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* [PATCH -tip v11 00/27] kprobes: Fix stacktrace with kretprobes on x86
@ 2021-09-14 14:38 ` Masami Hiramatsu
  0 siblings, 0 replies; 76+ messages in thread
From: Masami Hiramatsu @ 2021-09-14 14:38 UTC (permalink / raw)
  To: Steven Rostedt, Josh Poimboeuf, Ingo Molnar
  Cc: X86 ML, Masami Hiramatsu, Daniel Xu, linux-kernel, bpf, kuba,
	mingo, ast, Thomas Gleixner, Borislav Petkov, Peter Zijlstra,
	kernel-team, yhs, linux-ia64, Abhishek Sagar, Andrii Nakryiko,
	Paul McKenney

Hello,

This is the 11th version of the series to fix the stacktrace with kretprobe on x86.

The previous version is here;

 https://lore.kernel.org/all/162756755600.301564.4957591913842010341.stgit@devnote2/

This version is rebased on the latest tip/master branch and includes the kprobe cleanup
series[1][2]. No code change.

[1] https://lore.kernel.org/bpf/162748615977.59465.13262421617578791515.stgit@devnote2/
[2] https://lore.kernel.org/linux-csky/20210727133426.2919710-1-punitagrawal@gmail.com/


With this series, unwinder can unwind stack correctly from ftrace as below;

  # cd /sys/kernel/debug/tracing
  # echo > trace
  # echo 1 > options/sym-offset
  # echo r vfs_read >> kprobe_events
  # echo r full_proxy_read >> kprobe_events
  # echo traceoff:1 > events/kprobes/r_vfs_read_0/trigger
  # echo stacktrace:1 > events/kprobes/r_full_proxy_read_0/trigger
  # echo 1 > events/kprobes/enable
  # cat /sys/kernel/debug/kprobes/list
ffffffff813bedf0  r  full_proxy_read+0x0    [FTRACE]
ffffffff812c13e0  r  vfs_read+0x0    [FTRACE]
  # echo 0 > events/kprobes/enable
  # cat trace
# tracer: nop
#
# entries-in-buffer/entries-written: 3/3   #P:8
#
#                                _-----=> irqs-off
#                               / _----=> need-resched
#                              | / _---=> hardirq/softirq
#                              || / _--=> preempt-depth
#                              ||| / _-=> migrate-disable
#                              |||| /     delay
#           TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
#              | |         |   |||||     |         |
             cat-136     [000] ...1.    14.474966: r_full_proxy_read_0: (vfs_read+0x99/0x190 <- full_proxy_read)
             cat-136     [000] ...1.    14.474970: <stack trace>
 => kretprobe_trace_func+0x209/0x300
 => kretprobe_dispatcher+0x9d/0xb0
 => __kretprobe_trampoline_handler+0xd4/0x1b0
 => trampoline_handler+0x43/0x60
 => __kretprobe_trampoline+0x2a/0x50
 => vfs_read+0x99/0x190
 => ksys_read+0x68/0xe0
 => do_syscall_64+0x3b/0x90
 => entry_SYSCALL_64_after_hwframe+0x44/0xae
             cat-136     [000] ...1.    14.474971: r_vfs_read_0: (ksys_read+0x68/0xe0 <- vfs_read)

This shows the double return probes (vfs_read() and full_proxy_read()) on the stack
correctly unwinded. (vfs_read() returns to 'ksys_read+0x68' and full_proxy_read()
returns to 'vfs_read+0x99')

This also changes the kretprobe behavisor a bit, now the instraction pointer in
the 'pt_regs' passed to kretprobe user handler is correctly set the real return
address. So user handlers can get it via instruction_pointer() API, and can use
stack_trace_save_regs().

