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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-06-05 10:44:47 -0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-06-10 08:43:33 -0400 |
| commit | 354e7b761992a8e3923badaf705c4acbb9d5659d (patch) | |
| tree | ea12205a673d6f1c969c864da651e49db4ba87cf /arch/x86/xen | |
| parent | b85fffec7f5ba1c43171c63c046a97bac30a4561 (diff) | |
| download | linux-354e7b761992a8e3923badaf705c4acbb9d5659d.tar.bz2 | |
xen/spinlock: Don't leak interrupt name when offlining.
When the user does:
echo 0 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu1/online
kmemleak reports:
kmemleak: 7 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
unreferenced object 0xffff88003fa51260 (size 32):
comm "swapper/0", pid 1, jiffies 4294667339 (age 1027.789s)
hex dump (first 32 bytes):
73 70 69 6e 6c 6f 63 6b 31 00 00 00 00 00 00 00 spinlock1.......
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81660721>] kmemleak_alloc+0x21/0x50
[<ffffffff81190aac>] __kmalloc_track_caller+0xec/0x2a0
[<ffffffff812fe1bb>] kvasprintf+0x5b/0x90
[<ffffffff812fe228>] kasprintf+0x38/0x40
[<ffffffff81663789>] xen_init_lock_cpu+0x61/0xbe
[<ffffffff816633a6>] xen_cpu_up+0x66/0x3e8
[<ffffffff8166bbf5>] _cpu_up+0xd1/0x14b
[<ffffffff8166bd48>] cpu_up+0xd9/0xec
[<ffffffff81ae6e4a>] smp_init+0x4b/0xa3
[<ffffffff81ac4981>] kernel_init_freeable+0xdb/0x1e6
[<ffffffff8165ce39>] kernel_init+0x9/0xf0
[<ffffffff8167edfc>] ret_from_fork+0x7c/0xb0
[<ffffffffffffffff>] 0xffffffffffffffff
Instead of doing it like the "xen/smp: Don't leak interrupt name when offlining"
patch did (which has a per-cpu structure which contains both the
IRQ number and char*) we use a per-cpu pointers to a *char.
The reason is that the "__this_cpu_read(lock_kicker_irq);" macro
blows up with "__bad_size_call_parameter()" as the size of the
returned structure is not within the parameters of what it expects
and optimizes for.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/x86/xen')
| -rw-r--r-- | arch/x86/xen/spinlock.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 3002ec1bb71a..a40f8508e760 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -7,6 +7,7 @@ #include <linux/debugfs.h> #include <linux/log2.h> #include <linux/gfp.h> +#include <linux/slab.h> #include <asm/paravirt.h> @@ -165,6 +166,7 @@ static int xen_spin_trylock(struct arch_spinlock *lock) return old == 0; } +static DEFINE_PER_CPU(char *, irq_name); static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners); @@ -362,7 +364,7 @@ static irqreturn_t dummy_handler(int irq, void *dev_id) void __cpuinit xen_init_lock_cpu(int cpu) { int irq; - const char *name; + char *name; WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n", cpu, per_cpu(lock_kicker_irq, cpu)); @@ -385,6 +387,7 @@ void __cpuinit xen_init_lock_cpu(int cpu) if (irq >= 0) { disable_irq(irq); /* make sure it's never delivered */ per_cpu(lock_kicker_irq, cpu) = irq; + per_cpu(irq_name, cpu) = name; } printk("cpu %d spinlock event irq %d\n", cpu, irq); @@ -401,6 +404,8 @@ void xen_uninit_lock_cpu(int cpu) unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL); per_cpu(lock_kicker_irq, cpu) = -1; + kfree(per_cpu(irq_name, cpu)); + per_cpu(irq_name, cpu) = NULL; } void __init xen_init_spinlocks(void) |