2012-11-21 06:56:27

by Jason Gunthorpe

[permalink] [raw]
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 <[email protected]>
---
lib/vsprintf.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 39c99fe..41da074 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);
--
1.7.4.1