You can also get this series from 
 git://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git kprobes/kretprobe-stackfix-v11


Thank you,

---

Josh Poimboeuf (3):
      objtool: Add frame-pointer-specific function ignore
      objtool: Ignore unwind hints for ignored functions
      x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline()

Masami Hiramatsu (19):
      kprobes: treewide: Cleanup the error messages for kprobes
      kprobes: Fix coding style issues
      kprobes: Use IS_ENABLED() instead of kprobes_built_in()
      kprobes: Add assertions for required lock
      kprobes: treewide: Use 'kprobe_opcode_t *' for the code address in get_optimized_kprobe()
      kprobes: Use bool type for functions which returns boolean value
      ia64: kprobes: Fix to pass correct trampoline address to the handler
      kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor()
      kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()
      kprobes: treewide: Make it harder to refer kretprobe_trampoline directly
      kprobes: Add kretprobe_find_ret_addr() for searching return address
      ARC: Add instruction_pointer_set() API
      ia64: Add instruction_pointer_set() API
      arm: kprobes: Make space for instruction pointer on stack
      kprobes: Enable stacktrace from pt_regs in kretprobe handler
      x86/kprobes: Push a fake return address at kretprobe_trampoline
      x86/unwind: Recover kretprobe trampoline entry
      tracing: Show kretprobe unknown indicator only for kretprobe_trampoline
      x86/kprobes: Fixup return address in generic trampoline handler

Punit Agrawal (5):
      kprobes: Do not use local variable when creating debugfs file
      kprobes: Use helper to parse boolean input from userspace
      kprobe: Simplify prepare_kprobe() by dropping redundant version
      csky: ftrace: Drop duplicate implementation of arch_check_ftrace_location()
      kprobes: Make arch_check_ftrace_location static


 arch/arc/include/asm/kprobes.h                |    2 
 arch/arc/include/asm/ptrace.h                 |    5 
 arch/arc/kernel/kprobes.c                     |   13 -
 arch/arm/probes/kprobes/core.c                |   15 -
 arch/arm/probes/kprobes/opt-arm.c             |    7 
 arch/arm64/include/asm/kprobes.h              |    2 
 arch/arm64/kernel/probes/kprobes.c            |   10 
 arch/arm64/kernel/probes/kprobes_trampoline.S |    4 
 arch/csky/include/asm/kprobes.h               |    2 
 arch/csky/kernel/probes/ftrace.c              |    7 
 arch/csky/kernel/probes/kprobes.c             |   14 -
 arch/csky/kernel/probes/kprobes_trampoline.S  |    4 
 arch/ia64/include/asm/ptrace.h                |    5 
 arch/ia64/kernel/kprobes.c                    |   15 -
 arch/mips/kernel/kprobes.c                    |   26 +
 arch/parisc/kernel/kprobes.c                  |    6 
 arch/powerpc/include/asm/kprobes.h            |    2 
 arch/powerpc/kernel/kprobes.c                 |   29 -
 arch/powerpc/kernel/optprobes.c               |    8 
 arch/powerpc/kernel/stacktrace.c              |    2 
 arch/riscv/include/asm/kprobes.h              |    2 
 arch/riscv/kernel/probes/kprobes.c            |   15 -
 arch/riscv/kernel/probes/kprobes_trampoline.S |    4 
 arch/s390/include/asm/kprobes.h               |    2 
 arch/s390/kernel/kprobes.c                    |   16 -
 arch/s390/kernel/stacktrace.c                 |    2 
 arch/sh/include/asm/kprobes.h                 |    2 
 arch/sh/kernel/kprobes.c                      |   12 -
 arch/sparc/include/asm/kprobes.h              |    2 
 arch/sparc/kernel/kprobes.c                   |   12 -
 arch/x86/include/asm/kprobes.h                |    1 
 arch/x86/include/asm/unwind.h                 |   23 +
 arch/x86/include/asm/unwind_hints.h           |    5 
 arch/x86/kernel/kprobes/core.c                |   71 +++-
 arch/x86/kernel/kprobes/opt.c                 |    6 
 arch/x86/kernel/unwind_frame.c                |    3 
 arch/x86/kernel/unwind_guess.c                |    3 
 arch/x86/kernel/unwind_orc.c                  |   21 +
 include/linux/kprobes.h                       |  113 ++++--
 include/linux/objtool.h                       |   12 +
 kernel/kprobes.c                              |  502 ++++++++++++++-----------
 kernel/trace/trace_kprobe.c                   |    2 
 kernel/trace/trace_output.c                   |   17 -
 lib/error-inject.c                            |    3 
 tools/include/linux/objtool.h                 |   12 +
 tools/objtool/check.c                         |    2 
 46 files changed, 607 insertions(+), 436 deletions(-)

