target/s390x/arch_dump: Fix warning for the name field in the PT_NOTE section

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>

diff --git a/target/s390x/arch_dump.c b/target/s390x/arch_dump.c
index 50fa0ae4b679d0715a0f9afa836b9cebe2278521..cc1330876befe1f5a8d0f6a14d1ae64ffa1c2f74 100644 (file)
--- 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;