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Clean up the TLS code

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Justine Tunney 2022-09-10 11:49:13 -07:00
parent cfcf5918bc
commit 333768440c
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GPG key ID: BE714B4575D6E328
8 changed files with 81 additions and 21 deletions
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11
libc/runtime/enable_tls.c
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@ -21,6 +21,8 @@
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/intrin/asan.internal.h"
#include "libc/intrin/asancodes.h"
#include "libc/intrin/bits.h"
#include "libc/intrin/weaken.h"
#include "libc/log/libfatal.internal.h"
@ -57,7 +59,7 @@ __msabi extern typeof(TlsAlloc) *const __imp_TlsAlloc;
extern unsigned char __tls_mov_nt_rax[];
extern unsigned char __tls_add_nt_rax[];
_Alignas(long) static char __static_tls[5008];
_Alignas(TLS_ALIGNMENT) static char __static_tls[5008];
/**
* Enables thread local storage for main process.
@ -103,7 +105,6 @@ privileged void __enable_tls(void) {
// if tls requirement is small then use the static tls block
// which helps avoid a system call for appes with little tls
// this is crucial to keeping life.com 16 kilobytes in size!
_Static_assert(alignof(__static_tls) >= alignof(struct CosmoTib));
mem = __static_tls;
} else {
// if this binary needs a hefty tls block then we'll bank on
@ -115,6 +116,12 @@ privileged void __enable_tls(void) {
mem = weaken(_mapanon)(siz);
assert(mem);
}
if (IsAsan()) {
// poison the space between .tdata and .tbss
__asan_poison(mem + (intptr_t)_tdata_size,
(intptr_t)_tbss_offset - (intptr_t)_tdata_size,
kAsanProtected);
}
tib = (struct CosmoTib *)(mem + siz - _TIBZ);
tls = mem + siz - _TIBZ - _TLSZ;
tib->tib_self = tib;

2
libc/runtime/internal.h
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@ -23,6 +23,8 @@ extern unsigned char _tdata_end[];
extern unsigned char _tdata_size[];
extern unsigned char _tbss_start[];
extern unsigned char _tbss_end[];
extern unsigned char _tbss_size[];
extern unsigned char _tbss_offset[];
extern unsigned char _tls_size[];
extern unsigned char _tls_content[];