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Groups > linux.kernel > #1622523
| From | Thomas Gleixner <tglx@linutronix.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [patch 03/13] ia64/salinfo: Replace racy task affinity logic |
| Date | 2017-04-12 22:30 +0200 |
| Message-ID | <tvx3P-QV-23@gated-at.bofh.it> (permalink) |
| References | <tvx3P-QV-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Some of the file operations in /proc/sal require to run code on the
requested cpu. This is achieved by temporarily setting the affinity of the
calling user space thread to the requested CPU and reset it to the original
affinity afterwards.
That's racy vs. CPU hotplug and concurrent affinity settings for that
thread resulting in code executing on the wrong CPU and overwriting the
new affinity setting.
Replace it by using work_on_cpu_safe() which guarantees to run the code on
the requested CPU or to fail in case the CPU is offline.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
---
arch/ia64/kernel/salinfo.c | 31 ++++++++++++-------------------
1 file changed, 12 insertions(+), 19 deletions(-)
--- a/arch/ia64/kernel/salinfo.c
+++ b/arch/ia64/kernel/salinfo.c
@@ -179,14 +179,14 @@ struct salinfo_platform_oemdata_parms {
const u8 *efi_guid;
u8 **oemdata;
u64 *oemdata_size;
- int ret;
};
-static void
+static long
salinfo_platform_oemdata_cpu(void *context)
{
struct salinfo_platform_oemdata_parms *parms = context;
- parms->ret = salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
+
+ return salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
}
static void
@@ -380,16 +380,7 @@ salinfo_log_release(struct inode *inode,
return 0;
}
-static void
-call_on_cpu(int cpu, void (*fn)(void *), void *arg)
-{
- cpumask_t save_cpus_allowed = current->cpus_allowed;
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
- (*fn)(arg);
- set_cpus_allowed_ptr(current, &save_cpus_allowed);
-}
-
-static void
+static long
salinfo_log_read_cpu(void *context)
{
struct salinfo_data *data = context;
@@ -399,6 +390,7 @@ salinfo_log_read_cpu(void *context)
/* Clear corrected errors as they are read from SAL */
if (rh->severity == sal_log_severity_corrected)
ia64_sal_clear_state_info(data->type);
+ return 0;
}
static void
@@ -430,7 +422,7 @@ salinfo_log_new_read(int cpu, struct sal
spin_unlock_irqrestore(&data_saved_lock, flags);
if (!data->saved_num)
- call_on_cpu(cpu, salinfo_log_read_cpu, data);
+ work_on_cpu_safe(cpu, salinfo_log_read_cpu, data);
if (!data->log_size) {
data->state = STATE_NO_DATA;
cpumask_clear_cpu(cpu, &data->cpu_event);
@@ -459,11 +451,13 @@ salinfo_log_read(struct file *file, char
return simple_read_from_buffer(buffer, count, ppos, buf, bufsize);
}
-static void
+static long
salinfo_log_clear_cpu(void *context)
{
struct salinfo_data *data = context;
+
ia64_sal_clear_state_info(data->type);
+ return 0;
}
static int
@@ -486,7 +480,7 @@ salinfo_log_clear(struct salinfo_data *d
rh = (sal_log_record_header_t *)(data->log_buffer);
/* Corrected errors have already been cleared from SAL */
if (rh->severity != sal_log_severity_corrected)
- call_on_cpu(cpu, salinfo_log_clear_cpu, data);
+ work_on_cpu_safe(cpu, salinfo_log_clear_cpu, data);
/* clearing a record may make a new record visible */
salinfo_log_new_read(cpu, data);
if (data->state == STATE_LOG_RECORD) {
@@ -531,9 +525,8 @@ salinfo_log_write(struct file *file, con
.oemdata = &data->oemdata,
.oemdata_size = &data->oemdata_size
};
- call_on_cpu(cpu, salinfo_platform_oemdata_cpu, &parms);
- if (parms.ret)
- count = parms.ret;
+ count = work_on_cpu_safe(cpu, salinfo_platform_oemdata_cpu,
+ &parms);
} else
data->oemdata_size = 0;
} else
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[patch 00/13] sched/treewide: Clean up various racy task affinity issues Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
[patch 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-13 05:00 +0200
[patch V2 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-13 10:20 +0200
[patch V3 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-13 10:30 +0200
[tip:sched/core] cpufreq/sparc-us2e: Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
Re: [patch V2 12/13] cpufreq/sparc-us2e: Replace racy task affinity logic David Miller <davem@davemloft.net> - 2017-04-13 17:00 +0200
