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authorChristophe Leroy <christophe.leroy@c-s.fr>2019-01-31 11:08:58 +0100
committerMichael Ellerman <mpe@ellerman.id.au>2019-02-23 12:31:40 +0100
commited1cd6deb013a11959d17a94e35ce159197632da (patch)
treefcfdc0de67e7753db653d06938d939fa0f0e924f /arch/powerpc/kernel/head_fsl_booke.S
parentpowerpc/idle/6xx: Use r1 with CURRENT_THREAD_INFO() (diff)
downloadlinux-ed1cd6deb013a11959d17a94e35ce159197632da.tar.xz
linux-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_fsl_booke.S')
-rw-r--r--arch/powerpc/kernel/head_fsl_booke.S7
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 6301bb24889a..11f38adbe020 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -719,8 +719,7 @@ finish_tlb_load:
/* Get the next_tlbcam_idx percpu var */
#ifdef CONFIG_SMP
- lwz r12, TASK_STACK-THREAD(r12)
- lwz r15, TI_CPU(r12)
+ lwz r15, TI_CPU-THREAD(r12)
lis r14, __per_cpu_offset@h
ori r14, r14, __per_cpu_offset@l
rlwinm r15, r15, 2, 0, 29
@@ -1093,8 +1092,8 @@ __secondary_start:
/* 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)
/* stack */
addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD