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Commit 725fe002 authored by Grant Likely's avatar Grant Likely Committed by Linus Torvalds
Browse files

vsprintf: correctly handle width when '#' flag used in %#p format 



The '%p' output of the kernel's vsprintf() uses spec.field_width to
determine how many digits to output based on 2 * sizeof(void*) so that all
digits of a pointer are shown.  ie.  a pointer will be output as
"001A2B3C" instead of "1A2B3C".  However, if the '#' flag is used in the
format (%#p), then the code doesn't take into account the width of the
'0x' prefix and will end up outputing "0x1A2B3C" instead of "0x001A2B3C".

This patch reworks the "pointer()" format hook to include 2 characters for
the '0x' prefix if the '#' flag is included.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d84970bb

lib/vsprintf.c

+5 −3
Original line number Diff line number Diff line
@@ -870,13 +870,15 @@ static noinline_for_stack 
char *pointer(const char *fmt, char *buf, char *end, void *ptr,

	      struct printf_spec spec)

{

	int default_width = 2 * sizeof(void *) + (spec.flags & SPECIAL ? 2 : 0);



	if (!ptr && *fmt != 'K') {

		/*

		 * Print (null) with the same width as a pointer so it makes

		 * tabular output look nice.

		 */

		if (spec.field_width == -1)

			spec.field_width = 2 * sizeof(void *);

			spec.field_width = default_width;

		return string(buf, end, "(null)", spec);

	}
@@ -931,7 +933,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, 
		 */

		if (in_irq() || in_serving_softirq() || in_nmi()) {

			if (spec.field_width == -1)

				spec.field_width = 2 * sizeof(void *);

				spec.field_width = default_width;

			return string(buf, end, "pK-error", spec);

		}

		if (!((kptr_restrict == 0) ||
@@ -948,7 +950,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, 
	}

	spec.flags |= SMALL;

	if (spec.field_width == -1) {

		spec.field_width = 2 * sizeof(void *);

		spec.field_width = default_width;

		spec.flags |= ZEROPAD;

	}

	spec.base = 16;