 5 is __LINK_STATE_START (0b1) and __LINK_STATE_NOCARRIER (0b100). The device is not present, note lack of __LINK_STATE_PRESENT (0b10). This is the same sort of panic as observed in commit 4224cfd ("net-sysfs: add check for netdevice being present to speed_show"). There are many other callers of __ethtool_get_link_ksettings() which don't have a device presence check. Move this check into ethtool to protect all callers. Fixes: d519e17 ("net: export device speed and duplex via sysfs") Fixes: 4224cfd ("net-sysfs: add check for netdevice being present to speed_show") Signed-off-by: Jamie Bainbridge <[email protected]> Link: https://patch.msgid.link/8bae218864beaa44ed01628140475b9bf641c5b0.1724393671.git.jamie.bainbridge@gmail.com Signed-off-by: Jakub Kicinski <[email protected]>

Add nested locking with I_MUTEX_XATTR subclass to avoid lockdep warning while handling xattr inode on file open syscall at ext4_xattr_inode_iget. Backtrace EXT4-fs (loop0): Ignoring removed oldalloc option ====================================================== WARNING: possible circular locking dependency detected 5.10.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor543/2794 is trying to acquire lock: ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline] ffff8880215e1a48 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}, at: ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425 but task is already holding lock: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ei->i_data_sem/3){++++}-{3:3}: lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566 down_write+0x93/0x180 kernel/locking/rwsem.c:1564 ext4_update_i_disksize fs/ext4/ext4.h:3267 [inline] ext4_xattr_inode_write fs/ext4/xattr.c:1390 [inline] ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1538 [inline] ext4_xattr_set_entry+0x331a/0x3d80 fs/ext4/xattr.c:1662 ext4_xattr_ibody_set+0x124/0x390 fs/ext4/xattr.c:2228 ext4_xattr_set_handle+0xc27/0x14e0 fs/ext4/xattr.c:2385 ext4_xattr_set+0x219/0x390 fs/ext4/xattr.c:2498 ext4_xattr_user_set+0xc9/0xf0 fs/ext4/xattr_user.c:40 __vfs_setxattr+0x404/0x450 fs/xattr.c:177 __vfs_setxattr_noperm+0x11d/0x4f0 fs/xattr.c:208 __vfs_setxattr_locked+0x1f9/0x210 fs/xattr.c:266 vfs_setxattr+0x112/0x2c0 fs/xattr.c:283 setxattr+0x1db/0x3e0 fs/xattr.c:548 path_setxattr+0x15a/0x240 fs/xattr.c:567 __do_sys_setxattr fs/xattr.c:582 [inline] __se_sys_setxattr fs/xattr.c:578 [inline] __x64_sys_setxattr+0xc5/0xe0 fs/xattr.c:578 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62 entry_SYSCALL_64_after_hwframe+0x61/0xcb -> #0 (&ea_inode->i_rwsem#7/1){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566 down_write+0x93/0x180 kernel/locking/rwsem.c:1564 inode_lock include/linux/fs.h:782 [inline] ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline] ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline] __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562 notify_change+0xbb6/0xe60 fs/attr.c:435 do_truncate+0x1de/0x2c0 fs/open.c:64 handle_truncate fs/namei.c:2970 [inline] do_open fs/namei.c:3311 [inline] path_openat+0x29f3/0x3290 fs/namei.c:3425 do_filp_open+0x20b/0x450 fs/namei.c:3452 do_sys_openat2+0x124/0x460 fs/open.c:1207 do_sys_open fs/open.c:1223 [inline] __do_sys_open fs/open.c:1231 [inline] __se_sys_open fs/open.c:1227 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1227 