*
* @APPLE_LICENSE_HEADER_END@
*/
-/*
- Implementation of the "objc runtime pages", an fixed area
- in high memory that can be reached via an absolute branch.
-*/
#import "objc-private.h"
#import <objc/message.h>
-#if defined(__ppc__)
-
-static size_t rtp_copy_code(unsigned* dest, unsigned* source, size_t max_insns);
-static void rtp_set_up_objc_msgSend(uintptr_t address, size_t maxsize);
-static void rtp_set_up_other(uintptr_t address, size_t maxsize, const char *name, void *gc_code, void *non_gc_code);
-
-/**********************************************************************
-* rtp_init
-* Allocate and initialize the Objective-C runtime pages.
-* Kills the process if something goes wrong.
-**********************************************************************/
-__private_extern__ void rtp_init(void)
-{
- kern_return_t ret;
- vm_address_t objcRTPages = (vm_address_t)(kRTPagesHi - kRTPagesSize);
-
- if (PrintRTP) {
- _objc_inform("RTP: initializing rtp at [%p..%p)",
- (void *)objcRTPages, (void *)kRTPagesHi);
- }
-
- // unprotect the ObjC runtime pages for writing
- ret = vm_protect(mach_task_self(),
- objcRTPages, kRTPagesSize,
- FALSE, VM_PROT_READ | VM_PROT_WRITE);
-
- if (ret != KERN_SUCCESS) {
- if (PrintRTP) {
- _objc_inform("RTP: warning: libSystem/kernel did not allocate Objective-C runtime pages; continuing anyway");
- }
- return;
- }
-
- // initialize code in ObjC runtime pages
- rtp_set_up_objc_msgSend(kRTAddress_objc_msgSend, kRTSize_objc_msgSend);
-#ifdef NO_GC
- #define objc_assign_ivar_gc objc_assign_ivar_non_gc
- #define objc_assign_global_gc objc_assign_global_non_gc
- #define objc_assign_strongCast_gc objc_assign_strongCast_non_gc
-#endif
- rtp_set_up_other(kRTAddress_objc_assign_ivar, kRTSize_objc_assign_ivar,
- "objc_assign_ivar", objc_assign_ivar_gc, objc_assign_ivar_non_gc);
-
- rtp_set_up_other(kRTAddress_objc_assign_global, kRTSize_objc_assign_global,
- "objc_assign_global", objc_assign_global_gc, objc_assign_global_non_gc);
-
- rtp_set_up_other(kRTAddress_objc_assign_strongCast, kRTSize_objc_assign_strongCast,
- "objc_assign_strongCast", objc_assign_strongCast_gc, objc_assign_strongCast_non_gc);
-
- // initialize data in ObjC runtime pages
- memset((char *)kRTAddress_zero, 0, 16);
- strlcpy((char *)kIgnore, "<ignored selector>", OBJC_SIZE_T(19));
-
- // re-protect the ObjC runtime pages for execution
- ret = vm_protect(mach_task_self(),
- objcRTPages, kRTPagesSize,
- FALSE, VM_PROT_READ | VM_PROT_EXECUTE);
- if (ret != KERN_SUCCESS) {
- _objc_inform("RTP: Could not re-protect Objective-C runtime pages!");
- }
-}
-
-
-/**********************************************************************
-* rtp_set_up_objc_msgSend
-*
-* Construct the objc runtime page version of objc_msgSend
-* address is the entry point of the new implementation.
-* maxsize is the number of bytes available for the new implementation.
-**********************************************************************/
-static void rtp_set_up_objc_msgSend(uintptr_t address, size_t maxsize)
-{
- // Location in the runtime pages of the new function.
- unsigned *buffer = (unsigned *)address;
-
- // Location of the original implementation.
- // objc_msgSend is simple enough to copy directly
- unsigned *code = (unsigned *)objc_msgSend;
-
- // If building an instrumented or profiled runtime, simply branch
- // directly to the full implementation.