[patch 03/13] ia64/salinfo: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
[tip:sched/core] ia64/salinfo: Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 04/13] ia64/sn/hwperf: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
[patch V 2 04/13] ia64/sn/hwperf: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 23:00 +0200
[tip:sched/core] ia64/sn/hwperf: Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 11/13] cpufreq/sparc-us3: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 11/13] cpufreq/sparc-us3: Replace racy task affinity logic Viresh Kumar <viresh.kumar@linaro.org> - 2017-04-13 04:50 +0200
[tip:sched/core] cpufreq/sparc-us3: Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 01/13] ia64/topology: Remove cpus_allowed manipulation Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
[tip:sched/core] ia64/topology: Remove cpus_allowed manipulation tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 07/13] ACPI/processor: Fix error handling in __acpi_processor_start() Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
[tip:sched/core] ACPI/processor: Fix error handling in __acpi_processor_start() tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 08/13] ACPI/processor: Replace racy task affinity logic. Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 08/13] ACPI/processor: Replace racy task affinity logic. Peter Zijlstra <peterz@infradead.org> - 2017-04-13 13:50 +0200
Re: [patch 08/13] ACPI/processor: Replace racy task affinity logic. Thomas Gleixner <tglx@linutronix.de> - 2017-04-13 14:10 +0200
Re: [patch 08/13] ACPI/processor: Replace racy task affinity logic. Peter Zijlstra <peterz@infradead.org> - 2017-04-13 15:00 +0200
[tip:sched/core] ACPI/processor: Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 13/13] crypto: n2 - Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 13/13] crypto: n2 - Replace racy task affinity logic Herbert Xu <herbert@gondor.apana.org.au> - 2017-04-13 07:40 +0200
[patch V2 13/13] crypto: n2 - Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-13 10:30 +0200
Re: [patch V2 13/13] crypto: n2 - Replace racy task affinity logic David Miller <davem@davemloft.net> - 2017-04-13 17:00 +0200
[tip:sched/core] crypto: N2 - Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:40 +0200
[patch 05/13] powerpc/smp: Replace open coded task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 05/13] powerpc/smp: Replace open coded task affinity logic Michael Ellerman <mpe@ellerman.id.au> - 2017-04-13 07:50 +0200
[tip:sched/core] powerpc/smp: Replace open coded task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
[patch 06/13] sparc/sysfs: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 06/13] sparc/sysfs: Replace racy task affinity logic David Miller <davem@davemloft.net> - 2017-04-13 04:00 +0200
[patch V2 06/13] sparc/sysfs: Replace racy task affinity logic Thomas Gleixner <tglx@linutronix.de> - 2017-04-13 10:20 +0200
[tip:sched/core] sparc/sysfs: Replace racy task affinity logic tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:20 +0200
[patch 02/13] workqueue: Provide work_on_cpu_safe() Thomas Gleixner <tglx@linutronix.de> - 2017-04-12 22:30 +0200
Re: [patch 02/13] workqueue: Provide work_on_cpu_safe() Dou Liyang <douly.fnst@cn.fujitsu.com> - 2017-04-13 13:20 +0200
Re: [patch 02/13] workqueue: Provide work_on_cpu_safe() Thomas Gleixner <tglx@linutronix.de> - 2017-04-13 23:30 +0200
Re: [patch 02/13] workqueue: Provide work_on_cpu_safe() Tejun Heo <tj@kernel.org> - 2017-04-14 06:20 +0200
Re: [patch 02/13] workqueue: Provide work_on_cpu_safe() Peter Zijlstra <peterz@infradead.org> - 2017-04-14 11:00 +0200
Re: [patch 02/13] workqueue: Provide work_on_cpu_safe() Thomas Gleixner <tglx@linutronix.de> - 2017-04-14 12:00 +0200
Re: [patch 02/13] workqueue: Provide work_on_cpu_safe() Peter Zijlstra <peterz@infradead.org> - 2017-04-14 12:00 +0200
[tip:sched/core] workqueue: Provide work_on_cpu_safe() tip-bot for Thomas Gleixner <tipbot@zytor.com> - 2017-04-15 16:30 +0200
Re: [patch 00/13] sched/treewide: Clean up various racy task affinity issues Peter Zijlstra <peterz@infradead.org> - 2017-04-13 11:10 +0200
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