Messages in this thread Patch in this message |  | | | Date | Wed, 15 Apr 2009 17:48:18 +0200 | | From | Frederic Weisbecker <> | | Subject | [PATCH v2] vsprintf: introduce %pf |
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On Tue, Apr 14, 2009 at 10:38:36PM -0400, Steven Rostedt wrote: > > On Tue, 14 Apr 2009, Mike Frysinger wrote: > > > On Tue, Apr 14, 2009 at 20:00, Frederic Weisbecker wrote: > > > - * - 'F' For symbolic function descriptor pointers > > > + * - 'F' For symbolic function descriptor pointers with asm offset > > > + * - 'f' For simple function symbol > > > > "asm" is weird here as it isnt an assembly offset (not that i have any > > idea what an "assembly offset" even means). just say "offset". > > Or perhaps better: function offset, as it ususally means the offset into > the function. > > -- Steve >
Ok, I've tried to keep a balance between all your comments. Tell me what your think about this v2:
-- From 302d8752d1734242ab1eb7d9e5df637bcba3f4a9 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker <fweisbec@gmail.com> Date: Wed, 15 Apr 2009 17:41:56 +0200 Subject: [PATCH v2] vsprintf: introduce %pf
If I remember well, a format which could let us to print a pure function name has been suggested by Andrew Morton some monthes ago.
The current %pF is very convenient to print a function symbol, but often we only want to print the name of the function, without its asm offset.
That's what does %pf in this patch. The lowecase f has been chosen for its intuitive sense of a weak kind of %pF
The support for this new format would be welcome for the tracing tree where the need to print pure function names is often needed and also on other parts:
$ git-grep -E "kallsyms_lookup\(.+?\)" arch/blackfin/kernel/traps.c: symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf); arch/powerpc/xmon/xmon.c: name = kallsyms_lookup(pc, &size, &offset, NULL, tmpstr); arch/sh/kernel/cpu/sh5/unwind.c: sym = kallsyms_lookup(pc, NULL, &offset, NULL, namebuf); arch/x86/kernel/ftrace.c: kallsyms_lookup((unsigned long) syscall, NULL, NULL, NULL, str); kernel/kprobes.c: sym = kallsyms_lookup((unsigned long)p->addr, NULL, kernel/lockdep.c: return kallsyms_lookup((unsigned long)key, NULL, NULL, NULL, str); kernel/trace/ftrace.c: kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); kernel/trace/ftrace.c: kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); kernel/trace/ftrace.c: kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); kernel/trace/ftrace.c: kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); kernel/trace/ftrace.c: kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); kernel/trace/ftrace.c: kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); kernel/trace/ftrace.c: kallsyms_lookup(*ptr, NULL, NULL, NULL, str); kernel/trace/trace_functions.c: kallsyms_lookup(ip, NULL, NULL, NULL, str); kernel/trace/trace_output.c: kallsyms_lookup(address, NULL, NULL, NULL, str);
Changes in v2:
- Add the explanations of the %pf role for vsnprintf() and bstr_printf() - Change the comments by dropping the "asm offset" notion and only define the %pf against the actual function offset notion.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> --- lib/vsprintf.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index b56f6d0..756ccaf 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -575,12 +575,15 @@ static char *string(char *buf, char *end, char *s, struct printf_spec spec) } static char *symbol_string(char *buf, char *end, void *ptr, - struct printf_spec spec) + struct printf_spec spec, char ext) { unsigned long value = (unsigned long) ptr; #ifdef CONFIG_KALLSYMS char sym[KSYM_SYMBOL_LEN]; - sprint_symbol(sym, value); + if (ext != 'f') + sprint_symbol(sym, value); + else + kallsyms_lookup(value, NULL, NULL, NULL, sym); return string(buf, end, sym, spec); #else spec.field_width = 2*sizeof(void *); @@ -692,7 +695,8 @@ static char *ip4_addr_string(char *buf, char *end, u8 *addr, * * Right now we handle: * - * - 'F' For symbolic function descriptor pointers + * - 'F' For symbolic function descriptor pointers with offset + * - 'f' For simple symbolic function names without offset * - 'S' For symbolic direct pointers * - 'R' For a struct resource pointer, it prints the range of * addresses (not the name nor the flags) @@ -715,10 +719,11 @@ static char *pointer(const char *fmt, char *buf, char *end, void *ptr, switch (*fmt) { case 'F': + case 'f': ptr = dereference_function_descriptor(ptr); /* Fallthrough */ case 'S': - return symbol_string(buf, end, ptr, spec); + return symbol_string(buf, end, ptr, spec, *fmt); case 'R': return resource_string(buf, end, ptr, spec); case 'm': @@ -954,7 +959,8 @@ qualifier: * * This function follows C99 vsnprintf, but has some extensions: * %pS output the name of a text symbol - * %pF output the name of a function pointer + * %pF output the name of a function pointer with its offset + * %pf output the name of a function pointer without its offset * %pR output the address range in a struct resource * * The return value is the number of characters which would @@ -1412,7 +1418,8 @@ EXPORT_SYMBOL_GPL(vbin_printf); * * The format follows C99 vsnprintf, but has some extensions: * %pS output the name of a text symbol - * %pF output the name of a function pointer + * %pF output the name of a function pointer with its offset + * %pf output the name of a function pointer without its offset * %pR output the address range in a struct resource * %n is ignored * -- 1.6.1
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