From a4e94ef0dd391eae05bdeacd12b8da3510957a97 Mon Sep 17 00:00:00 2001 From: Zhaolei Date: Fri, 27 Mar 2009 17:07:05 +0800 Subject: [PATCH 1/2] printk: add support of hh length modifier for printk Impact: new feature, extend vsprintf format strings hh is used as length modifier for signed char or unsigned char. It is supported by glibc, we add kernel support now. Signed-off-by: Zhao Lei Acked-by: Lai Jiangshan Acked-by: Frederic Weisbecker Cc: torvalds@linux-foundation.org Cc: Steven Rostedt LKML-Reference: <49CC9739.30107@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- lib/vsprintf.c | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 7536acea135b..b56f6d039d21 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -408,6 +408,8 @@ enum format_type { FORMAT_TYPE_LONG_LONG, FORMAT_TYPE_ULONG, FORMAT_TYPE_LONG, + FORMAT_TYPE_UBYTE, + FORMAT_TYPE_BYTE, FORMAT_TYPE_USHORT, FORMAT_TYPE_SHORT, FORMAT_TYPE_UINT, @@ -853,11 +855,15 @@ qualifier: spec->qualifier = -1; if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' || *fmt == 'Z' || *fmt == 'z' || *fmt == 't') { - spec->qualifier = *fmt; - ++fmt; - if (spec->qualifier == 'l' && *fmt == 'l') { - spec->qualifier = 'L'; - ++fmt; + spec->qualifier = *fmt++; + if (unlikely(spec->qualifier == *fmt)) { + if (spec->qualifier == 'l') { + spec->qualifier = 'L'; + ++fmt; + } else if (spec->qualifier == 'h') { + spec->qualifier = 'H'; + ++fmt; + } } } @@ -919,6 +925,11 @@ qualifier: spec->type = FORMAT_TYPE_SIZE_T; } else if (spec->qualifier == 't') { spec->type = FORMAT_TYPE_PTRDIFF; + } else if (spec->qualifier == 'H') { + if (spec->flags & SIGN) + spec->type = FORMAT_TYPE_BYTE; + else + spec->type = FORMAT_TYPE_UBYTE; } else if (spec->qualifier == 'h') { if (spec->flags & SIGN) spec->type = FORMAT_TYPE_SHORT; @@ -1087,6 +1098,12 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) case FORMAT_TYPE_PTRDIFF: num = va_arg(args, ptrdiff_t); break; + case FORMAT_TYPE_UBYTE: + num = (unsigned char) va_arg(args, int); + break; + case FORMAT_TYPE_BYTE: + num = (signed char) va_arg(args, int); + break; case FORMAT_TYPE_USHORT: num = (unsigned short) va_arg(args, int); break; @@ -1363,6 +1380,10 @@ do { \ case FORMAT_TYPE_PTRDIFF: save_arg(ptrdiff_t); break; + case FORMAT_TYPE_UBYTE: + case FORMAT_TYPE_BYTE: + save_arg(char); + break; case FORMAT_TYPE_USHORT: case FORMAT_TYPE_SHORT: save_arg(short); @@ -1538,6 +1559,12 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) case FORMAT_TYPE_PTRDIFF: num = get_arg(ptrdiff_t); break; + case FORMAT_TYPE_UBYTE: + num = get_arg(unsigned char); + break; + case FORMAT_TYPE_BYTE: + num = get_arg(signed char); + break; case FORMAT_TYPE_USHORT: num = get_arg(unsigned short); break; From 0c8b946e3ebb3846103486420ea7430a4b5e5b1b Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Wed, 15 Apr 2009 17:48:18 +0200 Subject: [PATCH 2/2] vsprintf: introduce %pf format specifier A printf format specifier which would allow us to print a pure function name has been suggested by Andrew Morton a couple of months 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 %pf does in this patch. The lowecase f has been chosen for its intuitive meaning of a 'weak kind of %pF'. The support for this new format would be welcome by the tracing code where the need to print pure function names is often needed. This is also true for other parts of the kernel: $ 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 explanation 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 Acked-by: Mike Frysinger Cc: Linus Torvalds Cc: Zhaolei Cc: Tom Zanussi Cc: Li Zefan Cc: Andrew Morton Cc: Steven Rostedt LKML-Reference: <20090415154817.GC5989@nowhere> Signed-off-by: Ingo Molnar --- lib/vsprintf.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index b56f6d039d21..756ccafa9cec 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 *