diff options
author | Stephen Boyd <sboyd@codeaurora.org> | 2012-05-30 02:07:33 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-05-30 03:22:32 +0400 |
commit | 4796dd200db943e36f876e7029552212e5bbdf33 (patch) | |
tree | a594c2b1ce1f4dbc96b25a516e49655917a9fa30 | |
parent | 05a6c8a9226599f921bd0b6e439dbc04df96a6fc (diff) | |
download | linux-4796dd200db943e36f876e7029552212e5bbdf33.tar.xz |
vsprintf: fix %ps on non symbols when using kallsyms
Using %ps in a printk format will sometimes fail silently and print the
empty string if the address passed in does not match a symbol that
kallsyms knows about. But using %pS will fall back to printing the full
address if kallsyms can't find the symbol. Make %ps act the same as %pS
by falling back to printing the address.
While we're here also make %ps print the module that a symbol comes from
so that it matches what %pS already does. Take this simple function for
example (in a module):
static void test_printk(void)
{
int test;
pr_info("with pS: %pS\n", &test);
pr_info("with ps: %ps\n", &test);
}
Before this patch:
with pS: 0xdff7df44
with ps:
After this patch:
with pS: 0xdff7df44
with ps: 0xdff7df44
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/kallsyms.h | 7 | ||||
-rw-r--r-- | kernel/kallsyms.c | 32 | ||||
-rw-r--r-- | lib/vsprintf.c | 2 |
3 files changed, 32 insertions, 9 deletions
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 387571959dd9..6883e197acb9 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -36,6 +36,7 @@ const char *kallsyms_lookup(unsigned long addr, /* Look up a kernel symbol and return it in a text buffer. */ extern int sprint_symbol(char *buffer, unsigned long address); +extern int sprint_symbol_no_offset(char *buffer, unsigned long address); extern int sprint_backtrace(char *buffer, unsigned long address); /* Look up a kernel symbol and print it to the kernel messages. */ @@ -80,6 +81,12 @@ static inline int sprint_symbol(char *buffer, unsigned long addr) return 0; } +static inline int sprint_symbol_no_offset(char *buffer, unsigned long addr) +{ + *buffer = '\0'; + return 0; +} + static inline int sprint_backtrace(char *buffer, unsigned long addr) { *buffer = '\0'; diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 079f1d39a8b8..2169feeba529 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -343,7 +343,7 @@ int lookup_symbol_attrs(unsigned long addr, unsigned long *size, /* Look up a kernel symbol and return it in a text buffer. */ static int __sprint_symbol(char *buffer, unsigned long address, - int symbol_offset) + int symbol_offset, int add_offset) { char *modname; const char *name; @@ -358,13 +358,13 @@ static int __sprint_symbol(char *buffer, unsigned long address, if (name != buffer) strcpy(buffer, name); len = strlen(buffer); - buffer += len; offset -= symbol_offset; + if (add_offset) + len += sprintf(buffer + len, "+%#lx/%#lx", offset, size); + if (modname) - len += sprintf(buffer, "+%#lx/%#lx [%s]", offset, size, modname); - else - len += sprintf(buffer, "+%#lx/%#lx", offset, size); + len += sprintf(buffer + len, " [%s]", modname); return len; } @@ -382,12 +382,28 @@ static int __sprint_symbol(char *buffer, unsigned long address, */ int sprint_symbol(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, 0); + return __sprint_symbol(buffer, address, 0, 1); } - EXPORT_SYMBOL_GPL(sprint_symbol); /** + * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer + * @buffer: buffer to be stored + * @address: address to lookup + * + * This function looks up a kernel symbol with @address and stores its name + * and module name to @buffer if possible. If no symbol was found, just saves + * its @address as is. + * + * This function returns the number of bytes stored in @buffer. + */ +int sprint_symbol_no_offset(char *buffer, unsigned long address) +{ + return __sprint_symbol(buffer, address, 0, 0); +} +EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); + +/** * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer * @buffer: buffer to be stored * @address: address to lookup @@ -403,7 +419,7 @@ EXPORT_SYMBOL_GPL(sprint_symbol); */ int sprint_backtrace(char *buffer, unsigned long address) { - return __sprint_symbol(buffer, address, -1); + return __sprint_symbol(buffer, address, -1, 1); } /* Look up a kernel symbol and print it to the kernel messages. */ diff --git a/lib/vsprintf.c b/lib/vsprintf.c index abbabec9720a..f5dfe0ca34f6 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -436,7 +436,7 @@ char *symbol_string(char *buf, char *end, void *ptr, else if (ext != 'f' && ext != 's') sprint_symbol(sym, value); else - kallsyms_lookup(value, NULL, NULL, NULL, sym); + sprint_symbol_no_offset(sym, value); return string(buf, end, sym, spec); #else |