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From: Wei Liu <wei.liu2@citrix.com>
Date: Thu, 26 Jul 2018 15:58:54 +0100
Subject: xenpmd: make 32 bit gcc 8.1 non-debug build work
32 bit gcc 8.1 non-debug build yields:
xenpmd.c:354:23: error: '%02x' directive output may be truncated writing between 2 and 8 bytes into a region of size 3 [-Werror=format-truncation=]
snprintf(val, 3, "%02x",
^~~~
xenpmd.c:354:22: note: directive argument in the range [40, 2147483778]
snprintf(val, 3, "%02x",
^~~~~~
xenpmd.c:354:5: note: 'snprintf' output between 3 and 9 bytes into a destination of size 3
snprintf(val, 3, "%02x",
^~~~~~~~~~~~~~~~~~~~~~~~
(unsigned int)(9*4 +
~~~~~~~~~~~~~~~~~~~~
strlen(info->model_number) +
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
strlen(info->serial_number) +
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
strlen(info->battery_type) +
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
strlen(info->oem_info) + 4));
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All info->* used in calculation are 32 bytes long, and the parsing
code makes sure they are null-terminated, so the end result of the
expression won't exceed 255, which should be able to be fit into 3
bytes in hexadecimal format.
Add an assertion to make gcc happy.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
(cherry picked from commit e75c9dc85fdeeeda0b98d8cd8d784e0508c3ffb8)
---
tools/xenpmd/xenpmd.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/xenpmd/xenpmd.c b/tools/xenpmd/xenpmd.c
index 56412a9..1c801ca 100644
--- a/tools/xenpmd/xenpmd.c
+++ b/tools/xenpmd/xenpmd.c
@@ -40,6 +40,7 @@
#include <unistd.h>
#include <sys/stat.h>
#include <xenstore.h>
+#include <assert.h>
/* #define RUN_STANDALONE */
#define RUN_IN_SIMULATE_MODE
@@ -345,18 +346,17 @@ void write_ulong_lsb_first(char *temp_val, unsigned long val)
void write_battery_info_to_xenstore(struct battery_info *info)
{
char val[1024], string_info[256];
+ unsigned int len;
xs_mkdir(xs, XBT_NULL, "/pm");
memset(val, 0, 1024);
memset(string_info, 0, 256);
/* write 9 dwords (so 9*4) + length of 4 strings + 4 null terminators */
- snprintf(val, 3, "%02x",
- (unsigned int)(9*4 +
- strlen(info->model_number) +
- strlen(info->serial_number) +
- strlen(info->battery_type) +
- strlen(info->oem_info) + 4));
+ len = 9 * 4 + strlen(info->model_number) + strlen(info->serial_number) +
+ strlen(info->battery_type) + strlen(info->oem_info) + 4;
+ assert(len < 255);
+ snprintf(val, 3, "%02x", len);
write_ulong_lsb_first(val+2, info->present);
write_ulong_lsb_first(val+10, info->design_capacity);
write_ulong_lsb_first(val+18, info->last_full_capacity);
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