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| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2019-05-15 15:15:23 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-05-17 00:40:01 +1000 |
| commit | 6457f42eb3f6e9552366631bd5aeb096ae5f599a (patch) | |
| tree | 8f793ea65a12ad6d5ddcdd1c6d2498d9a0aaf072 /arch/powerpc/include/asm | |
| parent | 7338874c337f01dc84597a5500a588732725ffc6 (diff) | |
| download | lwn-6457f42eb3f6e9552366631bd5aeb096ae5f599a.tar.gz lwn-6457f42eb3f6e9552366631bd5aeb096ae5f599a.zip | |
powerpc/mm: Drop VM_BUG_ON in get_region_id()
We call get_region_id() without validating the ea value. That means
with a wrong ea value we hit the BUG as below.
kernel BUG at arch/powerpc/include/asm/book3s/64/hash.h:129!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
CPU: 0 PID: 3937 Comm: access_tests Not tainted 5.1.0
....
NIP [c00000000007ba20] do_slb_fault+0x70/0x320
LR [c00000000000896c] data_access_slb_common+0x15c/0x1a0
Fix this by removing the VM_BUG_ON. All callers make sure the returned
region id is valid and error out otherwise.
Fixes: 0034d395f89d ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range")
Reported-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/hash.h | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index 1d1183048cfd..5486087e64ea 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -122,11 +122,9 @@ static inline int get_region_id(unsigned long ea) if (ea < H_KERN_VIRT_START) return LINEAR_MAP_REGION_ID; - VM_BUG_ON(id != 0xc); BUILD_BUG_ON(NON_LINEAR_REGION_ID(H_VMALLOC_START) != 2); region_id = NON_LINEAR_REGION_ID(ea); - VM_BUG_ON(region_id > VMEMMAP_REGION_ID); return region_id; } |