From ef12496022d5917cfe0b04cf8fd685fc6bc08400 Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Date: Mon, 17 Dec 2012 15:59:58 -0800
Subject: [PATCH] lib/vsprintf.c: fix handling of %zd when using ssize_t

Documentation/printk-formats.txt says to use %zd for a ssize_t argument
and some drivers do.  Unfortunately this prints a positive number for
negative values eg:

  tpm_tis 70030000.tpm_tis: tpm_transmit: tpm_send: error 4294967234

Add a case to va_args a ssize_t type if the interpretation should be
signed.

Tested on PPC32.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 lib/vsprintf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 39c99fea7c03..41da0741a663 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1485,7 +1485,10 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
 				num = va_arg(args, long);
 				break;
 			case FORMAT_TYPE_SIZE_T:
-				num = va_arg(args, size_t);
+				if (spec.flags & SIGN)
+					num = va_arg(args, ssize_t);
+				else
+					num = va_arg(args, size_t);
 				break;
 			case FORMAT_TYPE_PTRDIFF:
 				num = va_arg(args, ptrdiff_t);
-- 
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