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JIT: Fix TLS access with SHM reattachment (8.6 follow-up) #24456

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JIT: Fix TLS access with SHM reattachment (8.6 follow-up) #24456

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d0d8754
JIT: Fix TLS access with SHM reattachment (8.6 follow-up)
arnaud-lb Oct 19, 2026
e8e9a07
Fix build
arnaud-lb Oct 20, 2026
07ddedc
ir_TLS()
arnaud-lb Oct 20, 2026
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26 changes: 21 additions & 5 deletions ext/opcache/jit/zend_jit_ir.c
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Original file line number Diff line number Diff line change
Expand Up @@ -360,6 +360,8 @@ static int zend_jit_assign_to_variable(zend_jit_ctx *jit,

static ir_ref jit_CONST_FUNC(zend_jit_ctx *jit, uintptr_t addr, uint16_t flags);

static ir_ref jit_ADD_OFFSET(zend_jit_ctx *jit, ir_ref addr, uintptr_t offset);
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static void zend_jit_preserve_parent_regs(zend_jit_ctx *jit,
zend_ssa *ssa,
zend_jit_trace_info *parent,
Expand Down Expand Up @@ -522,9 +524,28 @@ static ir_ref jit_TLS(zend_jit_ctx *jit)
if (tsrm_ls_cache_tcb_offset == 0 && tsrm_tls_index == -1) {
jit->tls = ir_CALL(IR_ADDR, ir_CONST_FC_FUNC(zend_jit_get_tsrm_ls_cache));
} else {
# ifdef ZEND_OPCACHE_SHM_REATTACHMENT
/* Different processes may load TLS variables in a different order, so
* they may have a different module index. Fetch the module index at
* runtime from tsrm_tls_index. Its address is stable as it's in the same
* module as execute_ex (whose address is checked before SHM reattachment). */

# ifdef _WIN64
const int offset = 0x58;
# else
const int offset = 0x2c;
# endif

/* NtCurrentTeb()->ThreadLocalStoragePointer */
ir_ref tls_array = ir_TLS(-1, offset);

ir_ref index = ir_LOAD_A(ir_CONST_ADDR(&tsrm_tls_index));
jit->tls = ir_LOAD_A(ir_ADD_OFFSET(ir_LOAD_A(ir_ADD_A(tls_array, index)), tsrm_tls_offset));
# else
jit->tls = ir_TLS(
tsrm_ls_cache_tcb_offset ? tsrm_ls_cache_tcb_offset : tsrm_tls_index,
tsrm_ls_cache_tcb_offset ? IR_NULL : tsrm_tls_offset);
# endif
}

return jit->tls;
Expand Down Expand Up @@ -3432,10 +3453,6 @@ static void zend_jit_setup(bool reattached)
#endif

#ifdef ZTS
# ifdef ZEND_OPCACHE_SHM_REATTACHMENT
/* Different processes may load TLS variables in a different order, so we
* can not rely on offsets. We will fallback to runtime resolution. */
# else
zend_result result = zend_jit_resolve_tsrm_ls_cache_offsets(
&tsrm_ls_cache_tcb_offset,
&tsrm_tls_index,
Expand All @@ -3445,7 +3462,6 @@ static void zend_jit_setup(bool reattached)
zend_accel_error(ACCEL_LOG_INFO,
"Could not get _tsrm_ls_cache offsets, will fallback to runtime resolution");
}
# endif
#endif

#if !defined(ZEND_WIN32) && !defined(IR_TARGET_AARCH64)
Expand Down
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