| Message ID | 20190515094523.8095-1-aneesh.kumar@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | powerpc/mm: Drop VM_BUG_ON in get_region_id | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (8150a153c013aa2dd1ffae43370b89ac1347a7fb) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 1 warnings, 0 checks, 11 lines checked |
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; }
We can 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") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- arch/powerpc/include/asm/book3s/64/hash.h | 2 -- 1 file changed, 2 deletions(-)