std.os.linux.x32: fix read of stack slot containing ctid in clone()
It's a 32-bit pointer and passed on the stack; the upper 32 bits of the stack
slot are garbage. This means that we ask the kernel to write to some random
64-bit location, which it will just silently fail to do (the process is in x32
mode; nothing can be mapped up there), and consequently, the thread's child_tid
field will never be populated, causing a later join() to hang.
1 files changed, 1 insertions(+), 1 deletions(-)
lib
lib/std/os/linux/x32.zig+1-1
| ... | ... | @@ -130,7 +130,7 @@ pub fn clone() callconv(.naked) u32 { |
| 130 | 130 | \\ mov %%rdx,%%rdi |
| 131 | 131 | \\ mov %%r8,%%rdx |
| 132 | 132 | \\ mov %%r9,%%r8 |
| 133 | | \\ mov 8(%%rsp),%%r10 |
| 133 | \\ mov 8(%%rsp),%%r10d |
| 134 | 134 | \\ mov %%r11,%%r9 |
| 135 | 135 | \\ and $-16,%%rsi |
| 136 | 136 | \\ sub $8,%%rsi |
Alex Rønne Petersen <alex@alexrp.com> 2026-06-19 08:25:25+02:00
Signed by SSH key SHA256:7B/LJ7bpR1eX8aCXSr4mtd5M45VMPKcx9zY8e95b5QM