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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/asm-offsets.c | |
| parent | powerpc/idle/6xx: Use r1 with CURRENT_THREAD_INFO() (diff) | |
| download | linux-dev-ed1cd6deb013a11959d17a94e35ce159197632da.tar.xz linux-dev-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/asm-offsets.c')
| -rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index ca55027f47a4..ca3fb836cbb9 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -13,6 +13,8 @@ * 2 of the License, or (at your option) any later version. */ +#define GENERATING_ASM_OFFSETS /* asm/smp.h */ + #include <linux/compat.h> #include <linux/signal.h> #include <linux/sched.h> @@ -97,6 +99,9 @@ int main(void) #endif #endif /* CONFIG_PPC64 */ OFFSET(TASK_STACK, task_struct, stack); +#ifdef CONFIG_SMP + OFFSET(TI_CPU, task_struct, cpu); +#endif #ifdef CONFIG_LIVEPATCH OFFSET(TI_livepatch_sp, thread_info, livepatch_sp); @@ -164,8 +169,6 @@ int main(void) OFFSET(TI_FLAGS, thread_info, flags); OFFSET(TI_LOCAL_FLAGS, thread_info, local_flags); OFFSET(TI_PREEMPT, thread_info, preempt_count); - OFFSET(TI_TASK, thread_info, task); - OFFSET(TI_CPU, thread_info, cpu); #ifdef CONFIG_PPC64 OFFSET(DCACHEL1BLOCKSIZE, ppc64_caches, l1d.block_size); |