[PATCH 0/2] tools: fix gcc 8.1 build

[PATCH 0/2] tools: fix gcc 8.1 build

[Wei Liu]

Wei Liu (2):
  tools: update ipxe changeset
  xenpmd: make 32 bit gcc 8.1 non-debug build work

 tools/firmware/etherboot/Makefile |  2 +-
 tools/xenpmd/xenpmd.c             | 12 ++++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

-- 
2.11.0


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[PATCH 1/2] tools: update ipxe changeset

[Wei Liu]

This placates gcc 8.1. The commit comes from ipxe master branch as of
July 25, 2018.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/firmware/etherboot/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/firmware/etherboot/Makefile b/tools/firmware/etherboot/Makefile
index 4de6d24a13..3868f876ea 100644
--- a/tools/firmware/etherboot/Makefile
+++ b/tools/firmware/etherboot/Makefile
@@ -10,7 +10,7 @@ else
 IPXE_GIT_URL ?= git://git.ipxe.org/ipxe.git
 endif
 
-IPXE_GIT_TAG := 356f6c1b64d7a97746d1816cef8ca22bdd8d0b5d
+IPXE_GIT_TAG := d2063b7693e0e35db97b2264aa987eb6341ae779
 
 IPXE_TARBALL_URL ?= $(XEN_EXTFILES_URL)/ipxe-git-$(IPXE_GIT_TAG).tar.gz
 
-- 
2.11.0


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[PATCH 2/2] xenpmd: make 32 bit gcc 8.1 non-debug build work

[Wei Liu]

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>
---
 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 56412a9a81..1c801caa71 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);
-- 
2.11.0


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Re: [PATCH 2/2] xenpmd: make 32 bit gcc 8.1 non-debug build work

[Ian Jackson]

Wei Liu writes ("[PATCH 2/2] xenpmd: make 32 bit gcc 8.1 non-debug build work"):
> 32 bit gcc 8.1 non-debug build yields:
...
>      /* 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));

This is pretty unpleasant!

> +    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);

This is slightly less unpleasant, I guess...

Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

Thanks,
Ian.

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Re: [PATCH 1/2] tools: update ipxe changeset

[Ian Jackson]

Wei Liu writes ("[PATCH 1/2] tools: update ipxe changeset"):
> This placates gcc 8.1. The commit comes from ipxe master branch as of
> July 25, 2018.

Fine, whatever.  FTR, I don't think it is useful to ask for an ack of
this kind of patch, assuming the commit is indeed from ipxe master.
(And if some kind of review were needed, we would need much more
information in the commit message about what changed.)

Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

Thanks,
Ian.

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