diff options
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/traps_32.c | 30 | ||||
| -rw-r--r-- | arch/x86/kernel/traps_64.c | 17 |
2 files changed, 30 insertions, 17 deletions
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c index 7eb1203c909..953172af6e5 100644 --- a/arch/x86/kernel/traps_32.c +++ b/arch/x86/kernel/traps_32.c @@ -88,6 +88,20 @@ static inline void conditional_sti(struct pt_regs *regs) local_irq_enable(); } +static inline void preempt_conditional_sti(struct pt_regs *regs) +{ + inc_preempt_count(); + if (regs->flags & X86_EFLAGS_IF) + local_irq_enable(); +} + +static inline void preempt_conditional_cli(struct pt_regs *regs) +{ + if (regs->flags & X86_EFLAGS_IF) + local_irq_disable(); + dec_preempt_count(); +} + static inline void die_if_kernel(const char *str, struct pt_regs *regs, long err) { @@ -498,7 +512,7 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) { struct task_struct *tsk = current; - unsigned int condition; + unsigned long condition; int si_code; get_debugreg(condition, 6); @@ -512,9 +526,9 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, SIGTRAP) == NOTIFY_STOP) return; + /* It's safe to allow irq's after DR6 has been saved */ - if (regs->flags & X86_EFLAGS_IF) - local_irq_enable(); + preempt_conditional_sti(regs); /* Mask out spurious debug traps due to lazy DR7 setting */ if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { @@ -533,16 +547,11 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) * kernel space (but re-enable TF when returning to user mode). */ if (condition & DR_STEP) { - /* - * We already checked v86 mode above, so we can - * check for kernel mode by just checking the CPL - * of CS. - */ if (!user_mode(regs)) goto clear_TF_reenable; } - si_code = get_si_code((unsigned long)condition); + si_code = get_si_code(condition); /* Ok, finally something we can handle */ send_sigtrap(tsk, regs, error_code, si_code); @@ -552,15 +561,18 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) */ clear_dr7: set_debugreg(0, 7); + preempt_conditional_cli(regs); return; debug_vm86: handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1); + preempt_conditional_cli(regs); return; clear_TF_reenable: set_tsk_thread_flag(tsk, TIF_SINGLESTEP); regs->flags &= ~X86_EFLAGS_TF; + preempt_conditional_cli(regs); return; } diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index be73323ca95..a851eca6d04 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -380,7 +380,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) { struct task_struct *tsk = current; unsigned long condition; - siginfo_t info; + int si_code; get_debugreg(condition, 6); @@ -394,6 +394,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) SIGTRAP) == NOTIFY_STOP) return; + /* It's safe to allow irq's after DR6 has been saved */ preempt_conditional_sti(regs); /* Mask out spurious debug traps due to lazy DR7 setting */ @@ -402,6 +403,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) goto clear_dr7; } + /* Save debug status register where ptrace can see it */ tsk->thread.debugreg6 = condition; /* @@ -413,15 +415,14 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) goto clear_TF_reenable; } + si_code = get_si_code(condition); /* Ok, finally something we can handle */ - tsk->thread.trap_no = 1; - tsk->thread.error_code = error_code; - info.si_signo = SIGTRAP; - info.si_errno = 0; - info.si_code = get_si_code(condition); - info.si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL; - force_sig_info(SIGTRAP, &info, tsk); + send_sigtrap(tsk, regs, error_code, si_code); + /* + * Disable additional traps. They'll be re-enabled when + * the signal is delivered. + */ clear_dr7: set_debugreg(0, 7); preempt_conditional_cli(regs); |