The following commit has been merged into the x86/mm branch of tip: Commit-ID: 6a9feaa8774f3b8210dfe40626a75ca047e4ecae Gitweb: https://git.kernel.org/tip/6a9feaa8774f3b8210dfe40626a75ca047e4ecae Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> AuthorDate: Wed, 05 Feb 2020 15:34:26 +01:00 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Thu, 12 Mar 2020 16:41:40 +01:00 x86/mm/kmmio: Use this_cpu_ptr() instead get_cpu_var() for kmmio_ctx Both call sites that access kmmio_ctx, access kmmio_ctx with interrupts disabled. There is no need to use get_cpu_var() which additionally disables preemption. Use this_cpu_ptr() to access the kmmio_ctx variable of the current CPU. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Link: https://lkml.kernel.org/r/20200205143426.2592512-1-bigeasy@xxxxxxxxxxxxx --- arch/x86/mm/kmmio.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c index 49d7814..9994353 100644 --- a/arch/x86/mm/kmmio.c +++ b/arch/x86/mm/kmmio.c @@ -260,7 +260,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) goto no_kmmio; } - ctx = &get_cpu_var(kmmio_ctx); + ctx = this_cpu_ptr(&kmmio_ctx); if (ctx->active) { if (page_base == ctx->addr) { /* @@ -285,7 +285,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) pr_emerg("previous hit was at 0x%08lx.\n", ctx->addr); disarm_kmmio_fault_page(faultpage); } - goto no_kmmio_ctx; + goto no_kmmio; } ctx->active++; @@ -314,11 +314,8 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr) * the user should drop to single cpu before tracing. */ - put_cpu_var(kmmio_ctx); return 1; /* fault handled */ -no_kmmio_ctx: - put_cpu_var(kmmio_ctx); no_kmmio: rcu_read_unlock(); preempt_enable_no_resched(); @@ -333,7 +330,7 @@ no_kmmio: static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) { int ret = 0; - struct kmmio_context *ctx = &get_cpu_var(kmmio_ctx); + struct kmmio_context *ctx = this_cpu_ptr(&kmmio_ctx); if (!ctx->active) { /* @@ -371,7 +368,6 @@ static int post_kmmio_handler(unsigned long condition, struct pt_regs *regs) if (!(regs->flags & X86_EFLAGS_TF)) ret = 1; out: - put_cpu_var(kmmio_ctx); return ret; }
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