The patch titled
x86_64: Don't schedule on exception stack on preemptive kernels
has been removed from the -mm tree. Its filename is
x86_64-dont-schedule-on-exception.patch
This patch was probably dropped from -mm because
it has now been merged into a subsystem tree or
into Linus's tree, or because it was folded into
its parent patch in the -mm tree.
From: "Andi Kleen" <ak@xxxxxxx>
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@xxxxxxxx>
Cc: <jbeulich@xxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/x86_64/kernel/traps.c | 21 +++++++++++++++++----
1 files changed, 17 insertions(+), 4 deletions(-)
diff -puN arch/x86_64/kernel/traps.c~x86_64-dont-schedule-on-exception arch/x86_64/kernel/traps.c
--- devel/arch/x86_64/kernel/traps.c~x86_64-dont-schedule-on-exception 2006-05-15 21:43:23.000000000 -0700
+++ devel-akpm/arch/x86_64/kernel/traps.c 2006-05-15 21:43:23.000000000 -0700
@@ -102,6 +102,8 @@ static inline void preempt_conditional_c
{
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
{
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
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
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", inv
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
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
_
Patches currently in -mm which might be from ak@xxxxxxx are
origin.patch
x86_64-dont-warn-for-overflow-in-nommu-case-when-dma_mask-is-32bit-fix.patch
git-acpi.patch
git-agpgart.patch
x86_64-mm-remove-un-set_nmi_callback-and-reserve-release_lapic_nmi-functions-x86-fix.patch
x86_64-mm-remove-un-set_nmi_callback-and-reserve-release_lapic_nmi-functions-x86-fix-fix.patch
x86_64-mm-remove-un-set_nmi_callback-and-reserve-release_lapic_nmi-functions-x86-fix-fix-fix.patch
x86_64-mm-remove-un-set_nmi_callback-and-reserve-release_lapic_nmi-functions-x86_64-fix.patch
x86_64-mm-remove-un-set_nmi_callback-and-reserve-release_lapic_nmi-functions-x86_64-fix-fix.patch
x86_64-mm-serialize-assign_irq_vector-use-of-static-variables-fix.patch
-
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