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| author | Russell King <rmk+kernel@armlinux.org.uk> | 2017-03-24 16:15:45 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@armlinux.org.uk> | 2017-08-02 14:15:04 +0100 |
| commit | 309ee04257d473ce87f2c7e99f6d69e933d307e3 (patch) | |
| tree | d3dacd0ed5bd0e8a420750028990edc723c5ea27 /arch/arm/kernel/entry-common.S | |
| parent | fed3c15531a225d95ec9b0aba4ff01c38de7a1b9 (diff) | |
| download | linux-309ee04257d473ce87f2c7e99f6d69e933d307e3.tar.gz | |
ARM: use aliases for registers in entry-common
Use aliases for the saved (and preserved) PSR and PC values so that we can control which registers are used. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index eb5cd77bf1d8..9abe47a206d9 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -27,6 +27,8 @@ #include "entry-header.S" +saved_psr .req r8 +saved_pc .req lr .align 5 #if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING)) @@ -141,9 +143,9 @@ ENTRY(vector_swi) ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr THUMB( mov r8, sp ) THUMB( store_user_sp_lr r8, r10, S_SP ) @ calling sp, lr - mrs r8, spsr @ called from non-FIQ mode, so ok. - str lr, [sp, #S_PC] @ Save calling PC - str r8, [sp, #S_PSR] @ Save CPSR + mrs saved_psr, spsr @ called from non-FIQ mode, so ok. + str saved_pc, [sp, #S_PC] @ Save calling PC + str saved_psr, [sp, #S_PSR] @ Save CPSR str r0, [sp, #S_OLD_R0] @ Save OLD_R0 #endif zero_fp @@ -163,11 +165,11 @@ ENTRY(vector_swi) * value to determine if it is an EABI or an old ABI call. */ #ifdef CONFIG_ARM_THUMB - tst r8, #PSR_T_BIT + tst saved_psr, #PSR_T_BIT movne r10, #0 @ no thumb OABI emulation - USER( ldreq r10, [lr, #-4] ) @ get SWI instruction + USER( ldreq r10, [saved_pc, #-4] ) @ get SWI instruction #else - USER( ldr r10, [lr, #-4] ) @ get SWI instruction + USER( ldr r10, [saved_pc, #-4] ) @ get SWI instruction #endif ARM_BE8(rev r10, r10) @ little endian instruction @@ -178,15 +180,17 @@ ENTRY(vector_swi) */ #elif defined(CONFIG_ARM_THUMB) /* Legacy ABI only, possibly thumb mode. */ - tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs + tst saved_psr, #PSR_T_BIT @ this is SPSR from save_user_regs addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in - USER( ldreq scno, [lr, #-4] ) + USER( ldreq scno, [saved_pc, #-4] ) #else /* Legacy ABI only. */ - USER( ldr scno, [lr, #-4] ) @ get SWI instruction + USER( ldr scno, [saved_pc, #-4] ) @ get SWI instruction #endif + /* saved_psr and saved_pc are now dead */ + uaccess_disable tbl adr tbl, sys_call_table @ load syscall table pointer @@ -234,7 +238,7 @@ local_restart: * current task. */ 9001: - sub lr, lr, #4 + sub lr, saved_pc, #4 str lr, [sp, #S_PC] b ret_fast_syscall #endif |