The following commit has been merged into the x86/entry branch of tip:
Commit-ID: 21d44be7b6ff4c254dc971e2c99d4082dd470afd
Gitweb: https://git.kernel.org/tip/21d44be7b6ff4c254dc971e2c99d4082dd470afd
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 02 Sep 2020 15:26:00 +02:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 04 Sep 2020 15:12:56 +02:00
x86/debug: Simplify hw_breakpoint_handler()
This is called with interrupts disabled, there's no point in using
get_cpu() and per_cpu().
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200902133201.292906672@xxxxxxxxxxxxx
---
arch/x86/kernel/hw_breakpoint.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index ca9de59..7b7d9f2 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -487,7 +487,7 @@ EXPORT_SYMBOL_GPL(hw_breakpoint_restore);
*/
static int hw_breakpoint_handler(struct die_args *args)
{
- int i, cpu, rc = NOTIFY_STOP;
+ int i, rc = NOTIFY_STOP;
struct perf_event *bp;
unsigned long dr6;
unsigned long *dr6_p;
@@ -505,12 +505,10 @@ static int hw_breakpoint_handler(struct die_args *args)
return NOTIFY_DONE;
/*
- * Assert that local interrupts are disabled
* Reset the DRn bits in the virtualized register value.
* The ptrace trigger routine will add in whatever is needed.
*/
current->thread.debugreg6 &= ~DR_TRAP_BITS;
- cpu = get_cpu();
/* Handle all the breakpoints that were triggered */
for (i = 0; i < HBP_NUM; ++i) {
@@ -525,7 +523,7 @@ static int hw_breakpoint_handler(struct die_args *args)
*/
rcu_read_lock();
- bp = per_cpu(bp_per_reg[i], cpu);
+ bp = this_cpu_read(bp_per_reg[i]);
/*
* Reset the 'i'th TRAP bit in dr6 to denote completion of
* exception handling
@@ -560,8 +558,6 @@ static int hw_breakpoint_handler(struct die_args *args)
(dr6 & (~DR_TRAP_BITS)))
rc = NOTIFY_DONE;
- put_cpu();
-
return rc;
}
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