* [PATCH] Remove a tiny memory leak in drivers/of
@ 2016-06-15 15:01 ` Mathieu Malaterre
0 siblings, 0 replies; 4+ messages in thread
From: Mathieu Malaterre @ 2016-06-15 15:01 UTC (permalink / raw)
To: linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ
Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A,
frowand.list-Re5JQEeQqe8AvxtiuMwx3w,
devicetree-u79uwXL29TY76Z2rM5mHXA, Mathieu Malaterre
On my PowerMac device-tree would generate a duplicate name:
[ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"
in this case a newly allocated name is generated by `safe_name`. However
in this case it is never deallocated.
The bug was found using kmemleak reported as:
unreferenced object 0xdf532e60 (size 32):
comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
hex dump (first 32 bytes):
6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1......
ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................
backtrace:
[<c02d3350>] kvasprintf+0x64/0xc8
[<c02d3400>] kasprintf+0x4c/0x5c
[<c0453814>] safe_name.isra.1+0x80/0xc4
[<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
[<c075f21c>] of_core_init+0x8c/0xf8
[<c0729594>] kernel_init_freeable+0xd4/0x208
[<c00047e8>] kernel_init+0x24/0x11c
[<c00158ec>] ret_from_kernel_thread+0x5c/0x64
Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331
Signed-off-by: Mathieu Malaterre <mathieu.malaterre-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
drivers/of/base.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ebf84e3..3cb11df 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -174,11 +174,15 @@ int __of_attach_node_sysfs(struct device_node *np)
rc = kobject_add(&np->kobj, NULL, "%s",
safe_name(&of_kset->kobj, "base"));
} else {
- name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+ const char *orig_name = kbasename(np->full_name);
+
+ name = safe_name(&np->parent->kobj, orig_name);
if (!name || !name[0])
return -EINVAL;
rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+ if (name != orig_name)
+ kfree(name);
}
if (rc)
return rc;
--
2.1.4
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] Remove a tiny memory leak in drivers/of
@ 2016-06-15 15:01 ` Mathieu Malaterre
0 siblings, 0 replies; 4+ messages in thread
From: Mathieu Malaterre @ 2016-06-15 15:01 UTC (permalink / raw)
To: linuxppc-dev; +Cc: robh+dt, frowand.list, devicetree, Mathieu Malaterre
On my PowerMac device-tree would generate a duplicate name:
[ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"
in this case a newly allocated name is generated by `safe_name`. However
in this case it is never deallocated.
The bug was found using kmemleak reported as:
unreferenced object 0xdf532e60 (size 32):
comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
hex dump (first 32 bytes):
6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1......
ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................
backtrace:
[<c02d3350>] kvasprintf+0x64/0xc8
[<c02d3400>] kasprintf+0x4c/0x5c
[<c0453814>] safe_name.isra.1+0x80/0xc4
[<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
[<c075f21c>] of_core_init+0x8c/0xf8
[<c0729594>] kernel_init_freeable+0xd4/0x208
[<c00047e8>] kernel_init+0x24/0x11c
[<c00158ec>] ret_from_kernel_thread+0x5c/0x64
Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331
Signed-off-by: Mathieu Malaterre <mathieu.malaterre@gmail.com>
---
drivers/of/base.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ebf84e3..3cb11df 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -174,11 +174,15 @@ int __of_attach_node_sysfs(struct device_node *np)
rc = kobject_add(&np->kobj, NULL, "%s",
safe_name(&of_kset->kobj, "base"));
} else {
- name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+ const char *orig_name = kbasename(np->full_name);
+
+ name = safe_name(&np->parent->kobj, orig_name);
if (!name || !name[0])
return -EINVAL;
rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
+ if (name != orig_name)
+ kfree(name);
}
if (rc)
return rc;
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] Remove a tiny memory leak in drivers/of
2016-06-15 15:01 ` Mathieu Malaterre
@ 2016-06-15 18:10 ` Frank Rowand
-1 siblings, 0 replies; 4+ messages in thread
From: Frank Rowand @ 2016-06-15 18:10 UTC (permalink / raw)
To: Mathieu Malaterre, linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ
Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A, devicetree-u79uwXL29TY76Z2rM5mHXA
Mathieu,
On 06/15/16 08:01, Mathieu Malaterre wrote:
> On my PowerMac device-tree would generate a duplicate name:
>
> [ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"
>
> in this case a newly allocated name is generated by `safe_name`. However
> in this case it is never deallocated.
