On 05/15/2013 10:02 AM, Catalin Marinas wrote:
On Wed, May 15, 2013 at 04:15:46AM +0100, Larry Finger wrote:
I do not see that particular one; however, I see 4 instances of
unreferenced object 0xffff8800b7979750 (size 8):
comm "swapper/0", pid 1, jiffies 4294892402 (age 21888.316s)
hex dump (first 8 bytes):
31 38 00 b7 00 88 ff ff 18......
backtrace:
[<ffffffff81432ea1>] kmemleak_alloc+0x21/0x50
[<ffffffff81145d50>] __kmalloc_track_caller+0x140/0x2b0
[<ffffffff81119fb5>] kstrdup+0x35/0x70
[<ffffffff8125febc>] acpi_set_pnp_ids+0xd0/0x304
[<ffffffff81260c47>] acpi_scan_init_hotplug+0x47/0xa1
[<ffffffff81261223>] acpi_bus_check_add+0x66/0xd7
[<ffffffff8127877a>] acpi_ns_walk_namespace+0xb9/0x173
[<ffffffff81278bf3>] acpi_walk_namespace+0x93/0xc6
[<ffffffff812612dc>] acpi_bus_scan+0x48/0x9a
[<ffffffff818c983d>] acpi_scan_init+0x57/0x14b
[<ffffffff818c966a>] acpi_init+0x244/0x286
[<ffffffff810002fa>] do_one_initcall+0x10a/0x160
[<ffffffff8189cef0>] kernel_init_freeable+0x103/0x192
[<ffffffff814313a9>] kernel_init+0x9/0xf0
[<ffffffff8144992c>] ret_from_fork+0x7c/0xb0
[<ffffffffffffffff>] 0xffffffffffffffff
All four were allocated early in the bootup, and are the only leaks reported in
my system. I have not yet tested to see if they are false.
This looks to me like a real leak, possibly introduced by commit
6b772e8f9 (ACPI: Update PNPID match handling for notify). The
acpi_scan_init_hotplug() function calls acpi_set_pnp_ids() which
allocates pnp.unique_id (kstrdup()) but for some reason it fails and
does not set pnp.type.hardware_id. The return does not call
acpi_free_pnp_ids() which would be responsible for such freeing.
Something like below, but not tested and may fail some NULL pointer
checks:
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index fe158fd..c1bc608 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1785,7 +1785,7 @@ static void acpi_scan_init_hotplug(acpi_handle handle,
int type)
acpi_set_pnp_ids(handle, &pnp, type);
if (!pnp.type.hardware_id)
- return;
+ goto out;
/*
* This relies on the fact that acpi_install_notify_handler() will not
@@ -1800,6 +1800,7 @@ static void acpi_scan_init_hotplug(acpi_handle handle,
int type)
}
}
+out:
acpi_free_pnp_ids(&pnp);
}
This patch fixes the memory leaks on my system. My kmemleak scans are now clean
again. You may add a "Tested-by: Larry Finger <larry.fin...@lwfinger.net>".
Thanks,
Larry
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