Revert "FROMLIST: arm64: preserve x18 when CPU is suspended"

Shadow call stack is now merged upstream for 5.9, so revert the patches
cherry-picked into android-mainline in preparation for pulling the upstream
version instead.

This reverts commit ee3f10f584.

Signed-off-by: Will Deacon <willdeacon@google.com>
Change-Id: Ie68af0533b0d25d8aa925ef365c897941d0dd21b
This commit is contained in:
Will Deacon
2020-06-09 12:53:16 +01:00
parent 861c24bf6c
commit 8cc585eb32
2 changed files with 1 additions and 15 deletions

View File

@@ -2,7 +2,7 @@
#ifndef __ASM_SUSPEND_H
#define __ASM_SUSPEND_H
#define NR_CTX_REGS 13
#define NR_CTX_REGS 12
#define NR_CALLEE_SAVED_REGS 12
/*

View File

@@ -58,8 +58,6 @@
* cpu_do_suspend - save CPU registers context
*
* x0: virtual address of context pointer
*
* This must be kept in sync with struct cpu_suspend_ctx in <asm/suspend.h>.
*/
SYM_FUNC_START(cpu_do_suspend)
mrs x2, tpidr_el0
@@ -84,11 +82,6 @@ alternative_endif
stp x8, x9, [x0, #48]
stp x10, x11, [x0, #64]
stp x12, x13, [x0, #80]
/*
* Save x18 as it may be used as a platform register, e.g. by shadow
* call stack.
*/
str x18, [x0, #96]
ret
SYM_FUNC_END(cpu_do_suspend)
@@ -105,13 +98,6 @@ SYM_FUNC_START(cpu_do_resume)
ldp x9, x10, [x0, #48]
ldp x11, x12, [x0, #64]
ldp x13, x14, [x0, #80]
/*
* Restore x18, as it may be used as a platform register, and clear
* the buffer to minimize the risk of exposure when used for shadow
* call stack.
*/
ldr x18, [x0, #96]
str xzr, [x0, #96]
msr tpidr_el0, x2
msr tpidrro_el0, x3
msr contextidr_el1, x4