-#if defined(OBJC_INSTRUMENTED) || defined(PROFILE)
- size_t written = objc_write_branch(buffer, code);
- sys_icache_invalidate(buffer, written*4);
- if (PrintRTP) {
- _objc_inform("RTP: instrumented or profiled libobjc - objc_msgSend "
- "in RTP at %p is a %zu instruction branch",
- buffer, written);
- }
- return;
-#endif
-
- if (PrintRTP) {
- _objc_inform("RTP: writing objc_msgSend at [%p..%p) ...",
- (void *)address, (void *)(address+maxsize));
- }
-
- // Copy instructions from function to runtime pages
- // i is the number of INSTRUCTIONS written so far
- size_t max_insns = maxsize / sizeof(unsigned);
- size_t i = rtp_copy_code(buffer, code, max_insns);
- if (i + objc_branch_size(buffer + i, code + i) > max_insns) {
- // objc_msgSend didn't fit in the alloted space.
- // Branch to ordinary objc_msgSend instead so the program won't crash.
- i = objc_write_branch(buffer, code);
- sys_icache_invalidate(buffer, i*4);
- _objc_inform("RTP: objc_msgSend is too large to fit in the "
- "runtime pages (%zu bytes available)", maxsize);
- return;
- }
-
- {
- // Replace load of _objc_nilReceiver into r11
- // This assumes that the load of _objc_nilReceiver
- // immediately follows the LAST `mflr r0` in objc_msgSend,
- // and that the original load sequence is six instructions long.
-
- // instructions used to load _objc_nilReceiver
- const unsigned op_mflr_r0 = 0x7c0802a6u;
- const unsigned op_nop = 0x60000000u;
-
- // get address of _objc_nilReceiver, and its lo and hi halves
- uintptr_t address = (uintptr_t)&_objc_nilReceiver;
- uint16_t lo = address & 0xffff;
- uint16_t ha = ((address - (int16_t)lo) >> 16) & 0xffff;
-#if defined(__ppc64__)
- uint16_t hi2 = (address >> 32) & 0xffff;
- uint16_t hi3 = (address >> 48) & 0xffff;
-#endif
-
- // search for mflr instruction
- size_t j;
- for (j = i; j-- != 0; ) {
- if (buffer[j] == op_mflr_r0) {
- const unsigned op_lis_r11 = 0x3d600000u;
- const unsigned op_lwz_r11 = 0x816b0000u;
-#if defined(__ppc__)
- // lis r11, ha
- // lwz r11, lo(r11)
- buffer[j + 0] = op_lis_r11 | ha;
- buffer[j + 1] = op_nop;
- buffer[j + 2] = op_nop;
- buffer[j + 3] = op_lwz_r11 | lo;
- buffer[j + 4] = op_nop;
- buffer[j + 5] = op_nop;
-#elif defined(__ppc64__)
- const unsigned op_ori_r11 = 0x616b0000u;
- const unsigned op_oris_r11 = 0x656b0000u;
- const unsigned op_sldi_r11 = 0x796b07c6u;
- // lis r11, hi3
- // ori r11, r11, hi2
- // sldi r11, r11, 32
- // oris r11, r11, ha
- // lwz r11, lo(r11)
- buffer[j + 0] = op_lis_r11 | hi3;
- buffer[j + 1] = op_ori_r11 | hi2;
- buffer[j + 2] = op_sldi_r11;
- buffer[j + 3] = op_oris_r11 | ha;
- buffer[j + 4] = op_lwz_r11 | lo;
- buffer[j + 5] = op_nop;
-#endif
- break;
- }
- }
- }
-
- // branch to the cache miss code
- i += objc_write_branch(buffer + i, code + i);
-
- // flush the instruction cache
- sys_icache_invalidate(buffer, i*4);
-
- if (PrintRTP) {
- _objc_inform("RTP: wrote objc_msgSend at [%p..%p)",
- (void *)address, (void *)(address + i*sizeof(unsigned)));
- }
-}
-
-
-/**********************************************************************
-* rtp_set_up_other
-*
-* construct the objc runtime page version of the supplied code
-* address is the entry point of the new implementation.
