diff options
Diffstat (limited to 'arch/arm/kernel/entry-common.S')
| -rw-r--r-- | arch/arm/kernel/entry-common.S | 37 |
1 files changed, 28 insertions, 9 deletions
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index f5e75de0203e..e02790f28879 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -127,6 +127,10 @@ 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 @@ -136,30 +140,45 @@ ENDPROC(ret_from_fork) #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) + +#ifdef CONFIG_OLD_MCOUNT +ENTRY(mcount) + stmdb sp!, {lr} + ldr lr, [fp, #-4] + ldmia sp!, {pc} ENDPROC(mcount) -ENTRY(ftrace_caller) +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) +ENDPROC(ftrace_caller_old) +#endif #else |
