diff options
Diffstat (limited to 'arch/blackfin/kernel')
| -rw-r--r-- | arch/blackfin/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/blackfin/kernel/ftrace-entry.S | 85 | ||||
| -rw-r--r-- | arch/blackfin/kernel/ftrace.c | 86 |
3 files changed, 163 insertions, 9 deletions
diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile index 30d0d1f01dc7..ca5ccc777772 100644 --- a/arch/blackfin/kernel/Makefile +++ b/arch/blackfin/kernel/Makefile @@ -16,6 +16,7 @@ else obj-y += time.o endif +obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_FUNCTION_TRACER) += ftrace-entry.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o CFLAGS_REMOVE_ftrace.o = -pg diff --git a/arch/blackfin/kernel/ftrace-entry.S b/arch/blackfin/kernel/ftrace-entry.S index d66446b572c0..7eed00bbd26d 100644 --- a/arch/blackfin/kernel/ftrace-entry.S +++ b/arch/blackfin/kernel/ftrace-entry.S @@ -10,6 +10,18 @@ .text +#ifdef CONFIG_DYNAMIC_FTRACE + +/* Simple stub so we can boot the kernel until runtime patching has + * disabled all calls to this. Then it'll be unused. + */ +ENTRY(__mcount) +# if ANOMALY_05000371 + nop; nop; nop; nop; +# endif + rts; +ENDPROC(__mcount) + /* GCC will have called us before setting up the function prologue, so we * can clobber the normal scratch registers, but we need to make sure to * save/restore the registers used for argument passing (R0-R2) in case @@ -20,15 +32,65 @@ * function. And since GCC pushed the previous RETS for us, the previous * function will be waiting there. mmmm pie. */ +ENTRY(_ftrace_caller) +# ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST + /* optional micro optimization: return if stopped */ + p1.l = _function_trace_stop; + p1.h = _function_trace_stop; + r3 = [p1]; + cc = r3 == 0; + if ! cc jump _ftrace_stub (bp); +# endif + + /* save first/second/third function arg and the return register */ + [--sp] = r2; + [--sp] = r0; + [--sp] = r1; + [--sp] = rets; + + /* function_trace_call(unsigned long ip, unsigned long parent_ip): + * ip: this point was called by ... + * parent_ip: ... this function + * the ip itself will need adjusting for the mcount call + */ + r0 = rets; + r1 = [sp + 16]; /* skip the 4 local regs on stack */ + r0 += -MCOUNT_INSN_SIZE; + +.globl _ftrace_call +_ftrace_call: + call _ftrace_stub + +# ifdef CONFIG_FUNCTION_GRAPH_TRACER +.globl _ftrace_graph_call +_ftrace_graph_call: + nop; /* jump _ftrace_graph_caller; */ +# endif + + /* restore state and get out of dodge */ +.Lfinish_trace: + rets = [sp++]; + r1 = [sp++]; + r0 = [sp++]; + r2 = [sp++]; + +.globl _ftrace_stub +_ftrace_stub: + rts; +ENDPROC(_ftrace_caller) + +#else + +/* See documentation for _ftrace_caller */ ENTRY(__mcount) -#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST +# ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST /* optional micro optimization: return if stopped */ p1.l = _function_trace_stop; p1.h = _function_trace_stop; r3 = [p1]; cc = r3 == 0; if ! cc jump _ftrace_stub (bp); -#endif +# endif /* save third function arg early so we can do testing below */ [--sp] = r2; @@ -44,7 +106,7 @@ ENTRY(__mcount) cc = r2 == r3; if ! cc jump .Ldo_trace; -#ifdef CONFIG_FUNCTION_GRAPH_TRACER +# ifdef CONFIG_FUNCTION_GRAPH_TRACER /* if the ftrace_graph_return function pointer is not set to * the ftrace_stub entry, call prepare_ftrace_return(). */ @@ -64,7 +126,7 @@ ENTRY(__mcount) r3 = [p0]; cc = r2 == r3; if ! cc jump _ftrace_graph_caller; -#endif +# endif r2 = [sp++]; rts; @@ -103,6 +165,8 @@ _ftrace_stub: rts; ENDPROC(__mcount) +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* The prepare_ftrace_return() function is similar to the trace function * except it takes a pointer to the location of the frompc. This is so @@ -110,6 +174,7 @@ ENDPROC(__mcount) * purposes. */ ENTRY(_ftrace_graph_caller) +# ifndef