From 3bb258bf430d29a24350fe4f44f8bf07b7b7a8f6 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Sun, 4 Oct 2009 17:53:29 -0700 Subject: ftrace.c: Add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - Remove prefixes from pr_, use pr_fmt(fmt). No change in output. Signed-off-by: Joe Perches Acked-by: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <9b377eefae9e28c599dd4a17bdc81172965e9931.1254701151.git.joe@perches.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/ftrace.c') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 9dbb527e1652..25e6f5fc4b1e 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -9,6 +9,8 @@ * the dangers of modifying code on the run. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -336,15 +338,15 @@ 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"); + pr_info("converting mcount calls to 0f 1f 44 00 00\n"); 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"); + pr_info("converting mcount calls to 66 66 66 66 90\n"); memcpy(ftrace_nop, ftrace_test_nop5, MCOUNT_INSN_SIZE); break; case 2: - pr_info("ftrace: converting mcount calls to jmp . + 5\n"); + pr_info("converting mcount calls to jmp . + 5\n"); memcpy(ftrace_nop, ftrace_test_jmp, MCOUNT_INSN_SIZE); break; } -- cgit v1.2.3 From c44fc770845163f8d9e573f37f92a7b7a7ade14e Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 19 Sep 2009 06:50:42 +0200 Subject: tracing: Move syscalls metadata handling from arch to core Most of the syscalls metadata processing is done from arch. But these operations are mostly generic accross archs. Especially now that we have a common variable name that expresses the number of syscalls supported by an arch: NR_syscalls, the only remaining bits that need to reside in arch is the syscall nr to addr translation. v2: Compare syscalls symbols only after the "sys" prefix so that we avoid spurious mismatches with archs that have syscalls wrappers, in which case syscalls symbols have "SyS" prefixed aliases. (Reported by: Heiko Carstens) Signed-off-by: Frederic Weisbecker Acked-by: Heiko Carstens Cc: Ingo Molnar Cc: Steven Rostedt Cc: Li Zefan Cc: Masami Hiramatsu Cc: Jason Baron Cc: Lai Jiangshan Cc: Martin Schwidefsky Cc: Paul Mundt --- arch/s390/kernel/ftrace.c | 67 +-------------------------------- arch/x86/kernel/ftrace.c | 76 +------------------------------------- include/trace/syscall.h | 2 +- kernel/trace/trace_syscalls.c | 86 +++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 91 insertions(+), 140 deletions(-) (limited to 'arch/x86/kernel/ftrace.c') diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index 57bdcb1e3cdf..7c5752c3423d 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -206,73 +206,10 @@ out: #ifdef CONFIG_FTRACE_SYSCALLS -extern unsigned long __start_syscalls_metadata[]; -extern unsigned long __stop_syscalls_metadata[]; extern unsigned int sys_call_table[]; -static struct syscall_metadata **syscalls_metadata; - -struct syscall_metadata *syscall_nr_to_meta(int nr) -{ - if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) - return NULL; - - return syscalls_metadata[nr]; -} - -int syscall_name_to_nr(char *name) -{ - int i; - - if (!syscalls_metadata) - return -1; - for (i = 0; i < NR_syscalls; i++) - if (syscalls_metadata[i]) - if (!strcmp(syscalls_metadata[i]->name, name)) - return i; - return -1; -} - -void set_syscall_enter_id(int num, int id) -{ - syscalls_metadata[num]->enter_id = id; -} - -void set_syscall_exit_id(int num, int id) +unsigned long __init arch_syscall_addr(int nr) { - syscalls_metadata[num]->exit_id = id; -} - -static struct syscall_metadata *find_syscall_meta(unsigned long syscall) -{ - struct syscall_metadata *start; - struct syscall_metadata *stop; - char str[KSYM_SYMBOL_LEN]; - - start = (struct syscall_metadata *)__start_syscalls_metadata; - stop = (struct syscall_metadata *)__stop_syscalls_metadata; - kallsyms_lookup(syscall, NULL, NULL, NULL, str); - - for ( ; start < stop; start++) { - if (start->name && !strcmp(start->name + 3, str + 3)) - return start; - } - return NULL; -} - -static int __init arch_init_ftrace_syscalls(void) -{ - struct syscall_metadata *meta; - int i; - syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * NR_syscalls, - GFP_KERNEL); - if (!syscalls_metadata) - return -ENOMEM; - for (i = 0; i < NR_syscalls; i++) { - meta = find_syscall_meta((unsigned long)sys_call_table[i]); - syscalls_metadata[i] = meta; - } - return 0; + return (unsigned long)sys_call_table[nr]; } -arch_initcall(arch_init_ftrace_syscalls); #endif diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 25e6f5fc4b1e..5a1b9758fd62 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -470,82 +470,10 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, #ifdef CONFIG_FTRACE_SYSCALLS -extern unsigned long __start_syscalls_metadata[]; -extern unsigned long __stop_syscalls_metadata[]; extern unsigned long *sys_call_table; -static struct syscall_metadata **syscalls_metadata; - -static struct syscall_metadata *find_syscall_meta(unsigned long *syscall) -{ - struct syscall_metadata *start; - struct syscall_metadata *stop; - char str[KSYM_SYMBOL_LEN]; - - - start = (struct syscall_metadata *)__start_syscalls_metadata; - stop = (struct syscall_metadata *)__stop_syscalls_metadata; - kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str); - - for ( ; start < stop; start++) { - if (start->name && !strcmp(start->name, str)) - return start; - } - return NULL; -} - -struct syscall_metadata *syscall_nr_to_meta(int nr) -{ - if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) - return NULL; - - return syscalls_metadata[nr]; -} - -int syscall_name_to_nr(char *name) -{ - int i; - - if (!syscalls_metadata) - return -1; - - for (i = 0; i < NR_syscalls; i++) { - if (syscalls_metadata[i]) { - if (!strcmp(syscalls_metadata[i]->name, name)) - return i; - } - } - return -1; -} - -void set_syscall_enter_id(int num, int id) -{ - syscalls_metadata[num]->enter_id = id; -} - -void set_syscall_exit_id(int num, int id) +unsigned long __init arch_syscall_addr(int nr) { - syscalls_metadata[num]->exit_id = id; -} - -static int __init arch_init_ftrace_syscalls(void) -{ - int i; - struct syscall_metadata *meta; - unsigned long **psys_syscall_table = &sys_call_table; - - syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * - NR_syscalls, GFP_KERNEL); - if (!syscalls_metadata) { - WARN_ON(1); - return -ENOMEM; - } - - for (i = 0; i < NR_syscalls; i++) { - meta = find_syscall_meta(psys_syscall_table[i]); - syscalls_metadata[i] = meta; - } - return 0; + return (unsigned long)(&sys_call_table)[nr]; } -arch_initcall(arch_init_ftrace_syscalls); #endif diff --git a/include/trace/syscall.h b/include/trace/syscall.h index 5dc283ba5ae0..e972f0a40f8d 100644 --- a/include/trace/syscall.h +++ b/include/trace/syscall.h @@ -33,7 +33,7 @@ struct syscall_metadata { }; #ifdef CONFIG_FTRACE_SYSCALLS -extern struct syscall_metadata *syscall_nr_to_meta(int nr); +extern unsigned long arch_syscall_addr(int nr); extern int syscall_name_to_nr(char *name); void set_syscall_enter_id(int num, int id); void set_syscall_exit_id(int num, int id); diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 9fbce6c9d2e1..8bda4bff2286 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -14,6 +14,69 @@ static int sys_refcount_exit; static DECLARE_BITMAP(enabled_enter_syscalls, NR_syscalls); static DECLARE_BITMAP(enabled_exit_syscalls, NR_syscalls); +extern unsigned long __start_syscalls_metadata[]; +extern unsigned long __stop_syscalls_metadata[]; + +static struct syscall_metadata **syscalls_metadata; + +static struct syscall_metadata *find_syscall_meta(unsigned long syscall) +{ + struct syscall_metadata *start; + struct syscall_metadata *stop; + char str[KSYM_SYMBOL_LEN]; + + + start = (struct syscall_metadata *)__start_syscalls_metadata; + stop = (struct syscall_metadata *)__stop_syscalls_metadata; + kallsyms_lookup(syscall, NULL, NULL, NULL, str); + + for ( ; start < stop; start++) { + /* + * Only compare after the "sys" prefix. Archs that use + * syscall wrappers may have syscalls symbols aliases prefixed + * with "SyS" instead of "sys", leading to an unwanted + * mismatch. + */ + if (start->name && !strcmp(start->name + 3, str + 3)) + return start; + } + return NULL; +} + +static struct syscall_metadata *syscall_nr_to_meta(int nr) +{ + if (!syscalls_metadata || nr >= NR_syscalls || nr < 0) + return NULL; + + return syscalls_metadata[nr]; +} + +int syscall_name_to_nr(char *name) +{ + int i; + + if (!syscalls_metadata) + return -1; + + for (i = 0; i < NR_syscalls; i++) { + if (syscalls_metadata[i]) { + if (!strcmp(syscalls_metadata[i]->name, name)) + return i; + } + } + return -1; +} + +void set_syscall_enter_id(int num, int id) +{ + syscalls_metadata[num]->enter_id = id; +} + +void set_syscall_exit_id(int num, int id) +{ + syscalls_metadata[num]->exit_id = id; +} + enum print_line_t print_syscall_enter(struct trace_iterator *iter, int flags) { @@ -375,6 +438,29 @@ struct trace_event event_syscall_exit = { .trace = print_syscall_exit, }; +int __init init_ftrace_syscalls(void) +{ + struct syscall_metadata *meta; + unsigned long addr; + int i; + + syscalls_metadata = kzalloc(sizeof(*syscalls_metadata) * + NR_syscalls, GFP_KERNEL); + if (!syscalls_metadata) { + WARN_ON(1); + return -ENOMEM; + } + + for (i = 0; i < NR_syscalls; i++) { + addr = arch_syscall_addr(i); + meta = find_syscall_meta(addr); + syscalls_metadata[i] = meta; + } + + return 0; +} +core_initcall(init_ftrace_syscalls); + #ifdef CONFIG_EVENT_PROFILE static DECLARE_BITMAP(enabled_prof_enter_syscalls, NR_syscalls); -- cgit v1.2.3 From 55ca3cc1746335bb6ef1d3894ddb6d0c729b3518 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Wed, 28 Oct 2009 18:46:57 -0800 Subject: x86_64, ftrace: Make ftrace use kernel identity mapping to modify code On x86_64, kernel text mappings are mapped read-only with CONFIG_DEBUG_RODATA. So use the kernel identity mapping instead of the kernel text mapping to modify the kernel text. Signed-off-by: Suresh Siddha Acked-by: Steven Rostedt Tested-by: Steven Rostedt LKML-Reference: <20091029024821.080941108@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/ftrace.c | 17 +++++++++++++++++ arch/x86/mm/pageattr.c | 3 +-- 2 files changed, 18 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/ftrace.c') diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index 9dbb527e1652..944e9820b4b5 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -187,9 +187,26 @@ static void wait_for_nmi(void) nmi_wait_count++; } +static inline int +within(unsigned long addr, unsigned long start, unsigned long end) +{ + return addr >= start && addr < end; +} + static int do_ftrace_mod_code(unsigned long ip, void *new_code) { + /* + * On x86_64, kernel text mappings are mapped read-only with + * CONFIG_DEBUG_RODATA. So we use the kernel identity mapping instead + * of the kernel text mapping to modify the kernel text. + * + * For 32bit kernels, these mappings are same and we can use + * kernel identity mapping to modify code. + */ + if (within(ip, (unsigned long)_text, (unsigned long)_etext)) + ip = (unsigned long)__va(__pa(ip)); + mod_code_ip = (void *)ip; mod_code_newcode = new_code; diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 8d1e8d95ea45..09a140ca7be8 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -279,8 +279,7 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, __pa((unsigned long)__end_rodata) >> PAGE_SHIFT)) pgprot_val(forbidden) |= _PAGE_RW; -#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) && \ - !defined(CONFIG_DYNAMIC_FTRACE) +#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) /* * Once the kernel maps the text as RO (kernel_set_to_readonly is set), * kernel text mappings for the large page aligned text, rodata sections -- cgit v1.2.3