From cf989374e986462fef70fe4c1d0f5869b194148d Mon Sep 17 00:00:00 2001
From: Pat Tullmann <pat.github@tullmann.org>
Date: Thu, 24 Apr 2025 22:02:53 -0700
Subject: [PATCH] linux: update `sigmask` in every arch `ucontext_t`

All the existing code that manipulates `ucontext_t` expects there to be a
glibc-compatible sigmask (1024-bit).  The `ucontext_t` struct need to be
cleaned up so the glibc-dependent format is only used when linking
glibc/musl library, but that is a more involved change.

In practice, no Zig code looks at the sigset field contents, so it just
needs to be the right size.
---
 lib/std/os/linux/aarch64.zig     | 2 +-
 lib/std/os/linux/arm.zig         | 2 +-
 lib/std/os/linux/loongarch64.zig | 3 +--
 lib/std/os/linux/powerpc.zig     | 2 +-
 lib/std/os/linux/powerpc64.zig   | 2 +-
 lib/std/os/linux/s390x.zig       | 2 +-
 lib/std/os/linux/sparc64.zig     | 2 +-
 lib/std/os/linux/x86.zig         | 2 +-
 8 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/lib/std/os/linux/aarch64.zig b/lib/std/os/linux/aarch64.zig
index 649e474310..ed40145e1b 100644
--- a/lib/std/os/linux/aarch64.zig
+++ b/lib/std/os/linux/aarch64.zig
@@ -289,7 +289,7 @@ pub const ucontext_t = extern struct {
     flags: usize,
     link: ?*ucontext_t,
     stack: stack_t,
-    sigmask: sigset_t,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
     mcontext: mcontext_t,
 };
 
diff --git a/lib/std/os/linux/arm.zig b/lib/std/os/linux/arm.zig
index 8f83bb60a1..8fea30a5da 100644
--- a/lib/std/os/linux/arm.zig
+++ b/lib/std/os/linux/arm.zig
@@ -337,7 +337,7 @@ pub const ucontext_t = extern struct {
     link: ?*ucontext_t,
     stack: stack_t,
     mcontext: mcontext_t,
-    sigmask: sigset_t,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
     regspace: [64]u64,
 };
 
diff --git a/lib/std/os/linux/loongarch64.zig b/lib/std/os/linux/loongarch64.zig
index 9ee8fe229c..50c4664ac8 100644
--- a/lib/std/os/linux/loongarch64.zig
+++ b/lib/std/os/linux/loongarch64.zig
@@ -264,8 +264,7 @@ pub const ucontext_t = extern struct {
     flags: c_ulong,
     link: ?*ucontext_t,
     stack: stack_t,
-    sigmask: sigset_t,
-    _pad: [1024 / 8 - @sizeOf(sigset_t)]u8,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
     mcontext: mcontext_t,
 };
 
diff --git a/lib/std/os/linux/powerpc.zig b/lib/std/os/linux/powerpc.zig
index 443a32769a..450cb27c7e 100644
--- a/lib/std/os/linux/powerpc.zig
+++ b/lib/std/os/linux/powerpc.zig
@@ -341,7 +341,7 @@ pub const ucontext_t = extern struct {
     stack: stack_t,
     pad: [7]i32,
     regs: *mcontext_t,
-    sigmask: sigset_t,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
     pad2: [3]i32,
     mcontext: mcontext_t,
 };
diff --git a/lib/std/os/linux/powerpc64.zig b/lib/std/os/linux/powerpc64.zig
index bb1032fb21..b0a14ff3cb 100644
--- a/lib/std/os/linux/powerpc64.zig
+++ b/lib/std/os/linux/powerpc64.zig
@@ -337,7 +337,7 @@ pub const ucontext_t = extern struct {
     flags: u32,
     link: ?*ucontext_t,
     stack: stack_t,
-    sigmask: sigset_t,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
     mcontext: mcontext_t,
 };
 
diff --git a/lib/std/os/linux/s390x.zig b/lib/std/os/linux/s390x.zig
index 70cf53f6fd..614c33d076 100644
--- a/lib/std/os/linux/s390x.zig
+++ b/lib/std/os/linux/s390x.zig
@@ -273,7 +273,7 @@ pub const ucontext_t = extern struct {
     link: ?*ucontext_t,
     stack: stack_t,
     mcontext: mcontext_t,
-    sigmask: sigset_t,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
 };
 
 pub const mcontext_t = extern struct {
diff --git a/lib/std/os/linux/sparc64.zig b/lib/std/os/linux/sparc64.zig
index 594b11b7ac..34df73fcb1 100644
--- a/lib/std/os/linux/sparc64.zig
+++ b/lib/std/os/linux/sparc64.zig
@@ -454,7 +454,7 @@ pub const ucontext_t = extern struct {
     sigmask: u64,
     mcontext: mcontext_t,
     stack: stack_t,
-    sigset: sigset_t,
+    sigset: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
 };
 
 /// TODO
diff --git a/lib/std/os/linux/x86.zig b/lib/std/os/linux/x86.zig
index cef0388206..41e1ec7d99 100644
--- a/lib/std/os/linux/x86.zig
+++ b/lib/std/os/linux/x86.zig
@@ -350,7 +350,7 @@ pub const ucontext_t = extern struct {
     link: ?*ucontext_t,
     stack: stack_t,
     mcontext: mcontext_t,
-    sigmask: sigset_t,
+    sigmask: [1024 / @bitSizeOf(c_ulong)]c_ulong, // Currently a libc-compatible (1024-bit) sigmask
     regspace: [64]u64,
 };