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authorChristophe Leroy <christophe.leroy@c-s.fr>2019-01-31 10:08:58 +0000
committerMichael Ellerman <mpe@ellerman.id.au>2019-02-23 22:31:40 +1100
commited1cd6deb013a11959d17a94e35ce159197632da (patch)
treefcfdc0de67e7753db653d06938d939fa0f0e924f /arch/powerpc/Makefile
parent7aef376679a428c6b7792fb4ce93364fd02caad4 (diff)
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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/Makefile')
-rw-r--r--arch/powerpc/Makefile7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index ac033341ed55..53ffe935f3b0 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -427,6 +427,13 @@ else
endif
endif
+ifdef CONFIG_SMP
+prepare: task_cpu_prepare
+
+task_cpu_prepare: prepare0
+ $(eval KBUILD_CFLAGS += -D_TASK_CPU=$(shell awk '{if ($$2 == "TI_CPU") print $$3;}' include/generated/asm-offsets.h))
+endif
+
# Check toolchain versions:
# - gcc-4.6 is the minimum kernel-wide version so nothing required.
checkbin: