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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-01-31 10:08:58 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-02-23 22:31:40 +1100 |
| commit | ed1cd6deb013a11959d17a94e35ce159197632da (patch) | |
| tree | fcfdc0de67e7753db653d06938d939fa0f0e924f /arch/powerpc/kernel/entry_32.S | |
| parent | 7aef376679a428c6b7792fb4ce93364fd02caad4 (diff) | |
| download | linux-ed1cd6deb013a11959d17a94e35ce159197632da.tar.bz2 | |
powerpc: Activate CONFIG_THREAD_INFO_IN_TASK
This patch activates CONFIG_THREAD_INFO_IN_TASK which
moves the thread_info into task_struct.
Moving thread_info into task_struct has the following advantages:
- It protects thread_info from corruption in the case of stack
overflows.
- Its address is harder to determine if stack addresses are leaked,
making a number of attacks more difficult.
This has the following consequences:
- thread_info is now located at the beginning of task_struct.
- The 'cpu' field is now in task_struct, and only exists when
CONFIG_SMP is active.
- thread_info doesn't have anymore the 'task' field.
This patch:
- Removes all recopy of thread_info struct when the stack changes.
- Changes the CURRENT_THREAD_INFO() macro to point to current.
- Selects CONFIG_THREAD_INFO_IN_TASK.
- Modifies raw_smp_processor_id() to get ->cpu from current without
including linux/sched.h to avoid circular inclusion and without
including asm/asm-offsets.h to avoid symbol names duplication
between ASM constants and C constants.
- Modifies klp_init_thread_info() to take a task_struct pointer
argument.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add task_stack.h to livepatch.h to fix build fails]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_32.S | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index 063100df8325..f3618353c1c4 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -1165,10 +1165,6 @@ ret_from_debug_exc: mfspr r9,SPRN_SPRG_THREAD lwz r10,SAVED_KSP_LIMIT(r1) stw r10,KSP_LIMIT(r9) - lwz r9,TASK_STACK-THREAD(r9) - CURRENT_THREAD_INFO(r10, r1) - lwz r10,TI_PREEMPT(r10) - stw r10,TI_PREEMPT(r9) RESTORE_xSRR(SRR0,SRR1); RESTORE_xSRR(CSRR0,CSRR1); RESTORE_MMU_REGS; @@ -1291,10 +1287,13 @@ BEGIN_FTR_SECTION END_FTR_SECTION_IFSET(CPU_FTR_601) lwz r3,_TRAP(r1) andi. r0,r3,1 - beq 4f + beq 5f SAVE_NVGPRS(r1) rlwinm r3,r3,0,0,30 stw r3,_TRAP(r1) +5: mfspr r2,SPRN_SPRG_THREAD + addi r2,r2,-THREAD + tovirt(r2,r2) /* set back r2 to current */ 4: addi r3,r1,STACK_FRAME_OVERHEAD bl unrecoverable_exception /* shouldn't return */ |