[RFC][PATCH 1/2] lib: printf: append support of '%*p[Mm][FR]'
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2012-06-29 15:58:56
Also in:
lkml
Subsystem:
library code, the rest, vsprintf · Maintainers:
Andrew Morton, Linus Torvalds, Petr Mladek, Steven Rostedt
There are many places in the kernel where the drivers print small buffers as a hex string. This patch adds a support of the variable width buffer to print it as a hex string with a delimiter. The idea came from Pavel Roskin here: http://www.digipedia.pl/usenet/thread/18835/17449/ Sample output of pr_info("buf[%d:%d] %*pM\n", from, len, len, &buf[from]); could be like this: [ 0.726130] buf[51:8] e8:16:b6:ef:e3:74:45:6e [ 0.750736] buf[59:15] 31:81:b8:3f:35:49:06:ae:df:32:06:05:4a:af:55 [ 0.757602] buf[17:5] ac:16:d5:2c:ef Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- lib/vsprintf.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index a0b5f15..1645d7e 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c@@ -655,11 +655,12 @@ char *resource_string(char *buf, char *end, struct resource *res, } static noinline_for_stack -char *mac_address_string(char *buf, char *end, u8 *addr, - struct printf_spec spec, const char *fmt) +char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, + const char *fmt) { - char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; - char *p = mac_addr; + char hex_str[64*3]; /* support up to 64 bytes to print */ + int len = 6; /* default length is 6 bytes */ + char *p = hex_str; int i; char separator; bool reversed = false;
@@ -678,18 +679,21 @@ char *mac_address_string(char *buf, char *end, u8 *addr, break; } - for (i = 0; i < 6; i++) { + if (spec.field_width > 0) + len = min_t(int, spec.field_width, 64); + + for (i = 0; i < len; i++) { if (reversed) - p = hex_byte_pack(p, addr[5 - i]); + p = hex_byte_pack(p, addr[len - 1 - i]); else p = hex_byte_pack(p, addr[i]); - if (fmt[0] == 'M' && i != 5) + if (fmt[0] == 'M' && i != len - 1) *p++ = separator; } *p = '\0'; - return string(buf, end, mac_addr, spec); + return string(buf, end, hex_str, spec); } static noinline_for_stack
@@ -1011,7 +1015,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, case 'm': /* Contiguous: 000102030405 */ /* [mM]F (FDDI) */ /* [mM]R (Reverse order; Bluetooth) */ - return mac_address_string(buf, end, ptr, spec, fmt); + return hex_string(buf, end, ptr, spec, fmt); case 'I': /* Formatted IP supported * 4: 1.2.3.4 * 6: 0001:0203:...:0708
--
1.7.10