From: peterz at infradead.org (Peter Zijlstra) Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions Date: Tue, 7 May 2019 11:27:31 +0200 [thread overview] Message-ID: <20190507092731.GH2650@hirez.programming.kicks-ass.net> (raw) In-Reply-To: <20190507085753.GO2606@hirez.programming.kicks-ass.net> On Tue, May 07, 2019 at 10:57:53AM +0200, Peter Zijlstra wrote: > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c > index 9e4fa2484d10..28d8ba3b9add 100644 > --- a/arch/x86/kernel/kprobes/core.c > +++ b/arch/x86/kernel/kprobes/core.c > @@ -731,29 +731,27 @@ asm( > ".global kretprobe_trampoline\n" > ".type kretprobe_trampoline, @function\n" > "kretprobe_trampoline:\n" > -#ifdef CONFIG_X86_64 > /* We don't bother saving the ss register */ > +#ifdef CONFIG_X86_64 > " pushq %rsp\n" > " pushfq\n" > SAVE_REGS_STRING > " movq %rsp, %rdi\n" > " call trampoline_handler\n" > /* Replace saved sp with true return address. */ > - " movq %rax, 152(%rsp)\n" > + " movq %rax, 19*8(%rsp)\n" > RESTORE_REGS_STRING > " popfq\n" > #else > - " pushf\n" > + " pushl %esp\n" > + " pushfl\n" > SAVE_REGS_STRING > " movl %esp, %eax\n" > " call trampoline_handler\n" > - /* Move flags to cs */ > - " movl 56(%esp), %edx\n" > - " movl %edx, 52(%esp)\n" > - /* Replace saved flags with true return address. */ > - " movl %eax, 56(%esp)\n" > + /* Replace saved sp with true return address. */ > + " movl %eax, 15*4(%esp)\n" > RESTORE_REGS_STRING > - " popf\n" > + " popfl\n" > #endif > " ret\n" > ".size kretprobe_trampoline, .-kretprobe_trampoline\n" > diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c > index f14262952015..c1010207d036 100644 > --- a/arch/x86/kernel/kprobes/opt.c > +++ b/arch/x86/kernel/kprobes/opt.c > @@ -115,14 +115,15 @@ asm ( > "optprobe_template_call:\n" > ASM_NOP5 > /* Move flags to rsp */ > - " movq 144(%rsp), %rdx\n" > - " movq %rdx, 152(%rsp)\n" > + " movq 18*8(%rsp), %rdx\n" > + " movq %rdx, 19*8(%rsp)\n" > RESTORE_REGS_STRING > /* Skip flags entry */ > " addq $8, %rsp\n" > " popfq\n" > #else /* CONFIG_X86_32 */ > - " pushf\n" > + " pushl %esp\n" > + " pushfl\n" > SAVE_REGS_STRING > " movl %esp, %edx\n" > ".global optprobe_template_val\n" > @@ -131,9 +132,13 @@ asm ( > ".global optprobe_template_call\n" > "optprobe_template_call:\n" > ASM_NOP5 > + /* Move flags into esp */ > + " movl 14*4(%esp), %edx\n" > + " movl %edx, 15*4(%esp)\n" > RESTORE_REGS_STRING > - " addl $4, %esp\n" /* skip cs */ > - " popf\n" > + /* Skip flags entry */ > + " addl $4, %esp\n" > + " popfl\n" > #endif > ".global optprobe_template_end\n" > "optprobe_template_end:\n" FWIW, both these trampolines assume a kprobe will not int3_emulate_{push/call}(), for both bitnesses. But then; I'm thinking kprobes should be inspection only and not modify things. So that might just be good enough.
