Messages in this thread Patch in this message | | | Date | Fri, 21 Oct 2016 00:51:48 -0700 | From | tip-bot for Josh Poimboeuf <> | Subject | [tip:x86/asm] x86/dumpstack: Print orig_ax in __show_regs() |
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Commit-ID: 6fa81a12b3f1834a22167aa2d7b24dcc4bf884e3 Gitweb: http://git.kernel.org/tip/6fa81a12b3f1834a22167aa2d7b24dcc4bf884e3 Author: Josh Poimboeuf <jpoimboe@redhat.com> AuthorDate: Thu, 20 Oct 2016 11:34:45 -0500 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Fri, 21 Oct 2016 09:26:05 +0200
x86/dumpstack: Print orig_ax in __show_regs()
The value of regs->orig_ax contains potentially useful debugging data: For syscalls it contains the syscall number. For interrupts it contains the (negated) vector number. To reduce noise, print it only if it has a useful value (i.e., something other than -1).
Here's what it looks like for a write syscall:
RIP: 0033:[<00007f53ad7b1940>] 0x7f53ad7b1940 RSP: 002b:00007fff8de66558 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007f53ad7b1940 RDX: 0000000000000002 RSI: 00007f53ae0ca000 RDI: 0000000000000001 ...
Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/93f0fe0307a4af884d3fca00edabcc8cff236002.1476973742.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/process_64.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index b3b50ac..f1c36da 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -63,8 +63,13 @@ void __show_regs(struct pt_regs *regs, int all) printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] %pS\n", regs->cs & 0xffff, regs->ip, (void *)regs->ip); - printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, + printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx", regs->ss, regs->sp, regs->flags); + if (regs->orig_ax != -1) + pr_cont(" ORIG_RAX: %016lx\n", regs->orig_ax); + else + pr_cont("\n"); + printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n", regs->ax, regs->bx, regs->cx); printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n",
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