1 files changed, 64 insertions, 14 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 7885722bdf4e..8bfa98757cd2 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -129,30 +129,58 @@ ENDPROC(ret_from_fork)
  * clobber the ip register.  This is OK because the ARM calling convention
  * allows it to be clobbered in subroutines and doesn't use it to hold
  * parameters.)
+ *
+ * When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
+ * for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
+ * arch/arm/kernel/ftrace.c).
  */
+
+#ifndef CONFIG_OLD_MCOUNT
+#if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4))
+#error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0.
+#endif
+#endif
+
 #ifdef CONFIG_DYNAMIC_FTRACE
-ENTRY(mcount)
+ENTRY(__gnu_mcount_nc)
+	mov	ip, lr
+	ldmia	sp!, {lr}
+	mov	pc, ip
+ENDPROC(__gnu_mcount_nc)
+
+ENTRY(ftrace_caller)
 	stmdb	sp!, {r0-r3, lr}
 	mov	r0, lr
 	sub	r0, r0, #MCOUNT_INSN_SIZE
+	ldr	r1, [sp, #20]
 
-	.globl mcount_call
-mcount_call:
+	.global	ftrace_call
+ftrace_call:
 	bl	ftrace_stub
-	ldr	lr, [fp, #-4]			@ restore lr
-	ldmia	sp!, {r0-r3, pc}
+	ldmia	sp!, {r0-r3, ip, lr}
+	mov	pc, ip
+ENDPROC(ftrace_caller)
 
-ENTRY(ftrace_caller)
+#ifdef CONFIG_OLD_MCOUNT
+ENTRY(mcount)
+	stmdb	sp!, {lr}
+	ldr	lr, [fp, #-4]
+	ldmia	sp!, {pc}
+ENDPROC(mcount)
+
+ENTRY(ftrace_caller_old)
 	stmdb	sp!, {r0-r3, lr}
 	ldr	r1, [fp, #-4]
 	mov	r0, lr
 	sub	r0, r0, #MCOUNT_INSN_SIZE
 
-	.globl ftrace_call
-ftrace_call:
+	.globl ftrace_call_old
+ftrace_call_old:
 	bl	ftrace_stub
 	ldr	lr, [fp, #-4]			@ restore lr
 	ldmia	sp!, {r0-r3, pc}
+ENDPROC(ftrace_caller_old)
+#endif
 
 #else
 
@@ -160,7 +188,7 @@ ENTRY(__gnu_mcount_nc)
 	stmdb	sp!, {r0-r3, lr}
 	ldr	r0, =ftrace_trace_function
 	ldr	r2, [r0]
-	adr	r0, ftrace_stub
+	adr	r0, .Lftrace_stub
 	cmp	r0, r2
 	bne	gnu_trace
 	ldmia	sp!, {r0-r3, ip, lr}
@@ -170,11 +198,19 @@ gnu_trace:
 	ldr	r1, [sp, #20]			@ lr of instrumented routine
 	mov	r0, lr
 	sub	r0, r0, #MCOUNT_INSN_SIZE
-	mov	lr, pc
+	adr	lr, BSYM(1f)
 	mov	pc, r2
+1:
 	ldmia	sp!, {r0-r3, ip, lr}
 	mov	pc, ip
+ENDPROC(__gnu_mcount_nc)
 
+#ifdef CONFIG_OLD_MCOUNT
+/*
+ * This is under an ifdef in order to force link-time errors for people trying
+ * to build with !FRAME_POINTER with a GCC which doesn't use the new-style
+ * mcount.
+ */
 ENTRY(mcount)
 	stmdb	sp!, {r0-r3, lr}
 	ldr	r0, =ftrace_trace_function
@@ -193,12 +229,15 @@ trace:
 	mov	pc, r2
 	ldr	lr, [fp, #-4]			@ restore lr
 	ldmia	sp!, {r0-r3, pc}
+ENDPROC(mcount)
+#endif
 
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
-	.globl ftrace_stub
-ftrace_stub:
+ENTRY(ftrace_stub)
+.Lftrace_stub:
 	mov	pc, lr
+ENDPROC(ftrace_stub)
 
 #endif /* CONFIG_FUNCTION_TRACER */
 
@@ -295,7 +334,6 @@ ENTRY(vector_swi)
 
 	get_thread_info tsk
 	adr	tbl, sys_call_table		@ load syscall table pointer
-	ldr	ip, [tsk, #TI_FLAGS]		@ check for syscall tracing
 
 #if defined(CONFIG_OABI_COMPAT)
 	/*
@@ -312,8 +350,20 @@ ENTRY(vector_swi)
 	eor	scno, scno, #__NR_SYSCALL_BASE	@ check OS number
 #endif
 
+	ldr	r10, [tsk, #TI_FLAGS]		@ check for syscall tracing
 	stmdb	sp!, {r4, r5}			@ push fifth and sixth args
-	tst	ip, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
+
+#ifdef CONFIG_SECCOMP
+	tst	r10, #_TIF_SECCOMP
+	beq	1f
+	mov	r0, scno
+	bl	__secure_computing	
+	add	r0, sp, #S_R0 + S_OFF		@ pointer to regs
+	ldmia	r0, {r0 - r3}			@ have to reload r0 - r3
+1:
+#endif
+
+	tst	r10, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
 	bne	__sys_trace
 
 	cmp	scno, #NR_syscalls		@ check upper syscall limit