* [PATCH] x86/mm/kmmio: Use this_cpu_ptr() instead get_cpu_var() for kmmio_ctx
@ 2020-02-05 14:34 Sebastian Andrzej Siewior
2020-03-12 15:53 ` [tip: x86/mm] " tip-bot2 for Sebastian Andrzej Siewior
0 siblings, 1 reply; 2+ messages in thread
From: Sebastian Andrzej Siewior @ 2020-02-05 14:34 UTC (permalink / raw)
To: linux-kernel, nouveau
Cc: Steven Rostedt, Ingo Molnar, Karol Herbst, Pekka Paalanen,
Dave Hansen, Andy Lutomirski, Peter Zijlstra, Thomas Gleixner,
Borislav Petkov, H. Peter Anvin, x86, Sebastian Andrzej Siewior
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@linutronix.de>
---
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 49d7814b59a9b..9994353fb75de 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 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
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;
}
--
2.25.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [tip: x86/mm] x86/mm/kmmio: Use this_cpu_ptr() instead get_cpu_var() for kmmio_ctx
2020-02-05 14:34 [PATCH] x86/mm/kmmio: Use this_cpu_ptr() instead get_cpu_var() for kmmio_ctx Sebastian Andrzej Siewior
@ 2020-03-12 15:53 ` tip-bot2 for Sebastian Andrzej Siewior
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot2 for Sebastian Andrzej Siewior @ 2020-03-12 15:53 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Sebastian Andrzej Siewior, Borislav Petkov, x86, LKML
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@linutronix.de>
AuthorDate: Wed, 05 Feb 2020 15:34:26 +01:00
Committer: Borislav Petkov <bp@suse.de>
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@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200205143426.2592512-1-bigeasy@linutronix.de
---
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;
}
^ permalink raw reply related [flat|nested] 2+ messages in thread
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2020-02-05 14:34 [PATCH] x86/mm/kmmio: Use this_cpu_ptr() instead get_cpu_var() for kmmio_ctx Sebastian Andrzej Siewior
2020-03-12 15:53 ` [tip: x86/mm] " tip-bot2 for Sebastian Andrzej Siewior
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