leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[PATCH] x86_64: Don't schedule on exception stack on preemptive kernels

Browse Source 
Extends an earlier patch from John Blackwood to more exception handlers
that also run on the exception stacks.

Expand the use of preempt_conditional_{sti,cli} to all cases where
interrupts are to be re-enabled during exception handling while running
on an IST stack.

Based on original patch from Jan Beulich.

Cc: John Blackwood <john.blackwood@ccur.com>
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andi Kleen 2006-05-15 18:19:47 +02:00 committed by Linus Torvalds
parent fad7906d16
commit 40e59a6166
1 changed files with 17 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
arch/x86_64/kernel/traps.c
View File

@ -102,6 +102,8 @@ static inline void preempt_conditional_cli(struct pt_regs *regs)
{
if (regs->eflags & X86_EFLAGS_IF)
local_irq_disable();
/* Make sure to not schedule here because we could be running
on an exception stack. */
preempt_enable_no_resched();
}
@ -483,8 +485,6 @@ static void __kprobes do_trap(int trapnr, int signr, char *str,
{
struct task_struct *tsk = current;
conditional_sti(regs);
tsk->thread.error_code = error_code;
tsk->thread.trap_no = trapnr;
@ -521,6 +521,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
== NOTIFY_STOP) \
return; \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, NULL); \
}
@ -535,6 +536,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
== NOTIFY_STOP) \
return; \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, &info); \
}
@ -548,7 +550,17 @@ DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
DO_ERROR(18, SIGSEGV, "reserved", reserved)
DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
/* Runs on IST stack */
asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
{
if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
12, SIGBUS) == NOTIFY_STOP)
return;
preempt_conditional_sti(regs);
do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
preempt_conditional_cli(regs);
}
asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
{
@ -682,8 +694,9 @@ asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
return;
}
preempt_conditional_sti(regs);
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
return;
preempt_conditional_cli(regs);
}
/* Help handler running on IST stack to switch back to user stack