WARNING: multiple messages have this Message-ID (diff)
From: peterz@infradead.org (Peter Zijlstra) Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions Date: Tue, 7 May 2019 11:27:31 +0200 [thread overview] Message-ID: <20190507092731.GH2650@hirez.programming.kicks-ass.net> (raw) Message-ID: <20190507092731.2JGs2-sk5DQML_6_1wn_8zTZcWKMuqHka_radPsjrRw@z> (raw) In-Reply-To: <20190507085753.GO2606@hirez.programming.kicks-ass.net> On Tue, May 07, 2019@10:57:53AM +0200, Peter Zijlstra wrote: > diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c > index 9e4fa2484d10..28d8ba3b9add 100644 > --- a/arch/x86/kernel/kprobes/core.c > +++ b/arch/x86/kernel/kprobes/core.c > @@ -731,29 +731,27 @@ asm( > ".global kretprobe_trampoline\n" > ".type kretprobe_trampoline, @function\n" > "kretprobe_trampoline:\n" > -#ifdef CONFIG_X86_64 > /* We don't bother saving the ss register */ > +#ifdef CONFIG_X86_64 > " pushq %rsp\n" > " pushfq\n" > SAVE_REGS_STRING > " movq %rsp, %rdi\n" > " call trampoline_handler\n" > /* Replace saved sp with true return address. */ > - " movq %rax, 152(%rsp)\n" > + " movq %rax, 19*8(%rsp)\n" > RESTORE_REGS_STRING > " popfq\n" > #else > - " pushf\n" > + " pushl %esp\n" > + " pushfl\n" > SAVE_REGS_STRING > " movl %esp, %eax\n" > " call trampoline_handler\n" > - /* Move flags to cs */ > - " movl 56(%esp), %edx\n" > - " movl %edx, 52(%esp)\n" > - /* Replace saved flags with true return address. */ > - " movl %eax, 56(%esp)\n" > + /* Replace saved sp with true return address. */ > + " movl %eax, 15*4(%esp)\n" > RESTORE_REGS_STRING > - " popf\n" > + " popfl\n" > #endif > " ret\n" > ".size kretprobe_trampoline, .-kretprobe_trampoline\n" > diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c > index f14262952015..c1010207d036 100644 > --- a/arch/x86/kernel/kprobes/opt.c > +++ b/arch/x86/kernel/kprobes/opt.c > @@ -115,14 +115,15 @@ asm ( > "optprobe_template_call:\n" > ASM_NOP5 > /* Move flags to rsp */ > - " movq 144(%rsp), %rdx\n" > - " movq %rdx, 152(%rsp)\n" > + " movq 18*8(%rsp), %rdx\n" > + " movq %rdx, 19*8(%rsp)\n" > RESTORE_REGS_STRING > /* Skip flags entry */ > " addq $8, %rsp\n" > " popfq\n" > #else /* CONFIG_X86_32 */ > - " pushf\n" > + " pushl %esp\n" > + " pushfl\n" > SAVE_REGS_STRING > " movl %esp, %edx\n" > ".global optprobe_template_val\n" > @@ -131,9 +132,13 @@ asm ( > ".global optprobe_template_call\n" > "optprobe_template_call:\n" > ASM_NOP5 > + /* Move flags into esp */ > + " movl 14*4(%esp), %edx\n" > + " movl %edx, 15*4(%esp)\n" > RESTORE_REGS_STRING > - " addl $4, %esp\n" /* skip cs */ > - " popf\n" > + /* Skip flags entry */ > + " addl $4, %esp\n" > + " popfl\n" > #endif > ".global optprobe_template_end\n" > "optprobe_template_end:\n" FWIW, both these trampolines assume a kprobe will not int3_emulate_{push/call}(), for both bitnesses. But then; I'm thinking kprobes should be inspection only and not modify things. So that might just be good enough.
