diff options
author | rentzsch <jwr.git@redshed.net> | 2012-08-10 07:27:45 +0400 |
---|---|---|
committer | rentzsch <jwr.git@redshed.net> | 2012-08-10 07:27:45 +0400 |
commit | 1b3aa46fc36ea65ad6294379df54fad13a7b27a6 (patch) | |
tree | 57d297c23d6cb600a049e8eff01d18049e578f71 | |
parent | bc77809297a3a200ad10b1ccabcd0d4ca409ae59 (diff) |
Back out https://github.com/rentzsch/mach_star/pull/38
and https://github.com/rentzsch/mach_star/pull/39.
They were causing basic tests to fail (10.8 x86_64).
-rw-r--r-- | mach_override.c | 137 |
1 files changed, 80 insertions, 57 deletions
diff --git a/mach_override.c b/mach_override.c index fc04cc2..64dd0ab 100644 --- a/mach_override.c +++ b/mach_override.c @@ -23,7 +23,6 @@ #pragma mark - #pragma mark (Constants) -#define kPageSize 4096 #if defined(__ppc__) || defined(__POWERPC__) long kIslandTemplate[] = { @@ -77,6 +76,9 @@ char kIslandTemplate[] = { #endif +#define kAllocateHigh 1 +#define kAllocateNormal 0 + /************************** * * Data Types @@ -87,6 +89,7 @@ char kIslandTemplate[] = { typedef struct { char instructions[sizeof(kIslandTemplate)]; + int allocatedHigh; } BranchIsland; /************************** @@ -100,6 +103,7 @@ typedef struct { mach_error_t allocateBranchIsland( BranchIsland **island, + int allocateHigh, void *originalFunctionAddress); mach_error_t @@ -154,10 +158,12 @@ fixupInstructions( #if defined(__i386__) || defined(__x86_64__) mach_error_t makeIslandExecutable(void *address) { mach_error_t err = err_none; - uintptr_t page = (uintptr_t)address & ~(uintptr_t)(kPageSize-1); + vm_size_t pageSize; + host_page_size( mach_host_self(), &pageSize ); + uintptr_t page = (uintptr_t)address & ~(uintptr_t)(pageSize-1); int e = err_none; - e |= mprotect((void *)page, kPageSize, PROT_EXEC | PROT_READ | PROT_WRITE); - e |= msync((void *)page, kPageSize, MS_INVALIDATE ); + e |= mprotect((void *)page, pageSize, PROT_EXEC | PROT_READ | PROT_WRITE); + e |= msync((void *)page, pageSize, MS_INVALIDATE ); if (e) { err = err_cannot_override; } @@ -235,7 +241,7 @@ mach_override_ptr( // Allocate and target the escape island to the overriding function. BranchIsland *escapeIsland = NULL; if( !err ) - err = allocateBranchIsland( &escapeIsland, originalFunctionAddress ); + err = allocateBranchIsland( &escapeIsland, kAllocateHigh, originalFunctionAddress ); if (err) fprintf(stderr, "err = %x %s:%d\n", err, __FILE__, __LINE__); @@ -277,7 +283,7 @@ mach_override_ptr( // technically our original function. BranchIsland *reentryIsland = NULL; if( !err && originalFunctionReentryIsland ) { - err = allocateBranchIsland( &reentryIsland, escapeIsland); + err = allocateBranchIsland( &reentryIsland, kAllocateHigh, escapeIsland); if( !err ) *originalFunctionReentryIsland = reentryIsland; } @@ -361,6 +367,9 @@ mach_override_ptr( Implementation: Allocates memory for a branch island. @param island <- The allocated island. + @param allocateHigh -> Whether to allocate the island at the end of the + address space (for use with the branch absolute + instruction). @result <- mach_error_t ***************************************************************************/ @@ -368,63 +377,63 @@ mach_override_ptr( mach_error_t allocateBranchIsland( BranchIsland **island, + int allocateHigh, void *originalFunctionAddress) { assert( island ); - assert( sizeof( BranchIsland ) <= kPageSize ); - - vm_map_t task_self = mach_task_self(); - vm_address_t original_address = (vm_address_t) originalFunctionAddress; - static vm_address_t last_allocated = 0; - vm_address_t address = - last_allocated ? last_allocated : original_address; - - for (;;) { - vm_size_t vmsize = 0; - memory_object_name_t object = 0; - kern_return_t kr = 0; - vm_region_flavor_t flavor = VM_REGION_BASIC_INFO; - // Find the page the