From: Will Deacon will.deacon@arm.com
mainline inclusion from v5.0-rc1 commit 8cb3451b1f240ec4d36a9bfcd39cb6d59769a5b3 category: feature bugzilla: 30102 CVE: NA
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The comment about SYS_MEMBARRIER_SYNC_CORE relying on ERET being context-synchronizing is confusing and misplaced with kpti. Given that this is already documented under Documentation/ (see arch-support.txt for membarrier), remove the comment altogether.
Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Wang ShaoBo bobo.shaobowang@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/arm64/kernel/entry.S | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 286f8d3bd10f..54092ae9968a 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -361,10 +361,6 @@ alternative_else_nop_endif ldp x28, x29, [sp, #16 * 14] ldr lr, [sp, #S_LR] add sp, sp, #S_FRAME_SIZE // restore sp - /* - * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on eret context synchronization - * when returning from IPI handler, and when returning to user-space. - */
.if \el == 0 alternative_insn eret, nop, ARM64_UNMAP_KERNEL_AT_EL0