POSIX does not allow "tv" to be NULL.
On glibc and gnulib calling gettimeofday(NULL, NULL) can segfault.
For glibc see __gettimeofday() and __gettimeofday64() in
sysdeps/unix/sysv/linux/gettimeofday.c.
Note that by default glibc may use the gettimeofday() syscall or vdso
function which both support "tv" to be NULL.
The segfault can be triggered by compiling a i386 binary on a x86_64
system.
Signed-off-by: Thomas Weißschuh <thomas@xxxxxxxx>
---
man2/gettimeofday.2 | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/man2/gettimeofday.2 b/man2/gettimeofday.2
index 9d134fa49de7..cdbec5ede23c 100644
--- a/man2/gettimeofday.2
+++ b/man2/gettimeofday.2
@@ -85,16 +85,14 @@ struct timezone {
.EE
.in
.PP
-If either
-.I tv
-or
+If
.I tz
-is NULL, the corresponding structure is not set or returned.
+is NULL, the structure is not set or returned.
.\" FIXME . The compilation warning looks to be going away in glibc 2.17
.\" see glibc commit 4b7634a5e03b0da6f8875de9d3f74c1cf6f2a6e8
-(However, compilation warnings will result if
+If
.I tv
-is NULL.)
+is NULL, the behavior is unspecified.
.\" The following is covered under EPERM below:
.\" .PP
.\" Only the superuser may use
---
base-commit: f0067f73941ea0e512b9018a123472508a0858db
change-id: 20230530-gettimeofday-null-7ee404b7825f
Best regards,
--
Thomas Weißschuh <thomas@xxxxxxxx>