-* maxsize is the number of bytes available for the new implementation.
-* name is the c string name of the routine being set up.
-* gc_code is the code to use if collecting is enabled (assumed to be large and requiring a branch.)
-* non_gc_code is the code to use if collecting is not enabled (assumed to be small enough to copy.)
-**********************************************************************/
-static void rtp_set_up_other(uintptr_t address, size_t maxsize, const char *name, void *gc_code, void *non_gc_code) {
- // location in the runtime pages of this function
- unsigned *buffer = (unsigned *)address;
-
- // Location of the original implementation.
- unsigned *code = (unsigned *)(objc_collecting_enabled() ? gc_code : non_gc_code);
-
- if (objc_collecting_enabled()) {
- size_t written = objc_write_branch(buffer, code);
- sys_icache_invalidate(buffer, written*4);
- if (PrintRTP) {
- _objc_inform("RTP: %s in RTP at %p is a %zu instruction branch",
- name, buffer, written);
- }
- return;
- }
-
- if (PrintRTP) {
- _objc_inform("RTP: writing %s at [%p..%p) ...",
- name, (void *)address, (void *)(address + maxsize));
- }
-
- // Copy instructions from function to runtime pages
- // i is the number of INSTRUCTIONS written so far
- size_t max_insns = maxsize / sizeof(unsigned);
- size_t i = rtp_copy_code(buffer, code, max_insns);
- if (i > max_insns) {
- // code didn't fit in the alloted space.
- // Branch to ordinary objc_assign_ivar instead so the program won't crash.
- i = objc_write_branch(buffer, code);
- sys_icache_invalidate(buffer, i*4);
- _objc_inform("RTP: %s is too large to fit in the "
- "runtime pages (%zu bytes available)", name, maxsize);
- return;
- }
-
- // flush the instruction cache
- sys_icache_invalidate(buffer, i*4);
-
- if (PrintRTP) {
- _objc_inform("RTP: wrote %s at [%p..%p)",
- name, (void *)address,
- (void *)(address + i * sizeof(unsigned)));
- }
-}
-
-
-/**********************************************************************
-* rtp_copy_code
-*
-* Copy blr-terminated PPC instructions from source to dest.
-* If a blr is reached then that blr is copied, and the return value is
-* the number of instructions copied ( <= max_insns )
-* If no blr is reached then exactly max_insns instructions are copied,
-* and the return value is max_insns+1.
-**********************************************************************/
-static size_t rtp_copy_code(unsigned* dest, unsigned* source, size_t max_insns)
-{
- const unsigned op_blr = 0x4e800020u;
- size_t i;
-
- // copy instructions until blr is found
- for (i = 0; i < max_insns; i++) {
- dest[i] = source[i];
- if (source[i] == op_blr) break;
- }
-
- // return number of instructions copied
- // OR max_insns+1 if no blr was found
- return i + 1;
-}
-
-
-#elif defined(__i386__)
+#if defined(__i386__)
/**********************************************************************
}
-__private_extern__ void rtp_init(void)
+PRIVATE_EXTERN void rtp_init(void)
{
// At load time, the page on which the objc_assign_* routines live is not
// marked as executable. We fix that here, regardless of the GC choice.
-#ifndef NO_GC
+#if SUPPORT_GC
if (UseGC)
{
rtp_swap_imp((unsigned*)objc_assign_ivar,
objc_assign_ivar_gc, "objc_assign_ivar");
rtp_swap_imp((unsigned*)objc_assign_global,
objc_assign_global_gc, "objc_assign_global");
+ rtp_swap_imp((unsigned*)objc_assign_threadlocal,
+ objc_assign_threadlocal_gc, "objc_assign_threadlocal");
rtp_swap_imp((unsigned*)objc_assign_strongCast,
objc_assign_strongCast_gc, "objc_assign_strongCast");
}
#else
-__private_extern__ void rtp_init(void)
+PRIVATE_EXTERN void rtp_init(void)
{
if (PrintRTP) {
_objc_inform("RTP: no rtp implementation for this platform");
projects / apple / objc4.git / blobdiff