CONFIG_DYNAMIC_FTRACE /* save first/second function arg and the return register */ [--sp] = r0; [--sp] = r1; @@ -118,9 +183,13 @@ ENTRY(_ftrace_graph_caller) /* prepare_ftrace_return(parent, self_addr, frame_pointer) */ r0 = sp; /* unsigned long *parent */ r1 = rets; /* unsigned long self_addr */ -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST +# else + r0 = sp; /* unsigned long *parent */ + r1 = [sp]; /* unsigned long self_addr */ +# endif +# ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST r2 = fp; /* unsigned long frame_pointer */ -#endif +# endif r0 += 16; /* skip the 4 local regs on stack */ r1 += -MCOUNT_INSN_SIZE; call _prepare_ftrace_return; @@ -139,9 +208,9 @@ ENTRY(_return_to_handler) [--sp] = r1; /* get original return address */ -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST +# ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST r0 = fp; /* Blackfin is sane, so omit this */ -#endif +# endif call _ftrace_return_to_handler; rets = r0; diff --git a/arch/blackfin/kernel/ftrace.c b/arch/blackfin/kernel/ftrace.c index a61d948ea925..48808a12b427 100644 --- a/arch/blackfin/kernel/ftrace.c +++ b/arch/blackfin/kernel/ftrace.c @@ -1,17 +1,101 @@ /* * ftrace graph code * - * Copyright (C) 2009 Analog Devices Inc. + * Copyright (C) 2009-2010 Analog Devices Inc. * Licensed under the GPL-2 or later. */ #include <linux/ftrace.h> #include <linux/kernel.h> #include <linux/sched.h> +#include <linux/uaccess.h> #include <asm/atomic.h> +#include <asm/cacheflush.h> + +#ifdef CONFIG_DYNAMIC_FTRACE + +static const unsigned char mnop[] = { + 0x03, 0xc0, 0x00, 0x18, /* MNOP; */ + 0x03, 0xc0, 0x00, 0x18, /* MNOP; */ +}; + +static void bfin_make_pcrel24(unsigned char *insn, unsigned long src, + unsigned long dst) +{ + uint32_t pcrel = (dst - src) >> 1; + insn[0] = pcrel >> 16; + insn[1] = 0xe3; + insn[2] = pcrel; + insn[3] = pcrel >> 8; +} +#define bfin_make_pcrel24(insn, src, dst) bfin_make_pcrel24(insn, src, (unsigned long)(dst)) + +static int ftrace_modify_code(unsigned long ip, const unsigned char *code, + unsigned long len) +{ + int ret = probe_kernel_write((void *)ip, (void *)code, len); + flush_icache_range(ip, ip + len); + return ret; +} + +int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, + unsigned long addr) +{ + /* Turn the mcount call site into two MNOPs as those are 32bit insns */ + return ftrace_modify_code(rec->ip, mnop, sizeof(mnop)); +} + +int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) +{ + /* Restore the mcount call site */ + unsigned char call[8]; + call[0] = 0x67; /* [--SP] = RETS; */ + call[1] = 0x01; + bfin_make_pcrel24(&call[2], rec->ip + 2, addr); + call[6] = 0x27; /* RETS = [SP++]; */ + call[7] = 0x01; + return ftrace_modify_code(rec->ip, call, sizeof(call)); +} + +int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned char call[4]; + unsigned long ip = (unsigned long)&ftrace_call; + bfin_make_pcrel24(call, ip, func); + return ftrace_modify_code(ip, call, sizeof(call)); +} + +int __init ftrace_dyn_arch_init(void *data) +{ + /* return value is done indirectly via data */ + *(unsigned long *)data = 0; + + return 0; +} + +#endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER +# ifdef CONFIG_DYNAMIC_FTRACE + +extern void ftrace_graph_call(void); + +int ftrace_enable_ftrace_graph_caller(void) +{ + unsigned long ip = (unsigned long)&ftrace_graph_call; + uint16_t jump_pcrel12 = ((unsigned long)&ftrace_graph_caller - ip) >> 1; + jump_pcrel12 |= 0x2000; + return ftrace_modify_code(ip, (void *)&jump_pcrel12, sizeof(jump_pcrel12)); +} + +int ftrace_disable_ftrace_graph_caller(void) +{ + return ftrace_modify_code((unsigned long)&ftrace_graph_call, empty_zero_page, 2); +} + +# endif + /* * Hook the return address and push it in the stack of return addrs * in current thread info. |