| Message ID | 20230630143050.3334599-1-josimmon@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] getaddrinfo: Get rid of alloca | expand |
Ping. On Fri, Jun 30, 2023 at 10:30:50AM -0400, Joe Simmons-Talbott wrote: > Use a scratch_buffer rather than alloca to avoid potential stack > overflow. > --- > Changes to v1: > * Don't use alloc_size but rather rely on * scratch_buffer_set_array_size's > overflow checks. > > sysdeps/posix/getaddrinfo.c | 24 +++++++++--------------- > 1 file changed, 9 insertions(+), 15 deletions(-) > > diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c > index 0356b622be..be3b3f6e45 100644 > --- a/sysdeps/posix/getaddrinfo.c > +++ b/sysdeps/posix/getaddrinfo.c > @@ -2404,22 +2404,17 @@ getaddrinfo (const char *name, const char *service, > struct addrinfo *q; > struct addrinfo *last = NULL; > char *canonname = NULL; > - bool malloc_results; > - size_t alloc_size = nresults * (sizeof (*results) + sizeof (size_t)); > + struct scratch_buffer buf; > + scratch_buffer_init (&buf); > > - malloc_results > - = !__libc_use_alloca (alloc_size); > - if (malloc_results) > + if (!scratch_buffer_set_array_size (&buf, nresults, > + sizeof (*results) + sizeof (size_t))) > { > - results = malloc (alloc_size); > - if (results == NULL) > - { > - __free_in6ai (in6ai); > - return EAI_MEMORY; > - } > + __free_in6ai (in6ai); > + return EAI_MEMORY; > } > - else > - results = alloca (alloc_size); > + results = buf.data; > + > order = (size_t *) (results + nresults); > > /* Now we definitely need the interface information. */ > @@ -2590,8 +2585,7 @@ getaddrinfo (const char *name, const char *service, > /* Fill in the canonical name into the new first entry. */ > p->ai_canonname = canonname; > > - if (malloc_results) > - free (results); > + scratch_buffer_free (&buf); > } > > __free_in6ai (in6ai); > -- > 2.39.2 >
On Jun 30 2023, Joe Simmons-Talbott via Libc-alpha wrote: > Use a scratch_buffer rather than alloca to avoid potential stack > overflow. Ok.
diff --git a/sysdeps/posix/getaddrinfo.c b/sysdeps/posix/getaddrinfo.c index 0356b622be..be3b3f6e45 100644 --- a/sysdeps/posix/getaddrinfo.c +++ b/sysdeps/posix/getaddrinfo.c @@ -2404,22 +2404,17 @@ getaddrinfo (const char *name, const char *service, struct addrinfo *q; struct addrinfo *last = NULL; char *canonname = NULL; - bool malloc_results; - size_t alloc_size = nresults * (sizeof (*results) + sizeof (size_t)); + struct scratch_buffer buf; + scratch_buffer_init (&buf); - malloc_results - = !__libc_use_alloca (alloc_size); - if (malloc_results) + if (!scratch_buffer_set_array_size (&buf, nresults, + sizeof (*results) + sizeof (size_t))) { - results = malloc (alloc_size); - if (results == NULL) - { - __free_in6ai (in6ai); - return EAI_MEMORY; - } + __free_in6ai (in6ai); + return EAI_MEMORY; } - else - results = alloca (alloc_size); + results = buf.data; + order = (size_t *) (results + nresults); /* Now we definitely need the interface information. */ @@ -2590,8 +2585,7 @@ getaddrinfo (const char *name, const char *service, /* Fill in the canonical name into the new first entry. */ p->ai_canonname = canonname; - if (malloc_results) - free (results); + scratch_buffer_free (&buf); } __free_in6ai (in6ai);
Use a scratch_buffer rather than alloca to avoid potential stack overflow. --- Changes to v1: * Don't use alloc_size but rather rely on * scratch_buffer_set_array_size's overflow checks. sysdeps/posix/getaddrinfo.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-)