--
Masami Hiramatsu (Linaro) <mhiramat@kernel.org>

^ permalink raw reply	[flat|nested] 76+ messages in thread

end of thread, other threads:[~2021-10-01  0:35 UTC | newest]

Thread overview: 76+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-14 14:38 [PATCH -tip v11 00/27] kprobes: Fix stacktrace with kretprobes on x86 Masami Hiramatsu
2021-09-14 14:38 ` Masami Hiramatsu
2021-09-14 14:38 ` [PATCH -tip v11 01/27] kprobes: Do not use local variable when creating debugfs file Masami Hiramatsu
2021-09-14 14:38   ` Masami Hiramatsu
2021-09-14 14:38 ` [PATCH -tip v11 02/27] kprobes: Use helper to parse boolean input from userspace Masami Hiramatsu
2021-09-14 14:38   ` Masami Hiramatsu
2021-09-14 14:38 ` [PATCH -tip v11 03/27] kprobe: Simplify prepare_kprobe() by dropping redundant version Masami Hiramatsu
2021-09-14 14:38   ` Masami Hiramatsu
2021-09-14 14:39 ` [PATCH -tip v11 04/27] csky: ftrace: Drop duplicate implementation of arch_check_ftrace_location() Masami Hiramatsu
2021-09-14 14:39   ` Masami Hiramatsu
2021-09-14 14:39 ` [PATCH -tip v11 05/27] kprobes: Make arch_check_ftrace_location static Masami Hiramatsu
2021-09-14 14:39   ` Masami Hiramatsu
2021-09-14 14:39 ` [PATCH -tip v11 06/27] kprobes: treewide: Cleanup the error messages for kprobes Masami Hiramatsu
2021-09-14 14:39   ` Masami Hiramatsu
2021-09-14 14:39 ` [PATCH -tip v11 07/27] kprobes: Fix coding style issues Masami Hiramatsu
2021-09-14 14:39   ` Masami Hiramatsu
2021-09-14 14:39 ` [PATCH -tip v11 08/27] kprobes: Use IS_ENABLED() instead of kprobes_built_in() Masami Hiramatsu
2021-09-14 14:39   ` Masami Hiramatsu
2021-09-14 14:39 ` [PATCH -tip v11 09/27] kprobes: Add assertions for required lock Masami Hiramatsu
2021-09-14 14:39   ` Masami Hiramatsu
2021-09-14 14:40 ` [PATCH -tip v11 10/27] kprobes: treewide: Use 'kprobe_opcode_t *' for the code address in get_optimized_kprobe() Masami Hiramatsu
2021-09-14 14:40   ` [PATCH -tip v11 10/27] kprobes: treewide: Use 'kprobe_opcode_t *' for the code address in get_optimi Masami Hiramatsu
2021-09-14 14:40 ` [PATCH -tip v11 11/27] kprobes: Use bool type for functions which returns boolean value Masami Hiramatsu
2021-09-14 14:40   ` Masami Hiramatsu
2021-09-14 14:40 ` [PATCH -tip v11 12/27] ia64: kprobes: Fix to pass correct trampoline address to the handler Masami Hiramatsu
2021-09-14 14:40   ` Masami Hiramatsu
2021-09-14 14:40 ` [PATCH -tip v11 13/27] kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_descriptor() Masami Hiramatsu
2021-09-14 14:40   ` [PATCH -tip v11 13/27] kprobes: treewide: Replace arch_deref_entry_point() with dereference_symbol_d Masami Hiramatsu
2021-09-14 14:40 ` [PATCH -tip v11 14/27] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler() Masami Hiramatsu
2021-09-14 14:40   ` [PATCH -tip v11 14/27] kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handle Masami Hiramatsu
