[RFC PATCH 1/4] ARM: hw-breakpoint: add mechanism for hooking into prefetch aborts
Will Deacon
will.deacon at arm.com
Wed Mar 10 11:01:11 EST 2010
On ARM processors with hardware breakpoint and watchpoint support,
triggering these events results in a debug exception. These manifest
as prefetch and data aborts respectively.
arch/arm/mm/fault.c already provides hook_fault_code for hooking
into data aborts dependent on the DFSR. This patch adds a new function,
hook_ifault_code for hooking into prefetch aborts in the same manner.
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
arch/arm/include/asm/system.h | 3 +++
arch/arm/mm/fault.c | 11 +++++++++++
2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 058e7e9..7aa53e3 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -83,6 +83,9 @@ void arm_notify_die(const char *str, struct pt_regs *regs, struct siginfo *info,
void hook_fault_code(int nr, int (*fn)(unsigned long, unsigned int,
struct pt_regs *),
int sig, const char *name);
+void hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int,
+ struct pt_regs *),
+ int sig, const char *name);
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 9d40c34..9a04584 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -567,6 +567,17 @@ static struct fsr_info ifsr_info[] = {
{ do_bad, SIGBUS, 0, "unknown 31" },
};
+void __init
+hook_ifault_code(int nr, int (*fn)(unsigned long, unsigned int, struct pt_regs *),
+ int sig, const char *name)
+{
+ if (nr >= 0 && nr < ARRAY_SIZE(ifsr_info)) {
+ ifsr_info[nr].fn = fn;
+ ifsr_info[nr].sig = sig;
+ ifsr_info[nr].name = name;
+ }
+}
+
asmlinkage void __exception
do_PrefetchAbort(unsigned long addr, unsigned int ifsr, struct pt_regs *regs)
{
--
1.6.3.3
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