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 <zhaolei@cn.fujitsu.com>
Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: torvalds@linux-foundation.org
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49CC9739.30107@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files 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;