Re: [PATCH] perf/x86/intel: Fix minor memleak on Skylake perf initialization

[Thomas Gleixner]

On Wed, 27 Dec 2017, Andi Kleen wrote:

> From: Andi Kleen 

Fixed that yesterday already slightly different.

Re: [PATCH] perf/x86/intel: Fix minor memleak on Skylake perf initialization

[Thomas Gleixner]

On Wed, 27 Dec 2017, Andi Kleen wrote:

> From: Andi Kleen 

Fixed that yesterday already slightly different.

[PATCH] perf/x86/intel: Fix minor memleak on Skylake perf initialization

[Andi Kleen]

From: Andi Kleen 

Tommi reports:

I'm seeing this kmemleak report in v4.15-rc4:

unreferenced object 0x8801f3d5d720 (size 64):
  comm "swapper/0", pid 1, jiffies 4294667312 (age 2687.423s)
  hex dump (first 32 bytes):
60 d1 41 ad ff ff ff ff 20 d1 41 ad ff ff ff ff  `.A. .A.
80 d0 41 ad ff ff ff ff 40 d0 41 ad ff ff ff ff  ..A.@.A.
  backtrace:
[] intel_pmu_init+0x1844/0x1d38
[] init_hw_perf_events+0x8c/0x66f
[] do_one_initcall+0x7b/0x1d0
[<8ee1f02a>] kernel_init_freeable+0x163/0x2f9
[] kernel_init+0xf/0x120
[<38a99264>] ret_from_fork+0x24/0x30
[] 0x

$ ./scripts/faddr2line vmlinux intel_pmu_init+0x1844/0x1d38
intel_pmu_init+0x1844/0x1d38:
intel_pmu_init at arch/x86/events/intel/core.c:4296

Which matches line:
extra_attr = merge_attr(extra_attr, skl_format_attr);

So looks like "extra_attr" is leaked here.

Free the attribute in this case.

Reported-by: Tommi Rantala 
Cc: Tommi Rantala 
Fixes: a5df70c354c26 ( perf/x86: Only show format attributes)
Signed-off-by: Andi Kleen 
---
 arch/x86/events/intel/core.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 09c26a4f139c..71321f48e1e6 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3855,6 +3855,7 @@ __init int intel_pmu_init(void)
struct extra_reg *er;
int version, i;
struct attribute **extra_attr = NULL;
+   bool extra_attr_allocated = false;
char *name;
 
if (!cpu_has(_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
@@ -4294,6 +4295,7 @@ __init int intel_pmu_init(void)
extra_attr = boot_cpu_has(X86_FEATURE_RTM) ?
hsw_format_attr : nhm_format_attr;
extra_attr = merge_attr(extra_attr, skl_format_attr);
+   extra_attr_allocated = true;
x86_pmu.cpu_events = get_hsw_events_attrs();
intel_pmu_pebs_data_source_skl(
boot_cpu_data.x86_model == INTEL_FAM6_SKYLAKE_X);
@@ -4324,6 +4326,8 @@ __init int intel_pmu_init(void)
if (version >= 2 && extra_attr) {
x86_pmu.format_attrs = merge_attr(intel_arch3_formats_attr,
  extra_attr);
+   if (extra_attr_allocated)
+   kfree(extra_attr);
WARN_ON(!x86_pmu.format_attrs);
}
 
-- 
2.14.3

[PATCH] perf/x86/intel: Fix minor memleak on Skylake perf initialization

[Andi Kleen]

From: Andi Kleen 

Tommi reports:

I'm seeing this kmemleak report in v4.15-rc4:

unreferenced object 0x8801f3d5d720 (size 64):
  comm "swapper/0", pid 1, jiffies 4294667312 (age 2687.423s)
  hex dump (first 32 bytes):
60 d1 41 ad ff ff ff ff 20 d1 41 ad ff ff ff ff  `.A. .A.
80 d0 41 ad ff ff ff ff 40 d0 41 ad ff ff ff ff  ..A.@.A.
  backtrace:
[] intel_pmu_init+0x1844/0x1d38
[] init_hw_perf_events+0x8c/0x66f
[] do_one_initcall+0x7b/0x1d0
[<8ee1f02a>] kernel_init_freeable+0x163/0x2f9
[] kernel_init+0xf/0x120
[<38a99264>] ret_from_fork+0x24/0x30
[] 0x

$ ./scripts/faddr2line vmlinux intel_pmu_init+0x1844/0x1d38
intel_pmu_init+0x1844/0x1d38:
intel_pmu_init at arch/x86/events/intel/core.c:4296

Which matches line:
extra_attr = merge_attr(extra_attr, skl_format_attr);

So looks like "extra_attr" is leaked here.

Free the attribute in this case.

Reported-by: Tommi Rantala 
Cc: Tommi Rantala 
Fixes: a5df70c354c26 ( perf/x86: Only show format attributes)
Signed-off-by: Andi Kleen 
---
 arch/x86/events/intel/core.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 09c26a4f139c..71321f48e1e6 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3855,6 +3855,7 @@ __init int intel_pmu_init(void)
struct extra_reg *er;
int version, i;
struct attribute **extra_attr = NULL;
+   bool extra_attr_allocated = false;
char *name;
 
if (!cpu_has(_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
@@ -4294,6 +4295,7 @@ __init int intel_pmu_init(void)
extra_attr = boot_cpu_has(X86_FEATURE_RTM) ?
hsw_format_attr : nhm_format_attr;
extra_attr = merge_attr(extra_attr, skl_format_attr);
+   extra_attr_allocated = true;
x86_pmu.cpu_events = get_hsw_events_attrs();
intel_pmu_pebs_data_source_skl(
boot_cpu_data.x86_model == INTEL_FAM6_SKYLAKE_X);
@@ -4324,6 +4326,8 @@ __init int intel_pmu_init(void)
if (version >= 2 && extra_attr) {
x86_pmu.format_attrs = merge_attr(intel_arch3_formats_attr,
  extra_attr);
+   if (extra_attr_allocated)
+   kfree(extra_attr);
WARN_ON(!x86_pmu.format_attrs);
}
 
-- 
2.14.3