diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2020-01-31 12:34:54 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-02-19 12:46:08 +0100 |
| commit | 9e27086292aa880921a0f2b8501e5189d5efcf03 (patch) | |
| tree | 79b9c6c21074e5da094dce9cf912ad3b7bd313b3 /arch/powerpc/kernel/head_booke.h | |
| parent | powerpc/32s: Don't flush all TLBs when flushing one page (diff) | |
| download | linux-9e27086292aa880921a0f2b8501e5189d5efcf03.tar.xz linux-9e27086292aa880921a0f2b8501e5189d5efcf03.zip | |
powerpc/32: Warn and return ENOSYS on syscalls from kernel
Since commit b86fb88855ea ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb4f ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls from
kernel are unexpected and can have catastrophic consequences
as it will destroy the kernel stack.
Test MSR_PR on syscall entry. In case syscall is from kernel,
emit a warning and return ENOSYS error.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
Diffstat (limited to 'arch/powerpc/kernel/head_booke.h')
| -rw-r--r-- | arch/powerpc/kernel/head_booke.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h index 37fc84ed90e3..bd2e5ed8dd50 100644 --- a/arch/powerpc/kernel/head_booke.h +++ b/arch/powerpc/kernel/head_booke.h @@ -104,16 +104,18 @@ FTR_SECTION_ELSE #ifdef CONFIG_KVM_BOOKE_HV ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) #endif + mfspr r9, SPRN_SRR1 BOOKE_CLEAR_BTB(r11) + andi. r11, r9, MSR_PR lwz r11, TASK_STACK - THREAD(r10) rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */ + beq- 99f ALLOC_STACK_FRAME(r11, THREAD_SIZE - INT_FRAME_SIZE) stw r12, _CCR(r11) /* save various registers */ mflr r12 stw r12,_LINK(r11) mfspr r12,SPRN_SRR0 stw r1, GPR1(r11) - mfspr r9,SPRN_SRR1 stw r1, 0(r11) mr r1, r11 stw r12,_NIP(r11) @@ -176,6 +178,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) mtspr SPRN_SRR0,r11 SYNC RFI /* jump to handler, enable MMU */ +99: b ret_from_kernel_syscall .endm /* To handle the additional exception priority levels on 40x and Book-E |