From 21d44be7b6ff4c254dc971e2c99d4082dd470afd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 2 Sep 2020 15:26:00 +0200 Subject: [PATCH] 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) Signed-off-by: Thomas Gleixner Tested-by: Daniel Thompson Link: https://lore.kernel.org/r/20200902133201.292906672@infradead.org --- 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 ca9de59ffb87..7b7d9f23a9ad 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; }