mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2025-12-16 03:03:09 +00:00
Code Issues Packages Projects Releases Wiki Activity

start.zig: intentional silent failure when cannot increase stack size

Browse Source
This commit is contained in:
Andrew Kelley 2021-05-28 13:17:04 -07:00
parent 673ae5b457
commit 33a779c7f6
1 changed files with 12 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
lib/std/start.zig
View File

@ -297,9 +297,10 @@ fn posixCallMainAndExit() noreturn {
std.os.linux.tls.initStaticTLS();
}
// Linux ignores the stack size from the ELF file, and instead always gives 8 MiB.
// Here we look for the stack size in our program headers and tell the kernel,
// no, seriously, give me that stack space, I wasn't joking.
// The way Linux executables represent stack size is via the PT_GNU_STACK
// program header. However the kernel does not recognize it; it always gives 8 MiB.
// Here we look for the stack size in our program headers and use setrlimit
// to ask for more stack space.
{
var i: usize = 0;
var at_phdr: usize = undefined;
@ -330,15 +331,14 @@ fn expandStackSize(at_phdr: usize, at_phnum: usize) void {
.cur = wanted_stack_size,
.max = wanted_stack_size,
}) catch {
// If this is a debug build, it will be useful to find out
// why this failed. If it is a release build, we allow the
// stack overflow to cause a segmentation fault. Memory safety
// is not compromised, however, depending on runtime state,
// the application may crash due to provided stack space not
// matching the known upper bound.
if (builtin.mode == .Debug) {
@panic("unable to increase stack size");
}
// Because we could not increase the stack size to the upper bound,
// depending on what happens at runtime, a stack overflow may occur.
// However it would cause a segmentation fault, thanks to stack probing,
// so we do not have a memory safety issue here.
// This is intentional silent failure.
// This logic should be revisited when the following issues are addressed:
// https://github.com/ziglang/zig/issues/157
// https://github.com/ziglang/zig/issues/1006
};
break;
},