diff options
| -rw-r--r-- | arch/sparc/kernel/signal32.c | 18 | ||||
| -rw-r--r-- | arch/sparc/kernel/signal_32.c | 30 | ||||
| -rw-r--r-- | arch/sparc/kernel/signal_64.c | 42 |
3 files changed, 63 insertions, 27 deletions
diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c index 5d92488..2e58328 100644 --- a/arch/sparc/kernel/signal32.c +++ b/arch/sparc/kernel/signal32.c @@ -829,21 +829,23 @@ static inline void syscall_restart32(unsigned long orig_i0, struct pt_regs *regs * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. */ -void do_signal32(sigset_t *oldset, struct pt_regs * regs, - int restart_syscall, unsigned long orig_i0) +void do_signal32(sigset_t *oldset, struct pt_regs * regs) { struct k_sigaction ka; + unsigned long orig_i0; + int restart_syscall; siginfo_t info; int signr; signr = get_signal_to_deliver(&info, &ka, regs, NULL); - /* If the debugger messes with the program counter, it clears - * the "in syscall" bit, directing us to not perform a syscall - * restart. - */ - if (restart_syscall && !pt_regs_is_syscall(regs)) - restart_syscall = 0; + restart_syscall = 0; + orig_i0 = 0; + if (pt_regs_is_syscall(regs) && + (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) { + restart_syscall = 1; + orig_i0 = regs->u_regs[UREG_G6]; + } if (signr > 0) { if (restart_syscall) diff --git a/arch/sparc/kernel/signal_32.c b/arch/sparc/kernel/signal_32.c index 04ede8f..2302567 100644 --- a/arch/sparc/kernel/signal_32.c +++ b/arch/sparc/kernel/signal_32.c @@ -525,10 +525,26 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0) siginfo_t info; int signr; + /* It's a lot of work and synchronization to add a new ptrace + * register for GDB to save and restore in order to get + * orig_i0 correct for syscall restarts when debugging. + * + * Although it should be the case that most of the global + * registers are volatile across a system call, glibc already + * depends upon that fact that we preserve them. So we can't + * just use any global register to save away the orig_i0 value. + * + * In particular %g2, %g3, %g4, and %g5 are all assumed to be + * preserved across a system call trap by various pieces of + * code in glibc. + * + * %g7 is used as the "thread register". %g6 is not used in + * any fixed manner. %g6 is used as a scratch register and + * a compiler temporary, but it's value is never used across + * a system call. Therefore %g6 is usable for orig_i0 storage. + */ if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) - restart_syscall = 1; - else - restart_syscall = 0; + regs->u_regs[UREG_G6] = orig_i0; if (test_thread_flag(TIF_RESTORE_SIGMASK)) oldset = ¤t->saved_sigmask; @@ -541,8 +557,12 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0) * the software "in syscall" bit, directing us to not perform * a syscall restart. */ - if (restart_syscall && !pt_regs_is_syscall(regs)) - restart_syscall = 0; + restart_syscall = 0; + if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) { + restart_syscall = 1; + orig_i0 = regs->u_regs[UREG_G6]; + } + if (signr > 0) { if (restart_syscall) diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c index 47509df..d58260b 100644 --- a/arch/sparc/kernel/signal_64.c +++ b/arch/sparc/kernel/signal_64.c @@ -535,11 +535,27 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0) siginfo_t info; int signr; + /* It's a lot of work and synchronization to add a new ptrace + * register for GDB to save and restore in order to get + * orig_i0 correct for syscall restarts when debugging. + * + * Although it should be the case that most of the global + * registers are volatile across a system call, glibc already + * depends upon that fact that we preserve them. So we can't + * just use any global register to save away the orig_i0 value. + * + * In particular %g2, %g3, %g4, and %g5 are all assumed to be + * preserved across a system call trap by various pieces of + * code in glibc. + * + * %g7 is used as the "thread register". %g6 is not used in + * any fixed manner. %g6 is used as a scratch register and + * a compiler temporary, but it's value is never used across + * a system call. Therefore %g6 is usable for orig_i0 storage. + */ if (pt_regs_is_syscall(regs) && - (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) { - restart_syscall = 1; - } else - restart_syscall = 0; + (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) + regs->u_regs[UREG_G6] = orig_i0; if (current_thread_info()->status & TS_RESTORE_SIGMASK) oldset = ¤t->saved_sigmask; @@ -548,22 +564,20 @@ static void do_signal(struct pt_regs *regs, unsigned long orig_i0) #ifdef CONFIG_COMPAT if (test_thread_flag(TIF_32BIT)) { - extern void do_signal32(sigset_t *, struct pt_regs *, - int restart_syscall, - unsigned long orig_i0); - do_signal32(oldset, regs, restart_syscall, orig_i0); + extern void do_signal32(sigset_t *, struct pt_regs *); + do_signal32(oldset, regs); return; } #endif signr = get_signal_to_deliver(&info, &ka, regs, NULL); - /* If the debugger messes with the program counter, it clears - * the software "in syscall" bit, directing us to not perform - * a syscall restart. - */ - if (restart_syscall && !pt_regs_is_syscall(regs)) - restart_syscall = 0; + restart_syscall = 0; + if (pt_regs_is_syscall(regs) && + (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) { + restart_syscall = 1; + orig_i0 = regs->u_regs[UREG_G6]; + } if (signr > 0) { if (restart_syscall) |