Fix GH-11188: Error when building TSRM in ARM64 (for IR JIT) (#14459)

This is GH-11236 for IR JIT.

Author: nielsdos

TSRM/TSRM.c

@@ -800,11 +800,20 @@ TSRM_API size_t tsrm_get_ls_cache_tcb_offset(void)
 	asm("adrp %0, #__tsrm_ls_cache@TLVPPAGE\n\t"
 	    "ldr %0, [%0, #__tsrm_ls_cache@TLVPPAGEOFF]"
 	     : "=r" (ret));
-# else
+# elif defined(TSRM_TLS_MODEL_DEFAULT)
+	/* Surplus Static TLS space isn't guaranteed. */
+	ret = 0;
+# elif defined(TSRM_TLS_MODEL_INITIAL_EXEC)
+	asm("adrp %0, :gottprel:_tsrm_ls_cache\n\t"
+		"ldr %0, [%0, #:gottprel_lo12:_tsrm_ls_cache]"
+		: "=r" (ret));
+# elif defined(TSRM_TLS_MODEL_LOCAL_EXEC)
 	asm("mov %0, xzr\n\t"
 	    "add %0, %0, #:tprel_hi12:_tsrm_ls_cache, lsl #12\n\t"
 	    "add %0, %0, #:tprel_lo12_nc:_tsrm_ls_cache"
 	     : "=r" (ret));
+# else
+#  error "TSRM TLS model not set"
 # endif
 	return ret;
 #else

TSRM/TSRM.h

@@ -154,10 +154,13 @@ TSRM_API bool tsrm_is_managed_thread(void);
 
 #if !__has_attribute(tls_model) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__MUSL__) || defined(__HAIKU__)
 # define TSRM_TLS_MODEL_ATTR
+# define TSRM_TLS_MODEL_DEFAULT
 #elif __PIC__
 # define TSRM_TLS_MODEL_ATTR __attribute__((tls_model("initial-exec")))
+# define TSRM_TLS_MODEL_INITIAL_EXEC
 #else
 # define TSRM_TLS_MODEL_ATTR __attribute__((tls_model("local-exec")))
+# define TSRM_TLS_MODEL_LOCAL_EXEC
 #endif
 
 #define TSRM_SHUFFLE_RSRC_ID(rsrc_id)		((rsrc_id)+1)

ext/opcache/jit/zend_jit_ir.c

@@ -352,6 +352,15 @@ static void* zend_jit_stub_handlers[sizeof(zend_jit_stubs) / sizeof(zend_jit_stu
 
 #if defined(IR_TARGET_AARCH64)
 
+# ifdef __FreeBSD__
+/* https://github.com/freebsd/freebsd-src/blob/c52ca7dd09066648b1cc40f758289404d68ab886/libexec/rtld-elf/aarch64/reloc.c#L180-L184 */
+typedef struct TLSDescriptor {
+	void*   thunk;
+	int     index;
+	size_t  offset;
+} TLSDescriptor;
+# endif
+
 #define IR_HAS_VENEERS (1U<<31) /* IR_RESERVED_FLAG_1 */
 
 static const void *zend_jit_get_veneer(ir_ctx *ctx, const void *addr)
@@ -3185,7 +3194,28 @@ static void zend_jit_setup(void)
 #ifdef ZTS
 #if defined(IR_TARGET_AARCH64)
 	tsrm_ls_cache_tcb_offset = tsrm_get_ls_cache_tcb_offset();
+
+# ifdef __FreeBSD__
+	if (tsrm_ls_cache_tcb_offset == 0) {
+		TLSDescriptor **where;
+
+		__asm__(
+			"adrp %0, :tlsdesc:_tsrm_ls_cache\n"
+			"add %0, %0, :tlsdesc_lo12:_tsrm_ls_cache\n"
+			: "=r" (where));
+		/* See https://github.com/ARM-software/abi-aa/blob/2a70c42d62e9c3eb5887fa50b71257f20daca6f9/aaelf64/aaelf64.rst
+		 * section "Relocations for thread-local storage".
+		 * The first entry holds a pointer to the variable's TLS descriptor resolver function and the second entry holds
+		 * a platform-specific offset or pointer. */
+		TLSDescriptor *tlsdesc = where[1];
+
+		tsrm_tls_offset = tlsdesc->offset;
+		/* Index is offset by 1 on FreeBSD (https://github.com/freebsd/freebsd-src/blob/22ca6db50f4e6bd75a141f57cf953d8de6531a06/lib/libc/gen/tls.c#L88) */
+		tsrm_tls_index = (tlsdesc->index + 1) * 8;
+	}
+# else
 	ZEND_ASSERT(tsrm_ls_cache_tcb_offset != 0);
+# endif
 # elif defined(_WIN64)
 	tsrm_tls_index  = _tls_index * sizeof(void*);