Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754549AbZKNGgO (ORCPT ); Sat, 14 Nov 2009 01:36:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754209AbZKNGgL (ORCPT ); Sat, 14 Nov 2009 01:36:11 -0500 Received: from mail-pw0-f42.google.com ([209.85.160.42]:62298 "EHLO mail-pw0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754466AbZKNGgG (ORCPT ); Sat, 14 Nov 2009 01:36:06 -0500 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=kMl5o2cMlodMKzqxKqowhH0GJUiTy9k6b14ePVXLsUOA+1rkO59XRs635t6IufEn8N Y8kBwtdwKT8f5oEris2tktSJGGl7lEtPOpvp2D4U8uJLqBWhXiZxdNZMpg/SDd3K5XX4 Wz2ViZJ1UVQVFh2/ON0gNg2W6lHLKC4fa52hQ= From: Wu Zhangjin To: rostedt@goodmis.org, Ralf Baechle Cc: Wu Zhangjin , Frederic Weisbecker , Ingo Molnar , Nicholas Mc Guire , David Daney , Richard Sandiford , Patrik Kluba , Thomas Gleixner , Michal Simek , "Maciej W . Rozycki" , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, zhangfx@lemote.com, zhouqg@gmail.com Subject: [PATCH v8 14/16] tracing: make ftrace for MIPS work without -fno-omit-frame-pointer Date: Sat, 14 Nov 2009 14:33:29 +0800 Message-Id: <24733f375d853dd6dc44138c53f2f57493915d8f.1258177321.git.wuzhangjin@gmail.com> X-Mailer: git-send-email 1.6.2.1 In-Reply-To: References: <9dc81a7a9e5a292cccdf465c533a2b08d19d6021.1258177321.git.wuzhangjin@gmail.com> <8f579e2cece16cd22358a4ec143ef6a8c462639b.1258177321.git.wuzhangjin@gmail.com> <7c7568247ad6cc109ec20387cfc3ca258d1d430f.1258177321.git.wuzhangjin@gmail.com> <3fcaffcfb3c8c8cd3015151ed5b7480ccaecde0f.1258177321.git.wuzhangjin@gmail.com> <48676d84140dbafd46e530611766121e18abc4ef.1258177321.git.wuzhangjin@gmail.com> <99ebd8fcb19e4cccd702fca966405ffc45f8540b.1258177321.git.wuzhangjin@gmail.com> <8a7987bba58526a0e156f531dba31d9a65d3d744.1258177321.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: 6847 Lines: 246 From: Wu Zhangjin When remove the -fno-omit-frame-pointer, gcc will not save the frame pointer for us, we need to save one ourselves. Signed-off-by: Wu Zhangjin --- arch/mips/include/asm/ftrace.h | 57 ++++++++++++++++++++++++++++++++++++++++ arch/mips/kernel/ftrace.c | 56 ++++++++++++++++++++++++++++---------- arch/mips/kernel/mcount.S | 8 +++++ 3 files changed, 106 insertions(+), 15 deletions(-) diff --git a/arch/mips/include/asm/ftrace.h b/arch/mips/include/asm/ftrace.h index aa7c80b..f78d763 100644 --- a/arch/mips/include/asm/ftrace.h +++ b/arch/mips/include/asm/ftrace.h @@ -19,6 +19,62 @@ extern void _mcount(void); #define mcount _mcount +#define safe_load(load, src, dst, error) \ +do { \ + asm volatile ( \ + "1: " load " %[" STR(dst) "], 0(%[" STR(src) "])\n"\ + " li %[" STR(error) "], 0\n" \ + "2:\n" \ + \ + ".section .fixup, \"ax\"\n" \ + "3: li %[" STR(error) "], 1\n" \ + " j 2b\n" \ + ".previous\n" \ + \ + ".section\t__ex_table,\"a\"\n\t" \ + STR(PTR) "\t1b, 3b\n\t" \ + ".previous\n" \ + \ + : [dst] "=&r" (dst), [error] "=r" (error)\ + : [src] "r" (src) \ + : "memory" \ + ); \ +} while (0) + +#define safe_store(store, src, dst, error) \ +do { \ + asm volatile ( \ + "1: " store " %[" STR(src) "], 0(%[" STR(dst) "])\n"\ + " li %[" STR(error) "], 0\n" \ + "2:\n" \ + \ + ".section .fixup, \"ax\"\n" \ + "3: li %[" STR(error) "], 1\n" \ + " j 2b\n" \ + ".previous\n" \ + \ + ".section\t__ex_table,\"a\"\n\t"\ + STR(PTR) "\t1b, 3b\n\t" \ + ".previous\n" \ + \ + : [error] "=r" (error) \ + : [dst] "r" (dst), [src] "r" (src)\ + : "memory" \ + ); \ +} while (0) + +#define safe_load_code(dst, src, error) \ + safe_load(STR(lw), src, dst, error) +#define safe_store_code(src, dst, error) \ + safe_store(STR(sw), src, dst, error) + +#define safe_load_stack(dst, src, error) \ + safe_load(STR(PTR_L), src, dst, error) + +#define safe_store_stack(src, dst, error) \ + safe_store(STR(PTR_S), src, dst, error) + + #ifdef CONFIG_DYNAMIC_FTRACE static inline unsigned long ftrace_call_adjust(unsigned long addr) { @@ -27,6 +83,7 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr) struct