[libc] Small recvfrom fixes (yaml, unpoison)

[michaelrj-google]

Forgot to update the newhdrgen yaml (old headergen is fine) and forgot
to unpoison addrlen. This patch fixes those.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Michael Jones (michaelrj-google)

Changes

Forgot to update the newhdrgen yaml (old headergen is fine) and forgot
to unpoison addrlen. This patch fixes those.

---

Full diff: https://github.com/llvm/llvm-project/pull/111020.diff

2 Files Affected:

• (modified) libc/newhdrgen/yaml/sys/socket.yaml (+1-1)
• (modified) libc/src/sys/socket/linux/recvfrom.cpp (+1)

diff --git a/libc/newhdrgen/yaml/sys/socket.yaml b/libc/newhdrgen/yaml/sys/socket.yaml
index accb4b14099e82..45602d4b3bff03 100644
--- a/libc/newhdrgen/yaml/sys/socket.yaml
+++ b/libc/newhdrgen/yaml/sys/socket.yaml
@@ -62,7 +62,7 @@ functions:
       - type: size_t
       - type: int
       - type: const struct sockaddr *
-      - type: socklen_t
+      - type: socklen_t *
   - name: recvmsg
     standards:
       - POSIX
diff --git a/libc/src/sys/socket/linux/recvfrom.cpp b/libc/src/sys/socket/linux/recvfrom.cpp
index fdcaceee8ad293..791005529acdf2 100644
--- a/libc/src/sys/socket/linux/recvfrom.cpp
+++ b/libc/src/sys/socket/linux/recvfrom.cpp
@@ -45,6 +45,7 @@ LLVM_LIBC_FUNCTION(ssize_t, recvfrom,
   }
 
   MSAN_UNPOISON(buf, ret);
+  MSAN_UNPOISON(addrlen, sizeof(socklen_t));
 
   return ret;
 }

[nickdesaulniers]

man 2 recvfrom doesn't mention const for any of the parameters. restrict and _Nullable would be nice to add (IIRC, restrict isn't supported in C++ except via compiler extension.

[michaelrj-google]

Fixed const, added restrict. Planning to land later today if there are no further comments.