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62 entry_SYSCALL_64_after_hwframe+0x61/0xcb other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->i_data_sem/3); lock(&ea_inode->i_rwsem#7/1); lock(&ei->i_data_sem/3); lock(&ea_inode->i_rwsem#7/1); *** DEADLOCK *** 5 locks held by syz-executor543/2794: #0: ffff888026fbc448 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x4a/0x2a0 fs/namespace.c:365 #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:782 [inline] #1: ffff8880215e3488 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: do_truncate+0x1cf/0x2c0 fs/open.c:62 #2: ffff8880215e3310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_setattr+0xec4/0x19c0 fs/ext4/inode.c:5519 #3: ffff8880215e3278 (&ei->i_data_sem/3){++++}-{3:3}, at: ext4_setattr+0x136d/0x19c0 fs/ext4/inode.c:5559 #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline] #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:5938 [inline] #4: ffff8880215e30c8 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x4fb/0x810 fs/ext4/inode.c:6018 stack backtrace: CPU: 1 PID: 2794 Comm: syz-executor543 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x177/0x211 lib/dump_stack.c:118 print_circular_bug+0x146/0x1b0 kernel/locking/lockdep.c:2002 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain+0x1695/0x58f0 kernel/locking/lockdep.c:3729 __lock_acquire+0x12fd/0x20d0 kernel/locking/lockdep.c:4955 lock_acquire+0x197/0x480 kernel/locking/lockdep.c:5566 down_write+0x93/0x180 kernel/locking/rwsem.c:1564 inode_lock include/linux/fs.h:782 [inline] ext4_xattr_inode_iget+0x42a/0x5c0 fs/ext4/xattr.c:425 ext4_xattr_inode_get+0x138/0x410 fs/ext4/xattr.c:485 ext4_xattr_move_to_block fs/ext4/xattr.c:2580 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2682 [inline] ext4_expand_extra_isize_ea+0xe70/0x1bb0 fs/ext4/xattr.c:2774 __ext4_expand_extra_isize+0x304/0x3f0 fs/ext4/inode.c:5898 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5941 [inline] __ext4_mark_inode_dirty+0x591/0x810 fs/ext4/inode.c:6018 ext4_setattr+0x1400/0x19c0 fs/ext4/inode.c:5562 notify_change+0xbb6/0xe60 fs/attr.c:435 do_truncate+0x1de/0x2c0 fs/open.c:64 handle_truncate fs/namei.c:2970 [inline] do_open fs/namei.c:3311 [inline] path_openat+0x29f3/0x3290 fs/namei.c:3425 do_filp_open+0x20b/0x450 fs/namei.c:3452 do_sys_openat2+0x124/0x460 fs/open.c:1207 do_sys_open fs/open.c:1223 [inline] __do_sys_open fs/open.c:1231 [inline] __se_sys_open fs/open.c:1227 [inline] __x64_sys_open+0x221/0x270 fs/open.c:1227 do_syscall_64+0x6d/0xa0 arch/x86/entry/common.c:62 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f0cde4ea229 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd81d1c978 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0030656c69662f30 RCX: 00007f0cde4ea229 RDX: 0000000000000089 RSI: 00000000000a0a00 RDI: 00000000200001c0 RBP: 2f30656c69662f2e R08: 0000000000208000 R09: 0000000000208000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd81d1c9c0 R13: 00007ffd81d1ca00 R14: 0000000000080000 R15: 0000000000000003 EXT4-fs error (device loop0): ext4_expand_extra_isize_ea:2730: inode #13: comm syz-executor543: corrupted in-inode xattr Signed-off-by: Wojciech Gładysz <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Theodore Ts'o <[email protected]>

