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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2013-09-17 16:57:34 +0200
committerTejun Heo <tj@kernel.org>2013-09-23 10:51:45 -0400
commitf851c8d8583891a6e0a447b539db3c39a4f5d43d (patch)
tree8f23dc2eaa1dab0475edff66c06b425c17a0304d /mm/percpu.c
parent272b98c6455f00884f0350f775c5342358ebb73f (diff)
downloadlinux-f851c8d8583891a6e0a447b539db3c39a4f5d43d.tar.bz2
percpu: fix bootmem error handling in pcpu_page_first_chunk()
If memory allocation of in pcpu_embed_first_chunk() fails, the allocated memory is not released correctly. In the release loop also the non-allocated elements are released which leads to the following kernel BUG on systems with very little memory: [ 0.000000] kernel BUG at mm/bootmem.c:307! [ 0.000000] illegal operation: 0001 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.10.0 #22 [ 0.000000] task: 0000000000a20ae0 ti: 0000000000a08000 task.ti: 0000000000a08000 [ 0.000000] Krnl PSW : 0400000180000000 0000000000abda7a (__free+0x116/0x154) [ 0.000000] R:0 T:1 IO:0 EX:0 Key:0 M:0 W:0 P:0 AS:0 CC:0 PM:0 EA:3 ... [ 0.000000] [<0000000000abdce2>] mark_bootmem_node+0xde/0xf0 [ 0.000000] [<0000000000abdd9c>] mark_bootmem+0xa8/0x118 [ 0.000000] [<0000000000abcbba>] pcpu_embed_first_chunk+0xe7a/0xf0c [ 0.000000] [<0000000000abcc96>] setup_per_cpu_areas+0x4a/0x28c To fix the problem now only allocated elements are released. This then leads to the correct kernel panic: [ 0.000000] Kernel panic - not syncing: Failed to initialize percpu areas. ... [ 0.000000] Call Trace: [ 0.000000] ([<000000000011307e>] show_trace+0x132/0x150) [ 0.000000] [<0000000000113160>] show_stack+0xc4/0xd4 [ 0.000000] [<00000000007127dc>] dump_stack+0x74/0xd8 [ 0.000000] [<00000000007123fe>] panic+0xea/0x264 [ 0.000000] [<0000000000b14814>] setup_per_cpu_areas+0x5c/0x28c tj: Flipped if conditional so that it doesn't need "continue". Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'mm/percpu.c')
-rw-r--r--mm/percpu.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/percpu.c b/mm/percpu.c
index 8c8e08f3a692..0d10defe951e 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1706,8 +1706,9 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
out_free_areas:
for (group = 0; group < ai->nr_groups; group++)
- free_fn(areas[group],
- ai->groups[group].nr_units * ai->unit_size);
+ if (areas[group])
+ free_fn(areas[group],
+ ai->groups[group].nr_units * ai->unit_size);
out_free:
pcpu_free_alloc_info(ai);
if (areas)