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authorStuart Menefy <stuart.menefy@st.com>2008-07-02 17:51:23 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-07-28 18:10:33 +0900
commitf2fb4e4f647dabf1177d3ce164988e73482d76b1 (patch)
tree5288184d2d8535c826c8b3c33d79b2529c83542b /arch/sh/mm
parent068f59143d821553e7a55cdbd69142b05e245d47 (diff)
downloadop-kernel-dev-f2fb4e4f647dabf1177d3ce164988e73482d76b1.zip
op-kernel-dev-f2fb4e4f647dabf1177d3ce164988e73482d76b1.tar.gz
sh: Conditionally re-enable IRQs in fault path.
The current kernel behaviour is to reenable interrupts unconditionally when taking a page fault. This patch changes this to only enable them if interrupts were previously enabled. It also fixes a problem seen with this fix in place: the kernel previously flushed the vsyscall page when handling a signal, which is not only unncessary, but caused a possible sleep with interrupts disabled. Signed-off-by: Stuart Menefy <stuart.menefy@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm')
-rw-r--r--arch/sh/mm/fault_32.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c
index d1fa275..0c776fd 100644
--- a/arch/sh/mm/fault_32.c
+++ b/arch/sh/mm/fault_32.c
@@ -37,16 +37,12 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
int fault;
siginfo_t info;
- trace_hardirqs_on();
- local_irq_enable();
-
#ifdef CONFIG_SH_KGDB
if (kgdb_nofault && kgdb_bus_err_hook)
kgdb_bus_err_hook();
#endif
tsk = current;
- mm = tsk->mm;
si_code = SEGV_MAPERR;
if (unlikely(address >= TASK_SIZE)) {
@@ -88,6 +84,14 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
return;
}
+ /* Only enable interrupts if they were on before the fault */
+ if ((regs->sr & SR_IMASK) != SR_IMASK) {
+ trace_hardirqs_on();
+ local_irq_enable();
+ }
+
+ mm = tsk->mm;
+
/*
* If we're in an interrupt or have no user
* context, we must not take the fault..
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