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-rw-r--r--arch/arm/kernel/entry-common.S42
1 files changed, 29 insertions, 13 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 85a72b0809ca..94104bf69719 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -366,6 +366,16 @@ ENTRY(vector_swi)
#endif
zero_fp
+#ifdef CONFIG_ALIGNMENT_TRAP
+ ldr ip, __cr_alignment
+ ldr ip, [ip]
+ mcr p15, 0, ip, c1, c0 @ update control register
+#endif
+
+ enable_irq
+ ct_user_exit
+ get_thread_info tsk
+
/*
* Get the system call number.
*/
@@ -379,9 +389,9 @@ ENTRY(vector_swi)
#ifdef CONFIG_ARM_THUMB
tst r8, #PSR_T_BIT
movne r10, #0 @ no thumb OABI emulation
- ldreq r10, [lr, #-4] @ get SWI instruction
+ USER( ldreq r10, [lr, #-4] ) @ get SWI instruction
#else
- ldr r10, [lr, #-4] @ get SWI instruction
+ USER( ldr r10, [lr, #-4] ) @ get SWI instruction
#endif
#ifdef CONFIG_CPU_ENDIAN_BE8
rev r10, r10 @ little endian instruction
@@ -396,22 +406,13 @@ ENTRY(vector_swi)
/* Legacy ABI only, possibly thumb mode. */
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]
+ USER( ldreq scno, [lr, #-4] )
#else
/* Legacy ABI only. */
- ldr scno, [lr, #-4] @ get SWI instruction
+ USER( ldr scno, [lr, #-4] ) @ get SWI instruction
#endif
-#ifdef CONFIG_ALIGNMENT_TRAP
- ldr ip, __cr_alignment
- ldr ip, [ip]
- mcr p15, 0, ip, c1, c0 @ update control register
-#endif
- enable_irq
- ct_user_exit
-
- get_thread_info tsk
adr tbl, sys_call_table @ load syscall table pointer
#if defined(CONFIG_OABI_COMPAT)
@@ -446,6 +447,21 @@ local_restart:
eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
bcs arm_syscall
b sys_ni_syscall @ not private func
+
+#if defined(CONFIG_OABI_COMPAT) || !defined(CONFIG_AEABI)
+ /*
+ * We failed to handle a fault trying to access the page
+ * containing the swi instruction, but we're not really in a
+ * position to return -EFAULT. Instead, return back to the
+ * instruction and re-enter the user fault handling path trying
+ * to page it in. This will likely result in sending SEGV to the
+ * current task.
+ */
+9001:
+ sub lr, lr, #4
+ str lr, [sp, #S_PC]
+ b ret_fast_syscall
+#endif
ENDPROC(vector_swi)
/*