diff options
Diffstat (limited to 'arch/arm/kernel/entry-ftrace.S')
| -rw-r--r-- | arch/arm/kernel/entry-ftrace.S | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S index c73c4030ca5d..efcd9f25a14b 100644 --- a/arch/arm/kernel/entry-ftrace.S +++ b/arch/arm/kernel/entry-ftrace.S @@ -92,12 +92,95 @@ 2: mcount_exit .endm +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS + +.macro __ftrace_regs_caller + + sub sp, sp, #8 @ space for PC and CPSR OLD_R0, + @ OLD_R0 will overwrite previous LR + + add ip, sp, #12 @ move in IP the value of SP as it was + @ before the push {lr} of the mcount mechanism + + str lr, [sp, #0] @ store LR instead of PC + + ldr lr, [sp, #8] @ get previous LR + + str r0, [sp, #8] @ write r0 as OLD_R0 over previous LR + + stmdb sp!, {ip, lr} + stmdb sp!, {r0-r11, lr} + + @ stack content at this point: + @ 0 4 48 52 56 60 64 68 72 + @ R0 | R1 | ... | LR | SP + 4 | previous LR | LR | PSR | OLD_R0 | + + mov r3, sp @ struct pt_regs* + + ldr r2, =function_trace_op + ldr r2, [r2] @ pointer to the current + @ function tracing op + + ldr r1, [sp, #S_LR] @ lr of instrumented func + + ldr lr, [sp, #S_PC] @ get LR + + mcount_adjust_addr r0, lr @ instrumented function + + .globl ftrace_regs_call +ftrace_regs_call: + bl ftrace_stub + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + .globl ftrace_graph_regs_call +ftrace_graph_regs_call: + mov r0, r0 +#endif + + @ pop saved regs + ldmia sp!, {r0-r12} @ restore r0 through r12 + ldr ip, [sp, #8] @ restore PC + ldr lr, [sp, #4] @ restore LR + ldr sp, [sp, #0] @ restore SP + mov pc, ip @ return +.endm + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +.macro __ftrace_graph_regs_caller + + sub r0, fp, #4 @ lr of instrumented routine (parent) + + @ called from __ftrace_regs_caller + ldr r1, [sp, #S_PC] @ instrumented routine (func) + mcount_adjust_addr r1, r1 + + mov r2, fp @ frame pointer + bl prepare_ftrace_return + + @ pop registers saved in ftrace_regs_caller + ldmia sp!, {r0-r12} @ restore r0 through r12 + ldr ip, [sp, #8] @ restore PC + ldr lr, [sp, #4] @ restore LR + ldr sp, [sp, #0] @ restore SP + mov pc, ip @ return + +.endm +#endif +#endif + .macro __ftrace_caller suffix mcount_enter mcount_get_lr r1 @ lr of instrumented func mcount_adjust_addr r0, lr @ instrumented function +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS + ldr r2, =function_trace_op + ldr r2, [r2] @ pointer to the current + @ function tracing op + mov r3, #0 @ regs is NULL +#endif + .globl ftrace_call\suffix ftrace_call\suffix: bl ftrace_stub @@ -212,6 +295,15 @@ UNWIND(.fnstart) __ftrace_caller UNWIND(.fnend) ENDPROC(ftrace_caller) + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +ENTRY(ftrace_regs_caller) +UNWIND(.fnstart) + __ftrace_regs_caller +UNWIND(.fnend) +ENDPROC(ftrace_regs_caller) +#endif + #endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -220,6 +312,14 @@ UNWIND(.fnstart) __ftrace_graph_caller UNWIND(.fnend) ENDPROC(ftrace_graph_caller) + +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS +ENTRY(ftrace_graph_regs_caller) +UNWIND(.fnstart) + __ftrace_graph_regs_caller +UNWIND(.fnend) +ENDPROC(ftrace_graph_regs_caller) +#endif #endif .purgem mcount_enter |