| Message ID | 20230620184154.3804141-1-josimmon@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | libc_fatal: Add comment regarding alloca usage. | expand |
On Tue, Jun 20, 2023 at 02:41:54PM -0400, Joe Simmons-Talbott wrote: > Since __libc_message is only used in a few places and always with a > const char * format string and a small fixed-sized struct the usage of > alloca here is safe. Add a comment explaining this for both alloca > usages. Ping. Thanks, Joe > --- > sysdeps/posix/libc_fatal.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/sysdeps/posix/libc_fatal.c b/sysdeps/posix/libc_fatal.c > index 70edcc10c1..caa01bcbf6 100644 > --- a/sysdeps/posix/libc_fatal.c > +++ b/sysdeps/posix/libc_fatal.c > @@ -100,6 +100,9 @@ __libc_message (const char *fmt, ...) > cp = next; > } > > + /* alloca is safe here since the current usage of __libc_message uses > + relatively short const char * format strings and a small fixed size > + struct. */ > struct str_list *newp = alloca (sizeof (struct str_list)); > newp->str = str; > newp->len = len; > @@ -110,6 +113,9 @@ __libc_message (const char *fmt, ...) > > if (nlist > 0) > { > + /* alloca is safe here since the current usage of __libc_message uses > + relatively short const char * format strings and a small fixed size > + struct. */ > struct iovec *iov = alloca (nlist * sizeof (struct iovec)); > ssize_t total = 0; > > -- > 2.39.2 >
diff --git a/sysdeps/posix/libc_fatal.c b/sysdeps/posix/libc_fatal.c index 70edcc10c1..caa01bcbf6 100644 --- a/sysdeps/posix/libc_fatal.c +++ b/sysdeps/posix/libc_fatal.c @@ -100,6 +100,9 @@ __libc_message (const char *fmt, ...) cp = next; } + /* alloca is safe here since the current usage of __libc_message uses + relatively short const char * format strings and a small fixed size + struct. */ struct str_list *newp = alloca (sizeof (struct str_list)); newp->str = str; newp->len = len; @@ -110,6 +113,9 @@ __libc_message (const char *fmt, ...) if (nlist > 0) { + /* alloca is safe here since the current usage of __libc_message uses + relatively short const char * format strings and a small fixed size + struct. */ struct iovec *iov = alloca (nlist * sizeof (struct iovec)); ssize_t total = 0;