1 files changed, 44 insertions, 21 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 53a7e0dea44d..3f8d0e3aefab 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -9,19 +9,10 @@
  */
 #include <linux/config.h>
 
-#include <asm/thread_info.h>
-#include <asm/ptrace.h>
 #include <asm/unistd.h>
 
 #include "entry-header.S"
 
-/* 
- * We rely on the fact that R0 is at the bottom of the stack (due to
- * slow/fast restore user regs).
- */
-#if S_R0 != 0
-#error "Please fix"
-#endif
 
         .align  5
 /*
@@ -30,11 +21,19 @@
  * stack.
  */
 ret_fast_syscall:
-        disable_irq r1                          @ disable interrupts
+        disable_irq                             @ disable interrupts
         ldr     r1, [tsk, #TI_FLAGS]
         tst     r1, #_TIF_WORK_MASK
         bne     fast_work_pending
-        fast_restore_user_regs
+
+        @ fast_restore_user_regs
+        ldr     r1, [sp, #S_OFF + S_PSR]        @ get calling cpsr
+        ldr     lr, [sp, #S_OFF + S_PC]!        @ get pc
+        msr     spsr_cxsf, r1                   @ save in spsr_svc
+        ldmdb   sp, {r1 - lr}^                  @ get calling r1 - lr
+        mov     r0, r0
+        add     sp, sp, #S_FRAME_SIZE - S_PC
+        movs    pc, lr                          @ return & move spsr_svc into cpsr
 
 /*
  * Ok, we need to do extra processing, enter the slow path.
@@ -49,7 +48,7 @@ work_pending:
         mov     r0, sp                          @ 'regs'
         mov     r2, why                         @ 'syscall'
         bl      do_notify_resume
-        disable_irq r1                          @ disable interrupts
+        disable_irq                             @ disable interrupts
         b       no_work_pending
 
 work_resched:
@@ -59,12 +58,19 @@ work_resched:
  */
 ENTRY(ret_to_user)
 ret_slow_syscall:
-        disable_irq r1                          @ disable interrupts
+        disable_irq                             @ disable interrupts
         ldr     r1, [tsk, #TI_FLAGS]
         tst     r1, #_TIF_WORK_MASK
         bne     work_pending
 no_work_pending:
-        slow_restore_user_regs
+        @ slow_restore_user_regs
+        ldr     r1, [sp, #S_PSR]                @ get calling cpsr
+        ldr     lr, [sp, #S_PC]!                @ get pc
+        msr     spsr_cxsf, r1                   @ save in spsr_svc
+        ldmdb   sp, {r0 - lr}^                  @ get calling r1 - lr
+        mov     r0, r0
+        add     sp, sp, #S_FRAME_SIZE - S_PC
+        movs    pc, lr                          @ return & move spsr_svc into cpsr
 
 /*
  * This is how we return from a fork.
@@ -116,9 +122,26 @@ ENTRY(ret_from_fork)
 
         .align  5
 ENTRY(vector_swi)
-        save_user_regs
+        sub     sp, sp, #S_FRAME_SIZE
+        stmia   sp, {r0 - r12}                  @ Calling r0 - r12
+        add     r8, sp, #S_PC
+        stmdb   r8, {sp, lr}^                   @ 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
+        str     r0, [sp, #S_OLD_R0]             @ Save OLD_R0
         zero_fp
-        get_scno
+
+        /*
+         * Get the system call number.
+         */
+#ifdef CONFIG_ARM_THUMB
+        tst     r8, #PSR_T_BIT                  @ this is SPSR from save_user_regs
+        addne   scno, r7, #__NR_SYSCALL_BASE    @ put OS number in
+        ldreq   scno, [lr, #-4]
+#else
+        ldr     scno, [lr, #-4]                 @ get SWI instruction
+#endif
         arm710_bug_check scno, ip
 
 #ifdef CONFIG_ALIGNMENT_TRAP
@@ -126,14 +149,14 @@ ENTRY(vector_swi)
         ldr     ip, [ip]
         mcr     p15, 0, ip, c1, c0              @ update control register
 #endif
-        enable_irq ip
+        enable_irq
 
         str     r4, [sp, #-S_OFF]!              @ push fifth arg
 
         get_thread_info tsk
         ldr     ip, [tsk, #TI_FLAGS]            @ check for syscall tracing
         bic     scno, scno, #0xff000000         @ mask off SWI op-code
-        eor     scno, scno, #OS_NUMBER << 20    @ check OS number
+        eor     scno, scno, #__NR_SYSCALL_BASE  @ check OS number
         adr     tbl, sys_call_table             @ load syscall table pointer
         tst     ip, #_TIF_SYSCALL_TRACE         @ are we tracing syscalls?
         bne     __sys_trace
@@ -144,8 +167,8 @@ ENTRY(vector_swi)
 
         add     r1, sp, #S_OFF
 2:      mov     why, #0                         @ no longer a real syscall
-        cmp     scno, #ARMSWI_OFFSET
-        eor     r0, scno, #OS_NUMBER << 20      @ put OS number back
+        cmp     scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
+        eor     r0, scno, #__NR_SYSCALL_BASE    @ put OS number back
         bcs     arm_syscall     
         b       sys_ni_syscall                  @ not private func
 
@@ -190,7 +213,7 @@ ENTRY(sys_call_table)
 @ r5 = syscall table
                 .type   sys_syscall, #function
 sys_syscall:
-                eor     scno, r0, #OS_NUMBER << 20
+                eor     scno, r0, #__NR_SYSCALL_BASE
                 cmp     scno, #__NR_syscall - __NR_SYSCALL_BASE
                 cmpne   scno, #NR_syscalls      @ check range
                 stmloia sp, {r5, r6}            @ shuffle args