Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753752AbZJUOfo (ORCPT ); Wed, 21 Oct 2009 10:35:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753589AbZJUOfn (ORCPT ); Wed, 21 Oct 2009 10:35:43 -0400 Received: from mail-fx0-f218.google.com ([209.85.220.218]:64251 "EHLO mail-fx0-f218.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753724AbZJUOfk (ORCPT ); Wed, 21 Oct 2009 10:35:40 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=KG8qyhi8i1roH8FPuZsCeXBgjoQ115qurRb5MoFbpmis1tRdSyA205KkjvbggpA2v3 1nSjmfLau8zHoUhFkpc2Q1Z1FKgaSWSBc9Nsgb/n/k/NuhLDEsZUXmKLUibpXhVzjIHO UErtAavll+ZDTQnRyNLr1eeY+WjTwhZOKWT74= From: Wu Zhangjin To: linux-kernel@vger.kernel.org, linux-mips@linux-mips.org Cc: Wu Zhangjin , Thomas Gleixner , Ralf Baechle , Nicholas Mc Guire , Steven Rostedt , Wu Zhangjin Subject: [PATCH -v4 7/9] tracing: add dynamic function tracer support for MIPS Date: Wed, 21 Oct 2009 22:35:01 +0800 Message-Id: X-Mailer: git-send-email 1.6.2.1 In-Reply-To: <5dda13e8e3a9c9dba4bb7179183941bda502604f.1256135456.git.wuzhangjin@gmail.com> References: <028867b99ec532b84963a35e7d552becc783cafc.1256135456.git.wuzhangjin@gmail.com> <2f73eae542c47ac5bbb9f7280e6c0271d193e90d.1256135456.git.wuzhangjin@gmail.com> <3f0d3515f74a58f4cfd11e61b62a129fdc21e3a7.1256135456.git.wuzhangjin@gmail.com> <96110ea5dd4d3d54eb97d0bb708a5bd81c7a50b5.1256135456.git.wuzhangjin@gmail.com> <5dda13e8e3a9c9dba4bb7179183941bda502604f.1256135456.git.wuzhangjin@gmail.com> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7279 Lines: 275 dynamic function tracer need to replace "nop" to "jumps & links" and something reversely. in linux-mips64, there will be some local symbols, whose name are prefixed by $L, which need to be filtered. thanks goes to Steven for writing the mips64-specific function_regex. Signed-off-by: Wu Zhangjin --- arch/mips/Kconfig | 2 + arch/mips/include/asm/ftrace.h | 10 ++++ arch/mips/kernel/Makefile | 3 +- arch/mips/kernel/ftrace.c | 107 ++++++++++++++++++++++++++++++++++++++++ arch/mips/kernel/mcount.S | 31 ++++++++++++ scripts/recordmcount.pl | 22 ++++++++ 6 files changed, 174 insertions(+), 1 deletions(-) create mode 100644 arch/mips/kernel/ftrace.c diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index a9bd992..147fbbc 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -6,6 +6,8 @@ config MIPS select HAVE_ARCH_KGDB select HAVE_FUNCTION_TRACER select HAVE_FUNCTION_TRACE_MCOUNT_TEST + select HAVE_DYNAMIC_FTRACE + select HAVE_FTRACE_MCOUNT_RECORD # Horrible source of confusion. Die, die, die ... select EMBEDDED select RTC_LIB if !LEMOTE_FULOONG2E diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftrace.h index 5f8ebcf..b4970c9 100644 --- a/arch/mips/include/asm/ftrace.h +++ b/arch/mips/include/asm/ftrace.h @@ -19,6 +19,16 @@ extern void _mcount(void); #define mcount _mcount +#ifdef CONFIG_DYNAMIC_FTRACE +/* reloction of mcount call site is the same as the address */ +static inline unsigned long ftrace_call_adjust(unsigned long addr) +{ + return addr; +} + +struct dyn_arch_ftrace { +}; +#endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* __ASSEMBLY__ */ #endif /* CONFIG_FUNCTION_TRACER */ #endif /* _ASM_MIPS_FTRACE_H */ diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index 38e704a..3cda3ab 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -10,6 +10,7 @@ obj-y += cpu-probe.o branch.o entry.o genex.o irq.o process.o \ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_trace_clock.o = -pg +CFLAGS_REMOVE_ftrace.o = -pg CFLAGS_REMOVE_early_printk.o = -pg endif @@ -30,7 +31,7 @@ obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_MODULES) += mips_ksyms.o module.o obj-$(CONFIG_FTRACE) += trace_clock.o -obj-$(CONFIG_FUNCTION_TRACER) += mcount.o +obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o obj-$(CONFIG_CPU_LOONGSON2) += r4k_fpu.o r4k_switch.o obj-$(CONFIG_CPU_MIPS32) += r4k_fpu.o r4k_switch.o diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c new file mode 100644 index 0000000..1e44865 --- /dev/null +++ b/arch/mips/kernel/ftrace.c @@ -0,0 +1,107 @@ +/* + * Code for replacing ftrace calls with