signals: demultiplexing SIGTRAP signal

Currently a SIGTRAP can denote any one of below reasons.
	- Breakpoint hit
	- H/W debug register hit
	- Single step
	- 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>
Cc: Roland McGrath <roland@redhat.com>
Cc: akpm@linux-foundation.org
Cc: paulus@samba.org
Cc: linuxppc-dev@ozlabs.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Srinivasa Ds 2008-09-23 15:23:52 +05:30 committed by Ingo Molnar
parent 101d5b7137
commit da654b74bd
9 changed files with 21 additions and 21 deletions

View file

@ -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

View file

@ -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

View file

@ -1358,7 +1358,8 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
#endif
}
void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
int error_code, int si_code)
{
struct siginfo info;
@ -1367,7 +1368,7 @@ void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
memset(&info, 0, sizeof(info));
info.si_signo = SIGTRAP;
info.si_code = TRAP_BRKPT;
info.si_code = si_code;
/* User-mode ip? */
info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
@ -1454,5 +1455,5 @@ asmregparm void syscall_trace_leave(struct pt_regs *regs)
*/
if (test_thread_flag(TIF_SINGLESTEP) &&
tracehook_consider_fatal_signal(current, SIGTRAP, SIG_DFL))
send_sigtrap(current, regs, 0);
send_sigtrap(current, regs, 0, TRAP_BRKPT);
}

View file

@ -891,6 +891,7 @@ void __kprobes do_debug(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk = current;
unsigned int condition;
int si_code;
trace_hardirqs_fixup();
@ -935,8 +936,9 @@ void __kprobes do_debug(struct pt_regs *regs, long error_code)
goto clear_TF_reenable;
}
si_code = get_si_code((unsigned long)condition);
/* Ok, finally something we can handle */
send_sigtrap(tsk, regs, error_code);
send_sigtrap(tsk, regs, error_code, si_code);
/*
* Disable additional traps. They'll be re-enabled when

View file

@ -941,7 +941,7 @@ asmlinkage void __kprobes do_debug(struct pt_regs *regs,
tsk->thread.error_code = error_code;
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_BRKPT;
info.si_code = get_si_code(condition);
info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
force_sig_info(SIGTRAP, &info, tsk);

View file

@ -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/watchpoint */
#define NSIGTRAP 2
/*

View file

@ -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

View file

@ -143,7 +143,7 @@ convert_ip_to_linear(struct task_struct *child, struct pt_regs *regs);
#ifdef CONFIG_X86_32
extern void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
int error_code);
int error_code, int si_code);
#endif
void signal_fault(struct pt_regs *regs, void __user *frame, char *where);

View file

@ -36,6 +36,16 @@ void do_invalid_op(struct pt_regs *, long);
void do_general_protection(struct pt_regs *, long);
void do_nmi(struct pt_regs *, long);
static inline int get_si_code(unsigned long condition)
{
if (condition & DR_STEP)
return TRAP_TRACE;
else if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3))
return TRAP_HWBKPT;
else
return TRAP_BRKPT;
}
extern int panic_on_unrecovered_nmi;
extern int kstack_depth_to_print;