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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/head_44x.S | |
| parent | 7aef376679a428c6b7792fb4ce93364fd02caad4 (diff) | |
| download | lwn-ed1cd6deb013a11959d17a94e35ce159197632da.tar.gz lwn-ed1cd6deb013a11959d17a94e35ce159197632da.zip | |
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/head_44x.S')
| -rw-r--r-- | arch/powerpc/kernel/head_44x.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index 4e8c8bf50413..f94a93b6c2f2 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -1021,8 +1021,8 @@ _GLOBAL(start_secondary_47x) /* Get current's stack and current */ lis r1,secondary_ti@ha - lwz r1,secondary_ti@l(r1) - lwz r2,TI_TASK(r1) + lwz r2,secondary_ti@l(r1) + lwz r1,TASK_STACK(r2) /* Current stack pointer */ addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD |