Commit 6d23850108

Alex Rønne Petersen <alex@alexrp.com>
2024-08-12 04:10:27
std.Thread: Explain apparently pointless mips instruction in freeAndExit().
https://git.musl-libc.org/cgit/musl/commit/?id=ce3688eca920aa77549323f84e21f33522397115
master
1 parent f988cea
Changed files (1)
lib
std
Thread.zig
lib/std/Thread.zig
@@ -1130,6 +1130,10 @@ const LinuxThreadImpl = struct {
                       [len] "r" (self.mapped.len),
                     : "memory"
                 ),
+                // We set `sp` to the address of the current function as a workaround for a Linux
+                // kernel bug that caused syscalls to return EFAULT if the stack pointer is invalid.
+                // The bug was introduced in 46e12c07b3b9603c60fc1d421ff18618241cb081 and fixed in
+                // 7928eb0370d1133d0d8cd2f5ddfca19c309079d5.
                 .mips, .mipsel => asm volatile (
                     \\  move $sp, $25
                     \\  li $2, 4091 # SYS_munmap