2021-09-14 14:40 ` [PATCH -tip v11 15/27] kprobes: treewide: Make it harder to refer kretprobe_trampoline directly Masami Hiramatsu
2021-09-14 14:40   ` Masami Hiramatsu
2021-09-14 14:41 ` [PATCH -tip v11 16/27] kprobes: Add kretprobe_find_ret_addr() for searching return address Masami Hiramatsu
2021-09-14 14:41   ` Masami Hiramatsu
2021-09-14 14:41 ` [PATCH -tip v11 17/27] objtool: Add frame-pointer-specific function ignore Masami Hiramatsu
2021-09-14 14:41   ` Masami Hiramatsu
2021-09-14 14:41 ` [PATCH -tip v11 18/27] objtool: Ignore unwind hints for ignored functions Masami Hiramatsu
2021-09-14 14:41   ` Masami Hiramatsu
2021-09-14 14:41 ` [PATCH -tip v11 19/27] x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline() Masami Hiramatsu
2021-09-14 14:41   ` Masami Hiramatsu
2021-09-14 14:41 ` [PATCH -tip v11 20/27] ARC: Add instruction_pointer_set() API Masami Hiramatsu
2021-09-14 14:41   ` Masami Hiramatsu
2021-09-14 14:41 ` [PATCH -tip v11 21/27] ia64: " Masami Hiramatsu
2021-09-14 14:41   ` Masami Hiramatsu
2021-09-14 14:42 ` [PATCH -tip v11 22/27] arm: kprobes: Make space for instruction pointer on stack Masami Hiramatsu
2021-09-14 14:42   ` Masami Hiramatsu
2021-09-14 14:42 ` [PATCH -tip v11 23/27] kprobes: Enable stacktrace from pt_regs in kretprobe handler Masami Hiramatsu
2021-09-14 14:42   ` Masami Hiramatsu
2021-09-14 14:42 ` [PATCH -tip v11 24/27] x86/kprobes: Push a fake return address at kretprobe_trampoline Masami Hiramatsu
2021-09-14 14:42   ` Masami Hiramatsu
2021-09-14 14:42 ` [PATCH -tip v11 25/27] x86/unwind: Recover kretprobe trampoline entry Masami Hiramatsu
2021-09-14 14:42   ` Masami Hiramatsu
2021-09-14 14:42 ` [PATCH -tip v11 26/27] tracing: Show kretprobe unknown indicator only for kretprobe_trampoline Masami Hiramatsu
2021-09-14 14:42   ` Masami Hiramatsu
2021-09-14 14:42 ` [PATCH -tip v11 27/27] x86/kprobes: Fixup return address in generic trampoline handler Masami Hiramatsu
2021-09-14 14:42   ` Masami Hiramatsu
2021-09-14 22:55 ` [PATCH -tip v11 00/27] kprobes: Fix stacktrace with kretprobes on x86 Andrii Nakryiko
2021-09-14 22:55   ` Andrii Nakryiko
2021-09-29  2:24 ` Masami Hiramatsu
2021-09-29  2:24   ` Masami Hiramatsu
2021-09-30 18:17   ` Alexei Starovoitov
2021-09-30 18:17     ` Alexei Starovoitov
2021-09-30 19:34     ` Thomas Gleixner
2021-09-30 19:34       ` Thomas Gleixner
2021-09-30 21:22       ` Steven Rostedt
2021-09-30 21:22         ` Steven Rostedt
2021-09-30 23:11         ` Thomas Gleixner
2021-09-30 23:11           ` Thomas Gleixner
2021-09-30 23:27           ` Masami Hiramatsu
2021-09-30 23:27             ` Masami Hiramatsu
2021-09-30 23:37             ` Steven Rostedt
2021-09-30 23:37               ` Steven Rostedt
2021-10-01  0:35               ` Masami Hiramatsu
2021-10-01  0:35                 ` Masami Hiramatsu
2021-09-30 23:54       ` Masami Hiramatsu
2021-09-30 23:54         ` Masami Hiramatsu

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