[PULL 2/8] target/s390x/arch_dump: Fix warning for the name field in the PT_NOTE section

Cornelia Huck posted 8 patches 4 years, 11 months ago
Maintainers: Christian Borntraeger <borntraeger@de.ibm.com>, Cornelia Huck <cohuck@redhat.com>, Matthew Rosato <mjrosato@linux.ibm.com>, Halil Pasic <pasic@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, David Hildenbrand <david@redhat.com>, Alex Williamson <alex.williamson@redhat.com>, Eric Farman <farman@linux.ibm.com>, "Michael S. Tsirkin" <mst@redhat.com>, Richard Henderson <richard.henderson@linaro.org>
There is a newer version of this series
[PULL 2/8] target/s390x/arch_dump: Fix warning for the name field in the PT_NOTE section
Posted by Cornelia Huck 4 years, 11 months ago
From: Thomas Huth <thuth@redhat.com>

There is a compiler warning with GCC 9.3 when compiling with
the -fsanitize=thread compiler flag:

 In function 'strncpy',
    inlined from 's390x_write_elf64_notes' at ../target/s390x/arch_dump.c:219:9:
 /usr/include/x86_64-linux-gnu/bits/string_fortified.h:106:10: error:
  '__builtin_strncpy' specified bound 8 equals destination size
  [-Werror=stringop-truncation]

Since the name should always be NUL-terminated, let's use g_strlcpy() to
silence this warning. And while we're at it, also add an assert() to make
sure that the provided names always fit the size field (which is fine for
the current callers, the function is called once with "CORE" and once with
"LINUX" as a name).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20210205093921.848260-1-thuth@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 target/s390x/arch_dump.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/s390x/arch_dump.c b/target/s390x/arch_dump.c
index 50fa0ae4b679..cc1330876bef 100644
--- a/target/s390x/arch_dump.c
+++ b/target/s390x/arch_dump.c
@@ -212,11 +212,13 @@ static int s390x_write_elf64_notes(const char *note_name,
     int note_size;
     int ret = -1;
 
+    assert(strlen(note_name) < sizeof(note.name));
+
     for (nf = funcs; nf->note_contents_func; nf++) {
         memset(&note, 0, sizeof(note));
         note.hdr.n_namesz = cpu_to_be32(strlen(note_name) + 1);
         note.hdr.n_descsz = cpu_to_be32(nf->contents_size);
-        strncpy(note.name, note_name, sizeof(note.name));
+        g_strlcpy(note.name, note_name, sizeof(note.name));
         (*nf->note_contents_func)(&note, cpu, id);
 
         note_size = sizeof(note) - sizeof(note.contents) + nf->contents_size;
-- 
2.26.2