diff options
| author | Joe Perches <joe@perches.com> | 2010-06-27 01:02:33 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-07-04 10:40:17 -0700 |
| commit | 7db6f5fb65a82af03229eef104dc9899c5eecf33 (patch) | |
| tree | fb7a83297d8bf2680df9616ebf58bec89229ff3b | |
| parent | e490c1defec4236a6a131fe2d13bf7ba787c02f8 (diff) | |
vsprintf: Recursive vsnprintf: Add "%pV", struct va_format
Add the ability to print a format and va_list from a structure pointer
Allows __dev_printk to be implemented as a single printk while
minimizing string space duplication.
%pV should not be used without some mechanism to verify the
format and argument use ala __attribute__(format (printf(...))).
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/kernel.h | 5 | ||||
| -rw-r--r-- | lib/vsprintf.c | 9 |
2 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 8317ec4b9f3..01dfc05ef4a 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -171,6 +171,11 @@ static inline void might_fault(void) } #endif +struct va_format { + const char *fmt; + va_list *va; +}; + extern struct atomic_notifier_head panic_notifier_list; extern long (*panic_blink)(long time); NORET_TYPE void panic(const char * fmt, ...) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index b8a2f549ab0..4ee19d0d391 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -980,6 +980,11 @@ char *uuid_string(char *buf, char *end, const u8 *addr, * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] * little endian output byte order is: * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] + * - 'V' For a struct va_format which contains a format string * and va_list *, + * call vsnprintf(->format, *->va_list). + * Implements a "recursive vsnprintf". + * Do not use this feature without some mechanism to verify the + * correctness of the format string and va_list arguments. * * Note: The difference between 'S' and 'F' is that on ia64 and ppc64 * function pointers are really function descriptors, which contain a @@ -1025,6 +1030,10 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, break; case 'U': return uuid_string(buf, end, ptr, spec, fmt); + case 'V': + return buf + vsnprintf(buf, end - buf, + ((struct va_format *)ptr)->fmt, + *(((struct va_format *)ptr)->va)); } spec.flags |= SMALL; if (spec.field_width == -1) { |