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| author | Alex Rønne Petersen <alex@alexrp.com> | 2024-07-24 17:38:54 +0200 |
|---|---|---|
| committer | Alex Rønne Petersen <alex@alexrp.com> | 2024-07-24 20:12:14 +0200 |
| commit | 5c96192c196c3a43f43de26c8256ed9a784f5140 (patch) | |
| tree | a0a7ba035a22f8e0596360551c2771b8b201746c /lib/std | |
| parent | 4de8bba648c6ab9e2f3a05f3f90ba6524520d3c0 (diff) | |
| download | zig-5c96192c196c3a43f43de26c8256ed9a784f5140.tar.gz zig-5c96192c196c3a43f43de26c8256ed9a784f5140.zip | |
start: Add a comment explaining our paranoid stance on ABI guarantees.
Diffstat (limited to 'lib/std')
| -rw-r--r-- | lib/std/start.zig | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/std/start.zig b/lib/std/start.zig index 9d4edd16bf..21baacc764 100644 --- a/lib/std/start.zig +++ b/lib/std/start.zig @@ -272,6 +272,12 @@ fn _start() callconv(.Naked) noreturn { : [tos] "={rax}" (-> *std.os.plan9.Tos), ); } + + // Note that we maintain a very low level of trust with regards to ABI guarantees at this point. + // We will redundantly align the stack, clear the link register, etc. While e.g. the Linux + // kernel is usually good about upholding the ABI guarantees, the same cannot be said of dynamic + // linkers; musl's ldso, for example, opts to not align the stack when invoking the dynamic + // linker explicitly. asm volatile (switch (native_arch) { .x86_64 => \\ xorl %%ebp, %%ebp |