[php-src] PHP-8.6: JIT: Fix TLS access with SHM reattachment (8.6 follow-up) (#24456)

Author: Arnaud Le Blanc (arnaud-lb) Committer: GitHub (web-flow) Pusher: arnaud-lb Date: 2026-10-22T11:43:05+02:00 Commit: https://github.com/php/php-src/commit/46ac97c265bc83aa57fb0f5ad09c863a6978a2da Raw diff: https://github.com/php/php-src/commit/46ac97c265bc83aa57fb0f5ad09c863a6978a2da.diff JIT: Fix TLS access with SHM reattachment (8.6 follow-up) (#24456) Co-Authored-By: ndossche <7771979+ndossche@users.noreply.github.com> Changed paths: M ext/opcache/jit/zend_jit_ir.c Diff: diff --git a/ext/opcache/jit/zend_jit_ir.c b/ext/opcache/jit/zend_jit_ir.c index bde6f8558031..ca7bd8383337 100644 --- a/ext/opcache/jit/zend_jit_ir.c +++ b/ext/opcache/jit/zend_jit_ir.c @@ -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); + static void zend_jit_preserve_parent_regs(zend_jit_ctx *jit, zend_ssa *ssa, zend_jit_trace_info *parent, @@ -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; @@ -3444,10 +3465,6 @@ 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, @@ -3457,7 +3474,6 @@ 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)