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| author | Mika Penttilä <mika.penttila@nextfour.com> | 2016-01-26 15:47:25 +0000 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-01-26 15:56:44 +0000 |
| commit | 57adec866c0440976c96a4b8f5b59fb411b1cacb (patch) | |
| tree | 704d55bf1775027161daf3c01cb373fc8e719a89 /arch | |
| parent | 531d3067314f63d80936c565dcd0fa01c7a1760f (diff) | |
| download | linux-57adec866c0440976c96a4b8f5b59fb411b1cacb.tar.gz | |
arm64: mm: avoid calling apply_to_page_range on empty range
Calling apply_to_page_range with an empty range results in a BUG_ON from the core code. This can be triggered by trying to load the st_drv module with CONFIG_DEBUG_SET_MODULE_RONX enabled: kernel BUG at mm/memory.c:1874! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000 PC is at apply_to_page_range+0x2cc/0x2d0 LR is at change_memory_common+0x80/0x108 This patch fixes the issue by making change_memory_common (called by the set_memory_* functions) a NOP when numpages == 0, therefore avoiding the erroneous call to apply_to_page_range and bringing us into line with x86 and s390. Cc: <stable@vger.kernel.org> Reviewed-by: Laura Abbott <labbott@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/mm/pageattr.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 3571c7309c5e..cf6240741134 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -57,6 +57,9 @@ static int change_memory_common(unsigned long addr, int numpages, if (end < MODULES_VADDR || end >= MODULES_END) return -EINVAL; + if (!numpages) + return 0; + data.set_mask = set_mask; data.clear_mask = clear_mask; |