| Message ID | 200809221602.32616.srinivasa@in.ibm.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
* Srinivasa Ds <srinivasa@in.ibm.com> wrote: > Currently a SIGTRAP signal can denote any one of below reasons. > - Breakpoint hit > - H/W debug register hit > - Single step > - SIGTRAP signal sent through kill() or rasie() > > Architectures like powerpc/parisc provides infrastructure to > demultiplex SIGTRAP signal by passing down the information for > receiving SIGTRAP through si_code of siginfot_t structure. Here is an > attempt is generalise this infrastructure by extending it to x86 and > x86_64 archs. no fundamental objections - assuming existing x86 apps have not grown an ABI dependency on the existing send_sigtrap() semantics. (Debuggers and JITs would be a candidate for such dependencies.) a small implementational detail, this bit: > @@ -935,8 +936,22 @@ void __kprobes do_debug(struct pt_regs * > goto clear_TF_reenable; > } > > - /* Ok, finally something we can handle */ > - send_sigtrap(tsk, regs, error_code); > + tsk->thread.trap_no = 1; > + tsk->thread.error_code = error_code; > + > + memset(&info, 0, sizeof(info)); > + info.si_signo = SIGTRAP; > + if (condition & DR_STEP) > + info.si_code = TRAP_TRACE; > + else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) > + info.si_code = TRAP_HWBKPT; > + else > + info.si_code = TRAP_BRKPT; > + /* User-mode ip? */ > + info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL; > + > + /* Send us the fake SIGTRAP */ > + force_sig_info(SIGTRAP, &info, tsk); should be pushed into [a sufficiently extended] send_sigtrap() instead. and this bit: > - info.si_code = TRAP_BRKPT; > + if (condition & DR_STEP) > + info.si_code = TRAP_TRACE; > + else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) > + info.si_code = TRAP_HWBKPT; > + else > + info.si_code = TRAP_BRKPT; should be separated into a helper function as well i guess. Roland, any objections to the core idea (or to the implementation)? Ingo
Index: linux-2.6.27-rc7/arch/ia64/include/asm/siginfo.h =================================================================== --- linux-2.6.27-rc7.orig/arch/ia64/include/asm/siginfo.h +++ linux-2.6.27-rc7/arch/ia64/include/asm/siginfo.h @@ -113,11 +113,6 @@ typedef struct siginfo { #undef NSIGSEGV #define NSIGSEGV 3 -/* - * SIGTRAP si_codes - */ -#define TRAP_BRANCH (__SI_FAULT|3) /* process taken branch trap */ -#define TRAP_HWBKPT (__SI_FAULT|4) /* hardware breakpoint or watchpoint */ #undef NSIGTRAP #define NSIGTRAP 4 Index: linux-2.6.27-rc7/arch/powerpc/include/asm/siginfo.h =================================================================== --- linux-2.6.27-rc7.orig/arch/powerpc/include/asm/siginfo.h +++ linux-2.6.27-rc7/arch/powerpc/include/asm/siginfo.h @@ -15,11 +15,6 @@ #include <asm-generic/siginfo.h> -/* - * SIGTRAP si_codes - */ -#define TRAP_BRANCH (__SI_FAULT|3) /* process taken branch trap */ -#define TRAP_HWBKPT (__SI_FAULT|4) /* hardware breakpoint or watchpoint */ #undef NSIGTRAP #define NSIGTRAP 4 Index: linux-2.6.27-rc7/arch/x86/kernel/traps_32.c =================================================================== --- linux-2.6.27-rc7.orig/arch/x86/kernel/traps_32.c +++ linux-2.6.27-rc7/arch/x86/kernel/traps_32.c @@ -890,6 +890,7 @@ void __kprobes do_int3(struct pt_regs *r void __kprobes do_debug(struct pt_regs *regs, long error_code) { struct task_struct *tsk = current; + struct siginfo info; unsigned int condition; trace_hardirqs_fixup(); @@ -935,8 +936,22 @@ void __kprobes do_debug(struct pt_regs * goto clear_TF_reenable; } - /* Ok, finally something we can handle */ - send_sigtrap(tsk, regs, error_code); + tsk->thread.trap_no = 1; + tsk->thread.error_code = error_code; + + memset(&info, 0, sizeof(info)); + info.si_signo = SIGTRAP; + if (condition & DR_STEP) + info.si_code = TRAP_TRACE; + else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) + info.si_code = TRAP_HWBKPT; + else + info.si_code = TRAP_BRKPT; + /* User-mode ip? */ + info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL; + + /* Send us the fake SIGTRAP */ + force_sig_info(SIGTRAP, &info, tsk); /* * Disable additional traps. They'll be re-enabled when Index: linux-2.6.27-rc7/arch/x86/kernel/traps_64.c =================================================================== --- linux-2.6.27-rc7.orig/arch/x86/kernel/traps_64.c +++ linux-2.6.27-rc7/arch/x86/kernel/traps_64.c @@ -936,7 +936,12 @@ asmlinkage void __kprobes do_debug(struc tsk->thread.error_code = error_code; info.si_signo = SIGTRAP; info.si_errno = 0; - info.si_code = TRAP_BRKPT; + if (condition & DR_STEP) + info.si_code = TRAP_TRACE; + else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) + info.si_code = TRAP_HWBKPT; + else + info.si_code = TRAP_BRKPT; info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL; force_sig_info(SIGTRAP, &info, tsk); Index: linux-2.6.27-rc7/include/asm-generic/siginfo.h =================================================================== --- linux-2.6.27-rc7.orig/include/asm-generic/siginfo.h +++ linux-2.6.27-rc7/include/asm-generic/siginfo.h @@ -199,6 +199,8 @@ typedef struct siginfo { */ #define TRAP_BRKPT (__SI_FAULT|1) /* process breakpoint */ #define TRAP_TRACE (__SI_FAULT|2) /* process trace trap */ +#define TRAP_BRANCH (__SI_FAULT|3) /* process taken branch trap */ +#define TRAP_HWBKPT (__SI_FAULT|4) /* hardware breakpoint or watchpoint */ #define NSIGTRAP 2 /* Index: linux-2.6.27-rc7/include/asm-parisc/siginfo.h =================================================================== --- linux-2.6.27-rc7.orig/include/asm-parisc/siginfo.h +++ linux-2.6.27-rc7/include/asm-parisc/siginfo.h @@ -3,11 +3,6 @@ #include <asm-generic/siginfo.h> -/* - * SIGTRAP si_codes - */ -#define TRAP_BRANCH (__SI_FAULT|3) /* process taken branch trap */ -#define TRAP_HWBKPT (__SI_FAULT|4) /* hardware breakpoint or watchpoint */ #undef NSIGTRAP #define NSIGTRAP 4
Currently a SIGTRAP signal can denote any one of below reasons. - Breakpoint hit - H/W debug register hit - Single step - SIGTRAP signal sent through kill() or rasie() Architectures like powerpc/parisc provides infrastructure to demultiplex SIGTRAP signal by passing down the information for receiving SIGTRAP through si_code of siginfot_t structure. Here is an attempt is generalise this infrastructure by extending it to x86 and x86_64 archs. Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> --- arch/ia64/include/asm/siginfo.h | 5 ----- arch/powerpc/include/asm/siginfo.h | 5 ----- arch/x86/kernel/traps_32.c | 19 +++++++++++++++++-- arch/x86/kernel/traps_64.c | 7 ++++++- include/asm-generic/siginfo.h | 2 ++ include/asm-parisc/siginfo.h | 5 ----- 6 files changed, 25 insertions(+), 18 deletions(-)