>
> The bug was found using kmemleak reported as:
>
> unreferenced object 0xdf532e60 (size 32):
> comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
> hex dump (first 32 bytes):
> 6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1......
> ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................
> backtrace:
> [<c02d3350>] kvasprintf+0x64/0xc8
> [<c02d3400>] kasprintf+0x4c/0x5c
> [<c0453814>] safe_name.isra.1+0x80/0xc4
> [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
> [<c075f21c>] of_core_init+0x8c/0xf8
> [<c0729594>] kernel_init_freeable+0xd4/0x208
> [<c00047e8>] kernel_init+0x24/0x11c
> [<c00158ec>] ret_from_kernel_thread+0x5c/0x64
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331
> Signed-off-by: Mathieu Malaterre <mathieu.malaterre-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
> drivers/of/base.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index ebf84e3..3cb11df 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -174,11 +174,15 @@ int __of_attach_node_sysfs(struct device_node *np)
> rc = kobject_add(&np->kobj, NULL, "%s",
> safe_name(&of_kset->kobj, "base"));
> } else {
> - name = safe_name(&np->parent->kobj, kbasename(np->full_name));
> + const char *orig_name = kbasename(np->full_name);
> +
> + name = safe_name(&np->parent->kobj, orig_name);
> if (!name || !name[0])
> return -EINVAL;
>
> rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
> + if (name != orig_name)
> + kfree(name);
> }
> if (rc)
> return rc;
>
Thanks for reporting the issue and the cause of the issue.
You have exposed an issue that affects additional safe_name() call
sites that the proposed patch does not fix.
I will send you another patch that also addresses the other safe_name()
call sites, please test it to see if it fixes the memory leak that you
reported.
-Frank
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] Remove a tiny memory leak in drivers/of
@ 2016-06-15 18:10 ` Frank Rowand
0 siblings, 0 replies; 4+ messages in thread
From: Frank Rowand @ 2016-06-15 18:10 UTC (permalink / raw)
To: Mathieu Malaterre, linuxppc-dev; +Cc: robh+dt, devicetree
Mathieu,
On 06/15/16 08:01, Mathieu Malaterre wrote:
> On my PowerMac device-tree would generate a duplicate name:
>
> [ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"
>
> in this case a newly allocated name is generated by `safe_name`. However
> in this case it is never deallocated.
>
> The bug was found using kmemleak reported as:
>
> unreferenced object 0xdf532e60 (size 32):
> comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
> hex dump (first 32 bytes):
> 6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1......
> ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................
> backtrace:
> [<c02d3350>] kvasprintf+0x64/0xc8
> [<c02d3400>] kasprintf+0x4c/0x5c
> [<c0453814>] safe_name.isra.1+0x80/0xc4
> [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
> [<c075f21c>] of_core_init+0x8c/0xf8
> [<c0729594>] kernel_init_freeable+0xd4/0x208
> [<c00047e8>] kernel_init+0x24/0x11c
> [<c00158ec>] ret_from_kernel_thread+0x5c/0x64
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331
> Signed-off-by: Mathieu Malaterre <mathieu.malaterre@gmail.com>
> ---
> drivers/of/base.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index ebf84e3..3cb11df 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -174,11 +174,15 @@ int __of_attach_node_sysfs(struct device_node *np)
> rc = kobject_add(&np->kobj, NULL, "%s",
> safe_name(&of_kset->kobj, "base"));
> } else {
> - name = safe_name(&np->parent->kobj, kbasename(np->full_name));
> + const char *orig_name = kbasename(np->full_name);
> +
> + name = safe_name(&np->parent->kobj, orig_name);
> if (!name || !name[0])
> return -EINVAL;
>
> rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
> + if (name != orig_name)
> + kfree(name);
> }
> if (rc)
> return rc;
>
Thanks for reporting the issue and the cause of the issue.
You have exposed an issue that affects additional safe_name() call
sites that the proposed patch does not fix.
I will send you another patch that also addresses the other safe_name()
call sites, please test it to see if it fixes the memory leak that you
reported.
-Frank
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-06-15 15:01 [PATCH] Remove a tiny memory leak in drivers/of Mathieu Malaterre
2016-06-15 15:01 ` Mathieu Malaterre
[not found] ` <1466002919-535-1-git-send-email-mathieu.malaterre-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-06-15 18:10 ` Frank Rowand
2016-06-15 18:10 ` Frank Rowand
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