Messages in this thread Patch in this message | | | Date | Wed, 9 Aug 2006 15:13:11 +0530 | From | Ananth N Mavinakayanahalli <> | Subject | Re: [PATCH 2/3] Kprobes: Define retval helper |
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On Tue, Aug 08, 2006 at 05:25:59PM +0100, Christoph Hellwig wrote: > On Mon, Aug 07, 2006 at 05:30:24PM +0530, Ananth N Mavinakayanahalli wrote: > > From: Ananth N Mavinakayanahalli <ananth@in.ibm.com> > > > > Add the KPROBE_RETVAL macro to help extract the return value on > > different architectures, while using function-return probes. > > Good idea. You should add parentheses around regs, otherwise the C > preprocessor might bite users. Also the shouting name is quite ugly. > In fact it should probably go to asm/system.h or similar and not have > a kprobes name - it just extracts the return value from a struct pt_regs > after all.
Done! How does this look? I added it to asm/ptrace.h so it lives along with the instruction_pointer() definition.
Ananth
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Add the "get_retval" macro that just extracts the return value given the pt_regs. Useful in situations such as while using function-return probes.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
--- include/asm-i386/ptrace.h | 3 +++ include/asm-ia64/ptrace.h | 3 +++ include/asm-powerpc/ptrace.h | 2 ++ include/asm-x86_64/ptrace.h | 2 ++ 4 files changed, 10 insertions(+)
Index: linux-2.6.18-rc3/include/asm-i386/ptrace.h =================================================================== --- linux-2.6.18-rc3.orig/include/asm-i386/ptrace.h +++ linux-2.6.18-rc3/include/asm-i386/ptrace.h @@ -79,7 +79,10 @@ static inline int user_mode_vm(struct pt { return ((regs->xcs & 3) | (regs->eflags & VM_MASK)) != 0; } + #define instruction_pointer(regs) ((regs)->eip) +#define get_retval(regs) ((regs)->eax) + #if defined(CONFIG_SMP) && defined(CONFIG_FRAME_POINTER) extern unsigned long profile_pc(struct pt_regs *regs); #else Index: linux-2.6.18-rc3/include/asm-ia64/ptrace.h =================================================================== --- linux-2.6.18-rc3.orig/include/asm-ia64/ptrace.h +++ linux-2.6.18-rc3/include/asm-ia64/ptrace.h @@ -237,6 +237,9 @@ struct switch_stack { * the canonical representation by adding to instruction pointer. */ # define instruction_pointer(regs) ((regs)->cr_iip + ia64_psr(regs)->ri) + +#define get_retval(regs) ((regs)->r8) + /* Conserve space in histogram by encoding slot bits in address * bits 2 and 3 rather than bits 0 and 1. */ Index: linux-2.6.18-rc3/include/asm-powerpc/ptrace.h =================================================================== --- linux-2.6.18-rc3.orig/include/asm-powerpc/ptrace.h +++ linux-2.6.18-rc3/include/asm-powerpc/ptrace.h @@ -73,6 +73,8 @@ struct pt_regs { #ifndef __ASSEMBLY__ #define instruction_pointer(regs) ((regs)->nip) +#define get_retval(regs) ((regs)->gpr[3]) + #ifdef CONFIG_SMP extern unsigned long profile_pc(struct pt_regs *regs); #else Index: linux-2.6.18-rc3/include/asm-x86_64/ptrace.h =================================================================== --- linux-2.6.18-rc3.orig/include/asm-x86_64/ptrace.h +++ linux-2.6.18-rc3/include/asm-x86_64/ptrace.h @@ -84,6 +84,8 @@ struct pt_regs { #define user_mode(regs) (!!((regs)->cs & 3)) #define user_mode_vm(regs) user_mode(regs) #define instruction_pointer(regs) ((regs)->rip) +#define get_retval(regs) ((regs)->rax) + extern unsigned long profile_pc(struct pt_regs *regs); void signal_fault(struct pt_regs *regs, void __user *frame, char *where); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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