From c513867561eeb07d24a0bdda1a18a8f91921a301 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 14 Oct 2008 18:08:48 -0400 Subject: ftrace: do not enclose logic in WARN_ON In ftrace, logic is defined in the WARN_ON_ONCE, which can become a nop with some configs. This patch fixes it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index d073d981a73..8821ceabf51 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -62,6 +62,7 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code) { unsigned char replaced[MCOUNT_INSN_SIZE]; + int ret; /* * Note: Due to modules and __init, code can @@ -77,8 +78,9 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0) return 2; - WARN_ON_ONCE(__copy_to_user_inatomic((char __user *)ip, new_code, - MCOUNT_INSN_SIZE)); + ret = __copy_to_user_inatomic((char __user *)ip, new_code, + MCOUNT_INSN_SIZE); + WARN_ON_ONCE(ret); sync_core(); -- cgit v1.2.3 From 606576ce816603d9fe1fb453a88bc6eea16ca709 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 6 Oct 2008 19:06:12 -0400 Subject: ftrace: rename FTRACE to FUNCTION_TRACER Due to confusion between the ftrace infrastructure and the gcc profiling tracer "ftrace", this patch renames the config options from FTRACE to FUNCTION_TRACER. The other two names that are offspring from FTRACE DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same. This patch was generated mostly by script, and partially by hand. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/Makefile | 2 +- arch/x86/kernel/entry_32.S | 4 ++-- arch/x86/kernel/entry_64.S | 4 ++-- arch/x86/kernel/i386_ksyms_32.c | 2 +- arch/x86/kernel/x8664_ksyms_64.c | 2 +- 5 files changed, 7 insertions(+), 7 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 0d41f0343dc..ec3d30136bf 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -6,7 +6,7 @@ extra-y := head_$(BITS).o head$(BITS).o head.o init_task.o vmlinu CPPFLAGS_vmlinux.lds += -U$(UTS_MACHINE) -ifdef CONFIG_FTRACE +ifdef CONFIG_FUNCTION_TRACER # Do not profile debug and lowlevel utilities CFLAGS_REMOVE_tsc.o = -pg CFLAGS_REMOVE_rtc.o = -pg diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 4e4269c73bb..9d49facc21f 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -1149,7 +1149,7 @@ ENDPROC(xen_failsafe_callback) #endif /* CONFIG_XEN */ -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) @@ -1204,7 +1204,7 @@ trace: jmp ftrace_stub END(mcount) #endif /* CONFIG_DYNAMIC_FTRACE */ -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ .section .rodata,"a" #include "syscall_table_32.S" diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 09e7145484c..b86f332c96a 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -61,7 +61,7 @@ .code64 -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(mcount) retq @@ -138,7 +138,7 @@ trace: jmp ftrace_stub END(mcount) #endif /* CONFIG_DYNAMIC_FTRACE */ -#endif /* CONFIG_FTRACE */ +#endif /* CONFIG_FUNCTION_TRACER */ #ifndef CONFIG_PREEMPT #define retint_kernel retint_restore_args diff --git a/arch/x86/kernel/i386_ksyms_32.c b/arch/x86/kernel/i386_ksyms_32.c index dd7ebee446a..43cec6bdda6 100644 --- a/arch/x86/kernel/i386_ksyms_32.c +++ b/arch/x86/kernel/i386_ksyms_32.c @@ -5,7 +5,7 @@ #include #include -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* mcount is defined in assembly */ EXPORT_SYMBOL(mcount); #endif diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index b545f371b5f..695e426aa35 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -12,7 +12,7 @@ #include #include -#ifdef CONFIG_FTRACE +#ifdef CONFIG_FUNCTION_TRACER /* mcount is defined in assembly */ EXPORT_SYMBOL(mcount); #endif -- cgit v1.2.3 From 593eb8a2d63e95772a5f22d746f18a997c5ee463 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:32:59 -0400 Subject: ftrace: return error on failed modified text. Have the ftrace_modify_code return error values: -EFAULT on error of reading the address -EINVAL if what is read does not match what it expected -EPERM if the write fails to update after a successful match. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 8821ceabf51..428291581cb 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -62,7 +62,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code) { unsigned char replaced[MCOUNT_INSN_SIZE]; - int ret; /* * Note: Due to modules and __init, code can @@ -72,15 +71,16 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, * No real locking needed, this code is run through * kstop_machine, or before SMP starts. */ - if (__copy_from_user_inatomic(replaced, (char __user *)ip, MCOUNT_INSN_SIZE)) - return 1; + if (__copy_from_user_inatomic(replaced, (char __user *)ip, + MCOUNT_INSN_SIZE)) + return -EFAULT; if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0) - return 2; + return -EINVAL; - ret = __copy_to_user_inatomic((char __user *)ip, new_code, - MCOUNT_INSN_SIZE); - WARN_ON_ONCE(ret); + if (__copy_to_user_inatomic((char __user *)ip, new_code, + MCOUNT_INSN_SIZE)) + return -EPERM; sync_core(); -- cgit v1.2.3 From 76aefee57657428fb77cbd8624119c1a440bee44 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:00 -0400 Subject: ftrace: comment arch ftrace code Add comments to explain what is happening in the x86 arch ftrace code. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 428291581cb..783455454d7 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -66,18 +66,23 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, /* * Note: Due to modules and __init, code can * disappear and change, we need to protect against faulting - * as well as code changing. + * as well as code changing. We do this by using the + * __copy_*_user functions. * * No real locking needed, this code is run through * kstop_machine, or before SMP starts. */ + + /* read the text we want to modify */ if (__copy_from_user_inatomic(replaced, (char __user *)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 (__copy_to_user_inatomic((char __user *)ip, new_code, MCOUNT_INSN_SIZE)) return -EPERM; -- cgit v1.2.3 From ab9a0918cbf0fa8883301838df8dbc8fc085ff50 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:01 -0400 Subject: ftrace: use probe_kernel Andrew Morton suggested using the proper API for reading and writing kernel areas that might fault. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 783455454d7..da4fb0deecf 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -67,15 +67,14 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, * Note: Due to modules and __init, code can * disappear and change, we need to protect against faulting * as well as code changing. We do this by using the - * __copy_*_user functions. + * probe_kernel_* functions. * * No real locking needed, this code is run through * kstop_machine, or before SMP starts. */ /* read the text we want to modify */ - if (__copy_from_user_inatomic(replaced, (char __user *)ip, - MCOUNT_INSN_SIZE)) + if (probe_kernel_read(replaced, (void *)ip, MCOUNT_INSN_SIZE)) return -EFAULT; /* Make sure it is what we expect it to be */ @@ -83,8 +82,7 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, return -EINVAL; /* replace the text with the new text */ - if (__copy_to_user_inatomic((char __user *)ip, new_code, - MCOUNT_INSN_SIZE)) + if (probe_kernel_write((void *)ip, new_code, MCOUNT_INSN_SIZE)) return -EPERM; sync_core(); -- cgit v1.2.3 From 4d296c24326783bff1282ac72f310d8bac8df413 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:06 -0400 Subject: ftrace: remove mcount set The arch dependent function ftrace_mcount_set was only used by the daemon start up code. This patch removes it. Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index da4fb0deecf..b399eed2353 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -103,13 +103,6 @@ notrace int ftrace_update_ftrace_func(ftrace_func_t func) return ret; } -notrace int ftrace_mcount_set(unsigned long *data) -{ - /* mcount is initialized as a nop */ - *data = 0; - return 0; -} - int __init ftrace_dyn_arch_init(void *data) { extern const unsigned char ftrace_test_p6nop[]; -- cgit v1.2.3 From 15adc048986f6b54b6044f2b6fc4b48f49413e2f Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Thu, 23 Oct 2008 09:33:08 -0400 Subject: ftrace, powerpc, sparc64, x86: remove notrace from arch ftrace file The entire file of ftrace.c in the arch code needs to be marked as notrace. It is much cleaner to do this from the Makefile with CFLAGS_REMOVE_ftrace.o. [ powerpc already had this in its Makefile. ] Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/Makefile | 1 + arch/x86/kernel/ftrace.c | 10 +++++----- 2 files changed, 6 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index f1283fe6072..e489ff9cb3e 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -11,6 +11,7 @@ ifdef CONFIG_FUNCTION_TRACER CFLAGS_REMOVE_tsc.o = -pg CFLAGS_REMOVE_rtc.o = -pg CFLAGS_REMOVE_paravirt-spinlocks.o = -pg +CFLAGS_REMOVE_ftrace.o = -pg endif # diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index b399eed2353..b1e5e2244ec 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -33,17 +33,17 @@ union ftrace_code_union { }; -static int notrace ftrace_calc_offset(long ip, long addr) +static int ftrace_calc_offset(long ip, long addr) { return (int)(addr - ip); } -notrace unsigned char *ftrace_nop_replace(void) +unsigned char *ftrace_nop_replace(void) { return (char *)ftrace_nop; } -notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) +unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) { static union ftrace_code_union calc; @@ -57,7 +57,7 @@ notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) return calc.code; } -notrace int +int ftrace_modify_code(unsigned long ip, unsigned char *old_code, unsigned char *new_code) { @@ -90,7 +90,7 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code, return 0; } -notrace int ftrace_update_ftrace_func(ftrace_func_t func) +int ftrace_update_ftrace_func(ftrace_func_t func) { unsigned long ip = (unsigned long)(&ftrace_call); unsigned char old[MCOUNT_INSN_SIZE], *new; -- cgit v1.2.3 From 8115f3f0c939c5db0fe3c6c6c58911fd3a205b1e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 24 Oct 2008 09:12:17 -0400 Subject: ftrace: use a real variable for ftrace_nop in x86 Impact: avoid section mismatch warning, clean up The dynamic ftrace determines which nop is safe to use at start up. When it finds a safe nop for patching, it sets a pointer called ftrace_nop to point to the code. All call sites are then patched to this nop. Later, when tracing is turned on, this ftrace_nop variable is again used to compare the location to make sure it is a nop before we update it to an mcount call. If this fails just once, a warning is printed and ftrace is disabled. Rakib Mullick noted that the code that sets up the nop is a .init section where as the nop itself is in the .text section. This is needed because the nop is used later on after boot up. The problem is that the test of the nop jumps back to the setup code and causes a "section mismatch" warning. Rakib first recommended to convert the nop to .init.text, but as stated above, this would fail since that text is used later. The real solution is to extend Rabik's patch, and to make the ftrace_nop into an array, and just save the code from the assembly to this array. Now the section can stay as an init section, and we have a nop to use later on. Reported-by: Rakib Mullick Signed-off-by: Steven Rostedt Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) (limited to 'arch/x86/kernel') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index b1e5e2244ec..50ea0ac8c9b 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -21,8 +21,7 @@ #include -/* Long is fine, even if it is only 4 bytes ;-) */ -static unsigned long *ftrace_nop; +static unsigned char ftrace_nop[MCOUNT_INSN_SIZE]; union ftrace_code_union { char code[MCOUNT_INSN_SIZE]; @@ -40,7 +39,7 @@ static int ftrace_calc_offset(long ip, long addr) unsigned char *ftrace_nop_replace(void) { - return (char *)ftrace_nop; + return ftrace_nop; } unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr) @@ -125,9 +124,6 @@ int __init ftrace_dyn_arch_init(void *data) * TODO: check the cpuid to determine the best nop. */ asm volatile ( - "jmp ftrace_test_jmp\n" - /* This code needs to stay around */ - ".section .text, \"ax\"\n" "ftrace_test_jmp:" "jmp ftrace_test_p6nop\n" "nop\n" @@ -138,8 +134,6 @@ int __init ftrace_dyn_arch_init(void *data) "jmp 1f\n" "ftrace_test_nop5:" ".byte 0x66,0x66,0x66,0x66,0x90\n" - "jmp 1f\n" - ".previous\n" "1:" ".section .fixup, \"ax\"\n" "2: movl $1, %0\n" @@ -154,15 +148,15 @@ int __init ftrace_dyn_arch_init(void *data) switch (faulted) { case 0: pr_info("ftrace: converting mcount calls to 0f 1f 44 00 00\n"); - ftrace_nop = (unsigned long *)ftrace_test_p6nop; + memcpy(ftrace_nop, ftrace_test_p6nop, MCOUNT_INSN_SIZE); break; case 1: pr_info("ftrace: converting mcount calls to 66 66 66 66 90\n"); - ftrace_nop = (unsigned long *)ftrace_test_nop5; + memcpy(ftrace_nop, ftrace_test_nop5, MCOUNT_INSN_SIZE); break; case 2: pr_info("ftrace: converting mcount calls to jmp . + 5\n"); - ftrace_nop = (unsigned long *)ftrace_test_jmp; + memcpy(ftrace_nop, ftrace_test_jmp, MCOUNT_INSN_SIZE); break; } -- cgit v1.2.3