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-rw-r--r--arch/arm/kernel/entry-common.S78
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
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