(yet another) kprobes x86 code unification and boosters
cover (yet another) kprobes x86 code unification and boosters
Hello all,
I developed a series of patches which unifies kprobes code on x86
and introduces boosters on x86-64. These patches can be applied to 2.6.24-rc4-mm1.
The purpose of this patchset is unifying kprobes_[32|64].[c|h] to kprobes.[c|h] for simplifying code maintenance.
I know these patches are conflicting with Harvey's patch. We need to solve that.
kprobe-booster and kretprobe-booster were explained in:
http://marc.info/?l=linux-kernel&m=113862526017068&w=2
Currently, these patches do unification as following order.
1. Clean up and fix bugs in kprobes[1/6, 2/6].
2. Introduce kprobe-booster and kretprobe-booster for x86-64[3/6, 4/6]. (x86-32 kprobes already has same functionalities)
3. Prepare unification[5/6].
4. Unify kprobes code[6/6].
If you have any comment, please let me know.
Best Regards,
Signature · 7 lines
Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: [email protected], [email protected]
Quoted 11 lines · Masami Hiramatsu
Hello all,
I developed a series of patches which unifies kprobes code on x86 and introduces boosters on x86-64. These patches can be applied to 2.6.24-rc4-mm1.
The purpose of this patchset is unifying kprobes_[32|64].[c|h] to kprobes.[c|h] for simplifying code maintenance.
I know these patches are conflicting with Harvey's patch. We need to solve that.
your series fixes the 64-bit crash that i was seeing, so i've picked it up. Please work it out with Harvey which cleanups of him are not included yet.
Ingo
Quoted 11 lines · Ingo Molnar
Quoted 9 lines · Masami Hiramatsu
Hello all,
I developed a series of patches which unifies kprobes code on x86 and introduces boosters on x86-64. These patches can be applied to 2.6.24-rc4-mm1.
The purpose of this patchset is unifying kprobes_[32|64].[c|h] to kprobes.[c|h] for simplifying code maintenance.
Quoted 7 lines
Quoted 2 lines
I know these patches are conflicting with Harvey's patch. We need to solve that.
your series fixes the 64-bit crash that i was seeing, so i've picked it up. Please work it out with Harvey which cleanups of him are not included yet.
I thought the jprobe_saved_sp looked fishy on X86_64 in my unified set but I went bug-for-bug compatible I guess :-) If you look at my cleaned up set this was one of the main source of remaining ifdefs.
Harvey
Hi,
Quoted 11 lines · Ingo Molnar
Quoted 9 lines · Masami Hiramatsu
Hello all,
I developed a series of patches which unifies kprobes code on x86 and introduces boosters on x86-64. These patches can be applied to 2.6.24-rc4-mm1.
The purpose of this patchset is unifying kprobes_[32|64].[c|h] to kprobes.[c|h] for simplifying code maintenance.
Quoted 6 lines
Quoted 2 lines
I know these patches are conflicting with Harvey's patch. We need to solve that.
your series fixes the 64-bit crash that i was seeing, so i've picked it up. Please work it out with Harvey which cleanups of him are not included yet.
Absolutely sure.
I compared my patch and Harvey's.
These directions are almost same.
Harvey, I have found some differences and I'd like to fix that with you. I think following comments and style cleanups in your patch are good to me.
Quoted 30 lines
(quoted diff) +3
-3@@ -156,7 +157,7 @@ twobyte_has_modrm[256 / sizeof(unsigned long)] = { #undef RF /* insert a jmp code */ -static __always_inline void set_jmp_op(void *from, void *to) +static inline void set_jmp_op(void *from, void *to) { struct __arch_jmp_op { char op;@@ -170,7 +171,7 @@ static __always_inline void set_jmp_op(void *from, void *to) /* * returns non-zero if opcodes can be boosted. */ -static __always_inline int can_boost(kprobe_opcode_t *opcodes) +static inline int can_boost(kprobe_opcode_t *opcodes) { kprobe_opcode_t opcode; kprobe_opcode_t *orig_opcodes = opcodes;@@ -734,7 +740,7 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) regs->flags |= kcb->kprobe_saved_flags; trace_hardirqs_fixup_flags(regs->flags); - /*Restore back the original saved kprobes variables and continue. */ + /* Restore the original saved kprobes variables and continue. */ if (kcb->kprobe_status == KPROBE_REENTER) { restore_previous_kprobe(kcb); goto out;
Review int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) · line 872
Quoted 8 lines
(quoted diff) +1
-1@@ -860,7 +866,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) addr = (unsigned long)(kcb->jprobe_saved_sp); /* - * TBD: As Linus pointed out, gcc assumes that the callee + * As Linus pointed out, gcc assumes that the callee * owns the argument space and could overwrite it, e.g. * tailcall optimization. So, to be absolutely safe * we also save and restore enough stack bytes to cover
And also, if you can unify x86/mm/extable_*.c and introduce fixup_exception() to 64-bit, it is very helpful to remove ifdefs from kprobe_fault_handler().
Thank you,
Signature · 7 lines
Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: [email protected], [email protected]