dyn_arch_ftrace { }; + #endif /* CONFIG_DYNAMIC_FTRACE */ /* not trace the timecounter_read* in kernel/time/clocksource.c */ diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index e981a49..e363fc6 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -27,7 +27,13 @@ static unsigned int ftrace_nop = 0x00000000; static int ftrace_modify_code(unsigned long ip, unsigned int new_code) { - *(unsigned int *)ip = new_code; + int faulted; + + /* *(unsigned int *)ip = new_code; */ + safe_store_code(new_code, ip, faulted); + + if (unlikely(faulted)) + return -EFAULT; flush_icache_range(ip, ip + 8); @@ -41,14 +47,20 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { unsigned int new; + int faulted; unsigned long ip = rec->ip; /* We have compiled module with -mlong-calls, but compiled the kernel * without it, we need to cope with them respectively. */ if (ip & 0x40000000) { /* record it for ftrace_make_call */ - if (lui_v1 == 0) - lui_v1 = *(unsigned int *)ip; + if (lui_v1 == 0) { + /* lui_v1 = *(unsigned int *)ip; */ + safe_load_code(lui_v1, ip, faulted); + + if (unlikely(faulted)) + return -EFAULT; + } /* lui v1, hi_16bit_of_mcount --> b 1f (0x10000004) * addiu v1, v1, low_16bit_of_mcount @@ -147,6 +159,7 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr, { unsigned long sp, ip, ra; unsigned int code; + int faulted; /* in module or kernel? */ if (self_addr & 0x40000000) { @@ -162,8 +175,11 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr, do { ip -= 4; - /* get the code at "ip" */ - code = *(unsigned int *)ip; + /* get the code at "ip": code = *(unsigned int *)ip; */ + safe_load_code(code, ip, faulted); + + if (unlikely(faulted)) + return 0; /* If we hit the non-store instruction before finding where the * ra is stored, then this is a leaf function and it does not @@ -174,11 +190,14 @@ unsigned long ftrace_get_parent_addr(unsigned long self_addr, } while (((code & S_RA_SP) != S_RA_SP)); sp = fp + (code & OFFSET_MASK); - ra = *(unsigned long *)sp; + + /* ra = *(unsigned long *)sp; */ + safe_load_stack(ra, sp, faulted); + if (unlikely(faulted)) + return 0; if (ra == parent) return sp; - return 0; } @@ -193,6 +212,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, struct ftrace_graph_ent trace; unsigned long return_hooker = (unsigned long) &return_to_handler; + int faulted; if (unlikely(atomic_read(¤t->tracing_graph_pause))) return; @@ -206,21 +226,23 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, * ftrace_get_parent_addr() does it! */ - old = *parent; + /* old = *parent; */ + safe_load_stack(old, parent, faulted); + if (unlikely(faulted)) + goto out; parent = (unsigned long *)ftrace_get_parent_addr(self_addr, old, (unsigned long)parent, fp); - /* If fails when getting the stack address of the non-leaf function's * ra, stop function graph tracer and return */ - if (parent == 0) { - ftrace_graph_stop(); - WARN_ON(1); - return; - } + if (parent == 0) + goto out; - *parent = return_hooker; + /* *parent = return_hooker; */ + safe_store_stack(return_hooker, parent, faulted); + if (unlikely(faulted)) + goto out; if (ftrace_push_return_trace(old, self_addr, &trace.depth, fp) == -EBUSY) { @@ -235,5 +257,9 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, current->curr_ret_stack--; *parent = old; } + return; +out: + ftrace_graph_stop(); + WARN_ON(1); } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S index 98d4690..bdfef2c 100644 --- a/arch/mips/kernel/mcount.S +++ b/arch/mips/kernel/mcount.S @@ -139,7 +139,15 @@ NESTED(ftrace_graph_caller, PT_SIZE, ra) #endif PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */ jal prepare_ftrace_return +#ifdef CONFIG_FRAME_POINTER move a2, fp /* arg3: frame pointer */ +#else +#ifdef CONFIG_64BIT + PTR_LA a2, PT_SIZE(sp) +#else + PTR_LA a2, (PT_SIZE+8)(sp) +#endif +#endif MCOUNT_RESTORE_REGS RETURN_BACK -- 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/