next prev parent reply other threads:[~2019-05-07 9:27 UTC|newest] Thread overview: 204+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <20190501202830.347656894@goodmis.org> 2019-05-01 20:28 ` [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions rostedt 2019-05-01 20:28 ` Steven Rostedt 2019-05-02 3:24 ` rostedt 2019-05-02 3:24 ` Steven Rostedt 2019-05-02 16:21 ` peterz 2019-05-02 16:21 ` Peter Zijlstra 2019-05-02 16:29 ` peterz 2019-05-02 16:29 ` Peter Zijlstra 2019-05-02 18:02 ` torvalds 2019-05-02 18:02 ` Linus Torvalds 2019-05-02 18:18 ` peterz 2019-05-02 18:18 ` Peter Zijlstra 2019-05-02 18:30 ` peterz 2019-05-02 18:30 ` Peter Zijlstra 2019-05-02 18:43 ` torvalds 2019-05-02 18:43 ` Linus Torvalds 2019-05-02 19:28 ` jikos 2019-05-02 19:28 ` Jiri Kosina 2019-05-02 20:25 ` luto 2019-05-02 20:25 ` Andy Lutomirski 2019-05-02 20:21 ` peterz 2019-05-02 20:21 ` Peter Zijlstra 2019-05-02 20:49 ` torvalds 2019-05-02 20:49 ` Linus Torvalds 2019-05-02 21:32 ` peterz 2019-05-02 21:32 ` Peter Zijlstra 2019-05-03 19:24 ` rostedt 2019-05-03 19:24 ` Steven Rostedt 2019-05-03 21:46 ` torvalds 2019-05-03 21:46 ` Linus Torvalds 2019-05-03 22:49 ` rostedt 2019-05-03 22:49 ` Steven Rostedt 2019-05-03 23:07 ` torvalds 2019-05-03 23:07 ` Linus Torvalds 2019-05-04 4:17 ` rostedt 2019-05-04 4:17 ` Steven Rostedt [not found] ` <CAHk-=wiuSFbv_rELND-BLWcP0GSZ0yF=xOAEcf61GE3bU9d=yg@mail.gmail.com> 2019-05-04 18:59 ` torvalds 2019-05-04 18:59 ` Linus Torvalds 2019-05-04 20:12 ` luto 2019-05-04 20:12 ` Andy Lutomirski 2019-05-04 20:28 ` torvalds 2019-05-04 20:28 ` Linus Torvalds 2019-05-04 20:36 ` torvalds 2019-05-04 20:36 ` Linus Torvalds 2019-05-03 22:55 ` luto 2019-05-03 22:55 ` Andy Lutomirski 2019-05-03 23:16 ` torvalds 2019-05-03 23:16 ` Linus Torvalds 2019-05-03 23:32 ` luto 2019-05-03 23:32 ` Andy Lutomirski 2019-05-02 22:52 ` rostedt 2019-05-02 22:52 ` Steven Rostedt 2019-05-02 23:31 ` rostedt 2019-05-02 23:31 ` Steven Rostedt 2019-05-02 23:50 ` rostedt 2019-05-02 23:50 ` Steven Rostedt 2019-05-03 1:51 ` [RFC][PATCH 1/2 v2] " rostedt 2019-05-03 1:51 ` Steven Rostedt 2019-05-03 9:29 ` [RFC][PATCH 1/2] " peterz 2019-05-03 9:29 ` Peter Zijlstra 2019-05-03 13:22 ` rostedt 2019-05-03 13:22 ` Steven Rostedt 2019-05-03 16:20 ` luto 2019-05-03 16:20 ` Andy Lutomirski 2019-05-03 16:31 ` rostedt 2019-05-03 16:31 ` Steven Rostedt 2019-05-03 16:35 ` peterz 2019-05-03 16:35 ` Peter Zijlstra 2019-05-03 16:44 ` luto 2019-05-03 16:44 ` Andy Lutomirski 2019-05-03 16:49 ` rostedt 2019-05-03 16:49 ` Steven Rostedt 2019-05-03 16:32 ` peterz 2019-05-03 16:32 ` Peter Zijlstra 2019-05-03 18:57 ` torvalds 2019-05-03 18:57 ` Linus Torvalds 2019-05-06 8:19 ` peterz 2019-05-06 8:19 ` Peter Zijlstra 2019-05-06 13:56 ` rostedt 2019-05-06 13:56 ` Steven Rostedt 2019-05-06 16:17 ` torvalds 2019-05-06 16:17 ` Linus Torvalds 2019-05-06 16:19 ` torvalds 2019-05-06 16:19 ` Linus Torvalds 2019-05-06 17:06 ` rostedt 2019-05-06 17:06 ` Steven Rostedt 2019-05-06 18:06 ` torvalds 2019-05-06 18:06 ` Linus Torvalds 2019-05-06 18:57 ` rostedt 2019-05-06 18:57 ` Steven Rostedt 2019-05-06 19:46 ` torvalds 2019-05-06 19:46 ` Linus Torvalds 2019-05-06 20:29 ` rostedt 2019-05-06 20:29 ` Steven Rostedt 2019-05-06 20:42 ` torvalds 2019-05-06 20:42 ` Linus Torvalds 2019-05-06 20:44 ` torvalds 2019-05-06 20:44 ` Linus Torvalds 2019-05-06 21:45 ` rostedt 2019-05-06 21:45 ` Steven Rostedt 2019-05-06 22:06 ` torvalds 2019-05-06 22:06 ` Linus Torvalds 2019-05-06 22:31 ` torvalds 2019-05-06 22:31 ` Linus Torvalds 2019-05-07 0:10 ` rostedt 