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| author |   Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2020-12-08 08:45:39 +0530 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2020-12-08 21:40:54 +1100 |
| commit | 475c8749d9542392d7e0855097d29ed14877ad0a (patch) | |
| tree | 2a9b9e131fb1f2d29d220d9f95de5742634765ad /arch/powerpc/include/asm/nohash | |
| parent | powerpc/powernv/idle: Restore CIABR after idle for Power9 (diff) | |
| download | linux-dev-475c8749d9542392d7e0855097d29ed14877ad0a.tar.xz linux-dev-475c8749d9542392d7e0855097d29ed14877ad0a.zip | |
powerpc/book3s64/kuap: Improve error reporting with KUAP
This partially reverts commit eb232b162446 ("powerpc/book3s64/kuap: Improve
error reporting with KUAP") and update the fault handler to print
[ 55.022514] Kernel attempted to access user page (7e6725b70000) - exploit attempt? (uid: 0)
[ 55.022528] BUG: Unable to handle kernel data access on read at 0x7e6725b70000
[ 55.022533] Faulting instruction address: 0xc000000000e8b9bc
[ 55.022540] Oops: Kernel access of bad area, sig: 11 [#1]
....
when the kernel access userspace address without unlocking AMR.
bad_kuap_fault() is added as part of commit 5e5be3aed230 ("powerpc/mm: Detect
bad KUAP faults") to catch userspace access incorrectly blocked by AMR. Hence
retain the full stack dump there even with hash translation. Also, add a comment
explaining the difference between hash and radix.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201208031539.84878-1-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm/nohash')
| -rw-r--r-- | arch/powerpc/include/asm/nohash/32/kup-8xx.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index 7bdd9e5b63ed..567cdc557402 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -60,8 +60,8 @@ static inline void restore_user_access(unsigned long flags) mtspr(SPRN_MD_AP, flags); } -static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address, - bool is_write, unsigned long error_code) +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xff000000), "Bug: fault blocked by AP register !"); |