From 566782ab138cbc9e1442b297901dcd0eeb81c899 Mon Sep 17 00:00:00 2001
From: Sam Clegg <sbc@chromium.org>
Date: Mon, 1 Jun 2026 16:13:27 -0700
Subject: [PATCH] Remove __syscall_pause

---
 system/include/emscripten/syscalls.h                | 1 -
 system/lib/libc/emscripten_syscall_stubs.c          | 5 -----
 system/lib/libc/musl/arch/emscripten/bits/syscall.h | 1 -
 system/lib/libc/musl/src/internal/syscall.h         | 6 ++++++
 system/lib/standalone/standalone.c                  | 4 ----
 test/codesize/test_codesize_hello_dylink_all.json   | 2 --
 test/unistd/misc.out                                | 2 +-
 7 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/system/include/emscripten/syscalls.h b/system/include/emscripten/syscalls.h
index 218a8bad4281e..a01c138c05b5d 100644
--- a/system/include/emscripten/syscalls.h
+++ b/system/include/emscripten/syscalls.h
@@ -19,7 +19,6 @@ int __syscall_chdir(intptr_t path);
 int __syscall_mknod(intptr_t path, int mode, int dev);
 int __syscall_chmod(intptr_t path, int mode);
 int __syscall_getpid(void);
-int __syscall_pause(void);
 int __syscall_access(intptr_t path, int amode);
 int __syscall_sync(void);
 int __syscall_rmdir(intptr_t path);
diff --git a/system/lib/libc/emscripten_syscall_stubs.c b/system/lib/libc/emscripten_syscall_stubs.c
index 5f5b23ef35a92..809027da5a03a 100644
--- a/system/lib/libc/emscripten_syscall_stubs.c
+++ b/system/lib/libc/emscripten_syscall_stubs.c
@@ -180,11 +180,6 @@ weak int __syscall_getresgid32(intptr_t ruid, intptr_t euid, intptr_t suid) {
   return 0;
 }
 
-weak int __syscall_pause() {
-  REPORT(pause);
-  return -EINTR; // we can't pause
-}
-
 weak int __syscall_madvise(intptr_t addr, size_t length, int advice) {
   REPORT(madvise);
   // advice is welcome, but ignored
diff --git a/system/lib/libc/musl/arch/emscripten/bits/syscall.h b/system/lib/libc/musl/arch/emscripten/bits/syscall.h
index e3465a65c7406..f78cf22e63536 100644
--- a/system/lib/libc/musl/arch/emscripten/bits/syscall.h
+++ b/system/lib/libc/musl/arch/emscripten/bits/syscall.h
@@ -1,7 +1,6 @@
 #define SYS_chdir		 __syscall_chdir
 #define SYS_chmod		 __syscall_chmod
 #define SYS_getpid		 __syscall_getpid
-#define SYS_pause		 __syscall_pause
 #define SYS_sync		 __syscall_sync
 #define SYS_rmdir		 __syscall_rmdir
 #define SYS_dup		 __syscall_dup
diff --git a/system/lib/libc/musl/src/internal/syscall.h b/system/lib/libc/musl/src/internal/syscall.h
index be10369af0b8e..d957750cf1bd9 100644
--- a/system/lib/libc/musl/src/internal/syscall.h
+++ b/system/lib/libc/musl/src/internal/syscall.h
@@ -430,6 +430,12 @@ hidden long __syscall_ret(unsigned long),
 #ifdef SYS_pause
 #define __sys_pause() __syscall(SYS_pause)
 #define __sys_pause_cp() __syscall_cp(SYS_pause)
+#elif defined(__EMSCRIPTEN__)
+/* Note: When the sigmask argument is NULL, ppoll() differs from poll() only
+ * in the precision of the timeout argument.  For poll -1 means block forever
+ * as opposed to ppoll which uses NULL/0. */
+#define __sys_pause() __syscall(SYS_poll, 0, 0, -1)
+#define __sys_pause_cp() __syscall_cp(SYS_poll, 0, 0, -1)
 #else
 #define __sys_pause() __syscall(SYS_ppoll, 0, 0, 0, 0)
 #define __sys_pause_cp() __syscall_cp(SYS_ppoll, 0, 0, 0, 0)
diff --git a/system/lib/standalone/standalone.c b/system/lib/standalone/standalone.c
index 87e6a9d20bcbe..755049544e0b7 100644
--- a/system/lib/standalone/standalone.c
+++ b/system/lib/standalone/standalone.c
@@ -115,10 +115,6 @@ weak int __syscall_newfstatat(int dirfd, intptr_t path, intptr_t buf, int flags)
   return -ENOSYS;
 }
 
-weak int __syscall_pause() {
-  return -ENOSYS;
-}
-
 weak int __syscall_lstat64(intptr_t path, intptr_t buf) {
   return -ENOSYS;
 }
diff --git a/test/codesize/test_codesize_hello_dylink_all.json b/test/codesize/test_codesize_hello_dylink_all.json
index 6a0721e75b93f..c7ef6b6852523 100644
--- a/test/codesize/test_codesize_hello_dylink_all.json
+++ b/test/codesize/test_codesize_hello_dylink_all.json
@@ -2219,7 +2219,6 @@
     "__syscall_munlock",
     "__syscall_munlockall",
     "__syscall_munmap",
-    "__syscall_pause",
     "__syscall_prlimit64",
     "__syscall_recvmmsg",
     "__syscall_sendmmsg",
@@ -4089,7 +4088,6 @@
     "$__syscall_mremap",
     "$__syscall_msync",
     "$__syscall_munmap",
-    "$__syscall_pause",
     "$__syscall_prlimit64",
     "$__syscall_recvmmsg",
     "$__syscall_setdomainname",
diff --git a/test/unistd/misc.out b/test/unistd/misc.out
index 4ed4b37a3b5fd..0fa3ae2deeff9 100644
--- a/test/unistd/misc.out
+++ b/test/unistd/misc.out
@@ -10,7 +10,7 @@ link: -1, errno: 34
 lockf(good): 0, errno: 0
 lockf(bad): -1, errno: 8
 nice: -1, errno: 63
-pause: -1, errno: 27
+pause: 0, errno: 0
 pipe(good): 0, errno: 0
 pipe(bad): -1, errno: 21
 pipe2(good): 0, errno: 0