address is in. -#if __WORDSIZE == 32 - vm_region_basic_info_data_t info; - mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT; - kr = vm_region(task_self, &address, &vmsize, flavor, - (vm_region_info_t)&info, &info_count, &object); + + mach_error_t err = err_none; + + if( allocateHigh ) { + vm_size_t pageSize; + err = host_page_size( mach_host_self(), &pageSize ); + if( !err ) { + assert( sizeof( BranchIsland ) <= pageSize ); +#if defined(__ppc__) || defined(__POWERPC__) + vm_address_t first = 0xfeffffff; + vm_address_t last = 0xfe000000 + pageSize; +#elif defined(__x86_64__) + vm_address_t first = ((uint64_t)originalFunctionAddress & ~(uint64_t)(((uint64_t)1 << 31) - 1)) | ((uint64_t)1 << 31); // start in the middle of the page? + vm_address_t last = 0x0; #else - vm_region_basic_info_data_64_t info; - mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT_64; - kr = vm_region_64(task_self, &address, &vmsize, flavor, - (vm_region_info_t)&info, &info_count, &object); + vm_address_t first = 0xffc00000; + vm_address_t last = 0xfffe0000; #endif - if (kr != KERN_SUCCESS) - return kr; - // Don't underflow. This could be made to work, but this is a - // convenient place to give up. - assert((address & (kPageSize - 1)) == 0); - if (address == 0) - break; + vm_address_t page = first; + int allocated = 0; + vm_map_t task_self = mach_task_self(); + + while( !err && !allocated && page != last ) { - // Go back one page. - vm_address_t new_address = address - kPageSize; -#if __WORDSIZE == 64 - if(original_address - new_address - 5 > INT32_MAX) - break; + err = vm_allocate( task_self, &page, pageSize, 0 ); + if( err == err_none ) + allocated = 1; + else if( err == KERN_NO_SPACE ) { +#if defined(__x86_64__) + page -= pageSize; +#else + page += pageSize; #endif - address = new_address; - - // Try to allocate this page. - kr = vm_allocate(task_self, &address, kPageSize, 0); - if (kr == KERN_SUCCESS) { - *island = (BranchIsland*) address; - last_allocated = address; - return err_none; + err = err_none; + } + } + if( allocated ) + *island = (BranchIsland*) page; + else if( !allocated && !err ) + err = KERN_NO_SPACE; } - if (kr != KERN_NO_SPACE) - return kr; + } else { + void *block = malloc( sizeof( BranchIsland ) ); + if( block ) + *island = block; + else + err = KERN_NO_SPACE; } - - return KERN_NO_SPACE; + if( !err ) + (**island).allocatedHigh = allocateHigh; + + return err; } /***************************************************************************//** @@ -441,9 +450,24 @@ freeBranchIsland( { assert( island ); assert( (*(long*)&island->instructions[0]) == kIslandTemplate[0] ); - assert( sizeof( BranchIsland ) <= kPageSize ); - return vm_deallocate( mach_task_self(), (vm_address_t) island, - kPageSize ); + assert( island->allocatedHigh ); + + mach_error_t err = err_none; + + if( island->allocatedHigh ) { + vm_size_t pageSize; + err = host_page_size( mach_host_self(), &pageSize ); + if( !err ) { + assert( sizeof( BranchIsland ) <= pageSize ); + err = vm_deallocate( + mach_task_self(), + (vm_address_t) island, pageSize ); + } + } else { + free( island ); + } + + return err; } /***************************************************************************//** @@ -570,7 +594,6 @@ static AsmInstructionMatch possibleInstructions[] = { { 0x3, {0xFF, 0xFF, 0xFF}, {0x48, 0x89, 0xE5} }, // mov %rsp,%rbp { 0x4, {0xFF, 0xFF, 0xFF, 0x00}, {0x48, 0x83, 0xEC, 0x00} }, // sub 0x??, %rsp { 0x4, {0xFB, 0xFF, 0x00, 0x00}, {0x48, 0x89, 0x00, 0x00} }, // move onto rbp - { 0x4, {0xFF, 0xFF, 0xFF, 0xFF}, {0x40, 0x0f, 0xbe, 0xce} }, // movsbl %sil, %ecx { 0x2, {0xFF, 0x00}, {0x41, 0x00} }, // push %rXX { 0x2, {0xFF, 0x00}, {0x85, 0x00} }, // test %rX,%rX { 0x5, {0xF8, 0x00, 0x00, 0x00, 0x00}, {0xB8, 0x00, 0x00, 0x00, 0x00} }, // mov $imm, %reg |