jumps. + * + * Copyright (C) 2007-2008 Steven Rostedt + * Copyright (C) 2009 DSLab, Lanzhou University, China + * Author: Wu Zhangjin + * + * Thanks goes to Steven Rostedt for writing the original x86 version. + */ + +#include +#include +#include + +#include + +#ifdef CONFIG_DYNAMIC_FTRACE + +#define JAL 0x0c000000 /* jump & link: ip --> ra, jump to target */ +#define ADDR_MASK 0x03ffffff /* op_code|addr : 31...26|25 ....0 */ + +#ifdef CONFIG_CPU_LOONGSON2 +static unsigned int ftrace_nop = 0x00020021; +#else +static unsigned int ftrace_nop = 0x00000000; +#endif + +static unsigned char *ftrace_call_replace(unsigned long op_code, + unsigned long addr) +{ + static unsigned int op; + + op = op_code | ((addr >> 2) & ADDR_MASK); + + return (unsigned char *)&op; +} + +static unsigned char *ftrace_nop_replace(void) +{ + return (unsigned char *)&ftrace_nop; +} + +static int +ftrace_modify_code(unsigned long ip, unsigned char *old_code, + unsigned char *new_code) +{ + unsigned char replaced[MCOUNT_INSN_SIZE]; + + /* read the text we want to modify */ + if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE)) + return -EFAULT; + + /* Make sure it is what we expect it to be */ + if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0) + return -EINVAL; + + /* replace the text with the new text */ + if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE)) + return -EPERM; + + flush_icache_range(ip, ip + 8); + + return 0; +} + +int ftrace_make_nop(struct module *mod, + struct dyn_ftrace *rec, unsigned long addr) +{ + unsigned char *new, *old; + + old = ftrace_call_replace(JAL, addr); + new = ftrace_nop_replace(); + + return ftrace_modify_code(rec->ip, old, new); +} + +int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) +{ + unsigned char *new, *old; + + old = ftrace_nop_replace(); + new = ftrace_call_replace(JAL, addr); + + return ftrace_modify_code(rec->ip, old, new); +} + +int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned long ip = (unsigned long)(&ftrace_call); + unsigned char old[MCOUNT_INSN_SIZE], *new; + int ret; + + memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE); + new = ftrace_call_replace(JAL, (unsigned long)func); + ret = ftrace_modify_code(ip, old, new); + + return ret; +} + +int __init ftrace_dyn_arch_init(void *data) +{ + /* The return code is retured via data */ + *(unsigned long *)data = 0; + + return 0; +} +#endif /* CONFIG_DYNAMIC_FTRACE */ diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index 82e54ab..30637e6 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -67,6 +67,35 @@ move ra, AT .endm +#ifdef CONFIG_DYNAMIC_FTRACE + +LEAF(_mcount) + RESTORE_SP_FOR_32BIT + RETURN_BACK + END(_mcount) + +NESTED(ftrace_caller, PT_SIZE, ra) + RESTORE_SP_FOR_32BIT + lw t0, function_trace_stop + bnez t0, ftrace_stub + nop + + MCOUNT_SAVE_REGS + + MCOUNT_SET_ARGS + .globl ftrace_call +ftrace_call: + jal ftrace_stub + nop + + MCOUNT_RESTORE_REGS + .globl ftrace_stub +ftrace_stub: + RETURN_BACK + END(ftrace_caller) + +#else /* ! CONFIG_DYNAMIC_FTRACE */ + NESTED(_mcount, PT_SIZE, ra) RESTORE_SP_FOR_32BIT lw t0, function_trace_stop @@ -94,5 +123,7 @@ ftrace_stub: RETURN_BACK END(_mcount) +#endif /* ! CONFIG_DYNAMIC_FTRACE */ + .set at .set reorder diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index daee038..511c3a2 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -245,6 +245,28 @@ if ($arch eq "x86_64") { $ld .= " -m elf64_sparc"; $cc .= " -m64"; $objcopy .= " -O elf64-sparc"; + +} elsif ($arch eq "mips") { + $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$"; + $objdump .= " -Melf-trad".$endian."mips "; + + if ($endian eq "big") { + $endian = " -EB "; + $ld .= " -melf".$bits."btsmip"; + } else { + $endian = " -EL "; + $ld .= " -melf".$bits."ltsmip"; + } + + $cc .= " -mno-abicalls -fno-pic -mabi=" . $bits . $endian; + $ld .= $endian; + + if ($bits == 64) { + $function_regex = + "^([0-9a-fA-F]+)\\s+<(.|[^\$]L.*?|\$[^L].*?|[^\$][^L].*?)>:"; + $type = ".dword"; + } + } else { die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD"; } -- 1.6.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/