2019-05-07 0:10 ` Steven Rostedt 2019-05-07 1:06 ` torvalds 2019-05-07 1:06 ` Linus Torvalds 2019-05-07 1:04 ` rostedt 2019-05-07 1:04 ` Steven Rostedt 2019-05-07 1:34 ` rostedt 2019-05-07 1:34 ` Steven Rostedt 2019-05-07 1:34 ` torvalds 2019-05-07 1:34 ` Linus Torvalds 2019-05-07 1:53 ` rostedt 2019-05-07 1:53 ` Steven Rostedt 2019-05-07 2:22 ` torvalds 2019-05-07 2:22 ` Linus Torvalds 2019-05-07 2:58 ` rostedt 2019-05-07 2:58 ` Steven Rostedt 2019-05-07 3:05 ` torvalds 2019-05-07 3:05 ` Linus Torvalds 2019-05-07 3:21 ` rostedt 2019-05-07 3:21 ` Steven Rostedt 2019-05-07 3:28 ` torvalds 2019-05-07 3:28 ` Linus Torvalds 2019-05-07 14:54 ` torvalds 2019-05-07 14:54 ` Linus Torvalds 2019-05-07 15:12 ` rostedt 2019-05-07 15:12 ` Steven Rostedt 2019-05-07 15:25 ` rostedt 2019-05-07 15:25 ` Steven Rostedt 2019-05-07 16:25 ` rostedt 2019-05-07 16:25 ` Steven Rostedt 2019-05-07 15:31 ` torvalds 2019-05-07 15:31 ` Linus Torvalds 2019-05-07 15:45 ` rostedt 2019-05-07 15:45 ` Steven Rostedt 2019-05-07 16:34 ` peterz 2019-05-07 16:34 ` Peter Zijlstra 2019-05-07 17:08 ` torvalds 2019-05-07 17:08 ` Linus Torvalds 2019-05-07 17:21 ` jpoimboe 2019-05-07 17:21 ` Josh Poimboeuf 2019-05-07 21:24 ` rostedt 2019-05-07 21:24 ` Steven Rostedt 2019-05-08 4:50 ` torvalds 2019-05-08 4:50 ` Linus Torvalds 2019-05-08 16:37 ` rostedt 2019-05-08 16:37 ` Steven Rostedt 2019-05-07 17:38 ` peterz 2019-05-07 17:38 ` Peter Zijlstra 2019-05-07 9:51 ` peterz 2019-05-07 9:51 ` Peter Zijlstra 2019-05-07 14:48 ` luto 2019-05-07 14:48 ` Andy Lutomirski 2019-05-07 14:57 ` torvalds 2019-05-07 14:57 ` Linus Torvalds 2019-05-07 14:13 ` mhiramat 2019-05-07 14:13 ` Masami Hiramatsu 2019-05-07 17:15 ` mhiramat 2019-05-07 17:15 ` Masami Hiramatsu 2019-05-06 14:22 ` peterz 2019-05-06 14:22 ` Peter Zijlstra 2019-05-07 8:57 ` peterz 2019-05-07 8:57 ` Peter Zijlstra 2019-05-07 9:18 ` David.Laight 2019-05-07 9:18 ` David Laight 2019-05-07 11:30 ` peterz 2019-05-07 11:30 ` Peter Zijlstra 2019-05-07 12:57 ` David.Laight 2019-05-07 12:57 ` David Laight 2019-05-07 13:14 ` rostedt 2019-05-07 13:14 ` Steven Rostedt 2019-05-07 14:50 ` David.Laight 2019-05-07 14:50 ` David Laight 2019-05-07 14:57 ` rostedt 2019-05-07 14:57 ` Steven Rostedt 2019-05-07 15:46 ` David.Laight 2019-05-07 15:46 ` David Laight 2019-05-07 13:32 ` peterz 2019-05-07 13:32 ` Peter Zijlstra 2019-05-07 9:27 ` peterz [this message] 2019-05-07 9:27 ` Peter Zijlstra 2019-05-07 12:27 ` rostedt 2019-05-07 12:27 ` Steven Rostedt 2019-05-07 12:41 ` peterz 2019-05-07 12:41 ` Peter Zijlstra 2019-05-07 12:54 ` rostedt 2019-05-07 12:54 ` Steven Rostedt 2019-05-07 17:22 ` masami.hiramatsu 2019-05-07 17:22 ` Masami Hiramatsu 2019-05-07 14:28 ` peterz 2019-05-07 14:28 ` Peter Zijlstra 2019-05-02 20:48 ` rostedt 2019-05-02 20:48 ` Steven Rostedt 2019-05-06 15:14 ` jpoimboe 2019-05-06 15:14 ` Josh Poimboeuf 2019-05-01 20:28 ` [RFC][PATCH 2/2] ftrace/x86: Emulate call function while updating in breakpoint handler rostedt 2019-05-01 20:28 ` Steven Rostedt 2019-05-03 10:22 ` [RFC][PATCH 1.5/2] x86: Add int3_emulate_call() selftest peterz 2019-05-03 10:22 ` Peter Zijlstra 2019-05-03 18:46 ` rostedt 2019-05-03 18:46 ` Steven Rostedt
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