From 6dbfba526f7b7cf1256c133d025b11409c97dda7 Mon Sep 17 00:00:00 2001 From: Brandon Black Date: Fri, 12 Sep 2025 07:20:08 -0500 Subject: [PATCH] linux: Doc and check retval for no-fail pid calls The switch from @bitCast() to @intCast() here safety-checks Linux's assertion that these 3 calls never return errors (negative values as pid_t). getppid() can legally return 0 if the parent is in a different pid namespace, but this is not an error. --- lib/std/os/linux.zig | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig index 3319f08fc7..a62655d577 100644 --- a/lib/std/os/linux.zig +++ b/lib/std/os/linux.zig @@ -1839,15 +1839,18 @@ pub fn setsid() usize { } pub fn getpid() pid_t { - return @bitCast(@as(u32, @truncate(syscall0(.getpid)))); + // Casts result to a pid_t, safety-checking >= 0, because getpid() cannot fail + return @intCast(@as(u32, @truncate(syscall0(.getpid)))); } pub fn getppid() pid_t { - return @bitCast(@as(u32, @truncate(syscall0(.getppid)))); + // Casts result to a pid_t, safety-checking >= 0, because getppid() cannot fail + return @intCast(@as(u32, @truncate(syscall0(.getppid)))); } pub fn gettid() pid_t { - return @bitCast(@as(u32, @truncate(syscall0(.gettid)))); + // Casts result to a pid_t, safety-checking >= 0, because gettid() cannot fail + return @intCast(@as(u32, @truncate(syscall0(.gettid)))); } pub fn sigprocmask(flags: u32, noalias set: ?*const sigset_t, noalias oldset: ?*sigset_t) usize {