The fields in the hist_entry are filled on-demand which means they only have meaningful values when relevant sort keys are used. So if neither of 'dso' nor 'sym' sort keys are used, the map/symbols in the hist entry can be garbage. So it shouldn't access it unconditionally. I got a segfault, when I wanted to see cgroup profiles. $ sudo perf record -a --all-cgroups --synth=cgroup true $ sudo perf report -s cgroup Program received signal SIGSEGV, Segmentation fault. 0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48 48 return RC_CHK_ACCESS(map)->dso; (gdb) bt #0 0x00005555557a8d90 in map__dso (map=0x0) at util/map.h:48 #1 0x00005555557aa39b in map__load (map=0x0) at util/map.c:344 #2 0x00005555557aa592 in map__find_symbol (map=0x0, addr=140736115941088) at util/map.c:385 #3 0x00005555557ef000 in hists__findnew_entry (hists=0x555556039d60, entry=0x7fffffffa4c0, al=0x7fffffffa8c0, sample_self=true) at util/hist.c:644 #4 0x00005555557ef61c in __hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0, block_info=0x0, sample=0x7fffffffaa90, sample_self=true, ops=0x0) at util/hist.c:761 #5 0x00005555557ef71f in hists__add_entry (hists=0x555556039d60, al=0x7fffffffa8c0, sym_parent=0x0, bi=0x0, mi=0x0, ki=0x0, sample=0x7fffffffaa90, sample_self=true) at util/hist.c:779 #6 0x00005555557f00fb in iter_add_single_normal_entry (iter=0x7fffffffa900, al=0x7fffffffa8c0) at util/hist.c:1015 #7 0x00005555557f09a7 in hist_entry_iter__add (iter=0x7fffffffa900, al=0x7fffffffa8c0, max_stack_depth=127, arg=0x7fffffffbce0) at util/hist.c:1260 torvalds#8 0x00005555555ba7ce in process_sample_event (tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at builtin-report.c:334 torvalds#9 0x00005555557b30c8 in evlist__deliver_sample (evlist=0x555556039010, tool=0x7fffffffbce0, event=0x7ffff7c14128, sample=0x7fffffffaa90, evsel=0x555556039ad0, machine=0x5555560388e8) at util/session.c:1232 torvalds#10 0x00005555557b32bc in machines__deliver_event (machines=0x5555560388e8, evlist=0x555556039010, event=0x7ffff7c14128, sample=0x7fffffffaa90, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1271 torvalds#11 0x00005555557b3848 in perf_session__deliver_event (session=0x5555560386d0, event=0x7ffff7c14128, tool=0x7fffffffbce0, file_offset=110888, file_path=0x555556038ff0 "perf.data") at util/session.c:1354 #12 0x00005555557affaf in ordered_events__deliver_event (oe=0x555556038e60, event=0x555556135aa0) at util/session.c:132 #13 0x00005555557bb605 in do_flush (oe=0x555556038e60, show_progress=false) at util/ordered-events.c:245 torvalds#14 0x00005555557bb95c in __ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND, timestamp=0) at util/ordered-events.c:324 #15 0x00005555557bba46 in ordered_events__flush (oe=0x555556038e60, how=OE_FLUSH__ROUND) at util/ordered-events.c:342 #16 0x00005555557b1b3b in perf_event__process_finished_round (tool=0x7fffffffbce0, event=0x7ffff7c15bb8, oe=0x555556038e60) at util/session.c:780 #17 0x00005555557b3b27 in perf_session__process_user_event (session=0x5555560386d0, event=0x7ffff7c15bb8, file_offset=117688, file_path=0x555556038ff0 "perf.data") at util/session.c:1406 As you can see the entry->ms.map was NULL even if he->ms.map has a value. This is because 'sym' sort key is not given, so it cannot assume whether he->ms.sym and entry->ms.sym is the same. I only checked the 'sym' sort key here as it implies 'dso' behavior (so maps are the same). Fixes: ac01c8c ("perf hist: Update hist symbol when updating maps") Signed-off-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kan Liang <[email protected]> Cc: Matt Fleming <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Hou Tao says: ==================== The use of migrate_{disable|enable} pair in BPF is mainly due to the introduction of bpf memory allocator and the use of per-CPU data struct in its internal implementation. The caller needs to disable migration before invoking the alloc or free APIs of bpf memory allocator, and enable migration after the invocation. The main users of bpf memory allocator are various kind of bpf maps in which the map values or the special fields in the map values are allocated by using bpf memory allocator. At present, the running context for bpf program has already disabled migration explictly or implictly, therefore, when these maps are manipulated in bpf program, it is OK to not invoke migrate_disable() and migrate_enable() pair. Howevers, it is not always the case when these maps are manipulated through bpf syscall, therefore many migrate_{disable|enable} pairs are added when the map can either be manipulated by BPF program or BPF syscall. The initial idea of reducing the use of migrate_{disable|enable} comes from Alexei [1]. I turned it into a patch set that archives the goals through the following three methods: 1. remove unnecessary migrate_{disable|enable} pair when the BPF syscall path also disables migration, it is OK to remove the pair. Patch #1~#3 fall into this category, while patch #4~#5 are partially included. 2. move the migrate_{disable|enable} pair from inner callee to outer caller Instead of invoking migrate_disable() in the inner callee, invoking migrate_disable() in the outer caller to simplify reasoning about when migrate_disable() is needed. Patch #4~#5 and patch #6~#19 belongs to this category. 3. add cant_migrate() check in the inner callee Add cant_migrate() check in the inner callee to ensure the guarantee that migration is disabled is not broken. Patch #1~#5, #13, #16~#19 also belong to this category. Please check the individual patches for more details. Comments are always welcome. Change Log: v2: * sqaush the ->map_free related patches (torvalds#10~#12, #15) into one patch * remove unnecessary cant_migrate() checks. v1: https://lore.kernel.org/bpf/[email protected] ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>

josefbacik added the tricky label Aug 26, 2020

kdave added the 5.10 label Sep 9, 2020

kdave added partial and removed 5.11 labels Oct 15, 2020

kdave removed the tricky label Oct 23, 2020

kdave added misc-next patches are in misc-next and removed partial labels Nov 3, 2020

kdave removed the misc-next patches are in misc-next label Dec 14, 2020

kdave closed this as completed Dec 14, 2020

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[PATCH 00/12] Convert btree locking to an rwsem #13

[PATCH 00/12] Convert btree locking to an rwsem #13

josefbacik commented Aug 20, 2020