diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2023-04-12 13:31:05 -0700 |
|---|---|---|
| committer | Josh Poimboeuf <jpoimboe@kernel.org> | 2023-05-16 06:31:50 -0700 |
| commit | 89da5a69a831f20df6463fd524e1578e12a8f46f (patch) | |
| tree | 957a55db09a6b17a3c6695ba9d2e84517055a0a2 /arch/x86/kernel/unwind_orc.c | |
| parent | dc1d05536f44cee16e46e86316e6718b2c0d8872 (diff) | |
x86/unwind/orc: Add 'unwind_debug' cmdline option
Sometimes the one-line ORC unwinder warnings aren't very helpful. Add a
new 'unwind_debug' cmdline option which will dump the full stack
contents of the current task when an error condition is encountered.
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/6afb9e48a05fd2046bfad47e69b061b43dfd0e0e.1681331449.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Diffstat (limited to 'arch/x86/kernel/unwind_orc.c')
| -rw-r--r-- | arch/x86/kernel/unwind_orc.c | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 5fbcb229f707..7891727f534e 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -13,8 +13,14 @@ #define orc_warn_current(args...) \ ({ \ - if (state->task == current && !state->error) \ + static bool dumped_before; \ + if (state->task == current && !state->error) { \ orc_warn(args); \ + if (unwind_debug && !dumped_before) { \ + dumped_before = true; \ + unwind_dump(state); \ + } \ + } \ }) extern int __start_orc_unwind_ip[]; @@ -23,8 +29,49 @@ extern struct orc_entry __start_orc_unwind[]; extern struct orc_entry __stop_orc_unwind[]; static bool orc_init __ro_after_init; +static bool unwind_debug __ro_after_init; static unsigned int lookup_num_blocks __ro_after_init; +static int __init unwind_debug_cmdline(char *str) +{ + unwind_debug = true; + + return 0; +} +early_param("unwind_debug", unwind_debug_cmdline); + +static void unwind_dump(struct unwind_state *state) +{ + static bool dumped_before; + unsigned long word, *sp; + struct stack_info stack_info = {0}; + unsigned long visit_mask = 0; + + if (dumped_before) + return; + + dumped_before = true; + + printk_deferred("unwind stack type:%d next_sp:%p mask:0x%lx graph_idx:%d\n", + state->stack_info.type, state->stack_info.next_sp, + state->stack_mask, state->graph_idx); + + for (sp = __builtin_frame_address(0); sp; + sp = PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + if (get_stack_info(sp, state->task, &stack_info, &visit_mask)) + break; + + for (; sp < stack_info.end; sp++) { + + word = READ_ONCE_NOCHECK(*sp); + + printk_deferred("%0*lx: %0*lx (%pB)\n", BITS_PER_LONG/4, + (unsigned long)sp, BITS_PER_LONG/4, + word, (void *)word); + } + } +} + static inline unsigned long orc_ip(const int *ip) { return (unsigned long)ip + *ip; |