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-rw-r--r--arch/arm/kernel/entry-common.S44
1 files changed, 31 insertions, 13 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index e33c32d56193..ca3614dc6938 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -27,6 +27,14 @@
#include "entry-header.S"
+saved_psr .req r8
+#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
+saved_pc .req r9
+#define TRACE(x...) x
+#else
+saved_pc .req lr
+#define TRACE(x...)
+#endif
.align 5
#if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING))
@@ -146,16 +154,17 @@ 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.
+ TRACE( mov saved_pc, lr )
+ 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
alignment_trap r10, ip, __cr_alignment
- enable_irq
- ct_user_exit
- get_thread_info tsk
+ asm_trace_hardirqs_on save=0
+ enable_irq_notrace
+ ct_user_exit save=0
/*
* Get the system call number.
@@ -168,11 +177,11 @@ 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
@@ -183,15 +192,17 @@ 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
@@ -210,6 +221,12 @@ ENTRY(vector_swi)
bic scno, scno, #0xff000000 @ mask off SWI op-code
eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
#endif
+ get_thread_info tsk
+ /*
+ * Reload the registers that may have been corrupted on entry to
+ * the syscall assembly (by tracing or context tracking.)
+ */
+ TRACE( ldmia sp, {r0 - r3} )
local_restart:
ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
@@ -239,8 +256,9 @@ local_restart:
* current task.
*/
9001:
- sub lr, lr, #4
+ sub lr, saved_pc, #4
str lr, [sp, #S_PC]
+ get_thread_info tsk
b ret_fast_syscall
#endif
ENDPROC(vector_swi)