diff options
| -rw-r--r-- | gdb/ChangeLog | 12 | ||||
| -rw-r--r-- | gdb/darwin-nat.c | 14 | ||||
| -rw-r--r-- | gdb/solib-darwin.c | 120 |
3 files changed, 112 insertions, 34 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 269fdce..6a8592e 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,17 @@ 2015-11-23 Tristan Gingold <gingold@adacore.com> + * darwin-nat.c (darwin_read_dyld_info): Write address in + big-endian order. + * solib-darwin.c (darwin_validate_exec_header): New function, + extracted from... + (darwin_read_exec_load_addr_from_dyld): ...here. + (darwin_read_exec_load_addr_at_init): New function. + (darwin_solib_read_all_image_info_addr): Adjust after + darwin_read_dyld_info change. + (darwin_solib_create_inferior_hook): Support PIE. + +2015-11-23 Tristan Gingold <gingold@adacore.com> + * darwin-nat.c (darwin_ptrace): Add a cast to fix warning. (darwin_resume, cancel_breakpoint, _initialize_darwin_inferior): Likewise. diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c index 7ad6b22..cb2b08e 100644 --- a/gdb/darwin-nat.c +++ b/gdb/darwin-nat.c @@ -1965,7 +1965,7 @@ darwin_read_write_inferior (task_t task, CORE_ADDR addr, } /* Read LENGTH bytes at offset ADDR of task_dyld_info for TASK, and copy them - to RDADDR. + to RDADDR (in big endian). Return 0 on failure; number of bytes read / written otherwise. */ #ifdef TASK_DYLD_INFO_COUNT @@ -1979,17 +1979,17 @@ darwin_read_dyld_info (task_t task, CORE_ADDR addr, gdb_byte *rdaddr, int sz = TASK_DYLD_INFO_COUNT * sizeof (natural_t); kern_return_t kret; - if (addr >= sz) + if (addr != 0 || length > sizeof (mach_vm_address_t)) return TARGET_XFER_EOF; - kret = task_info (task, TASK_DYLD_INFO, (task_info_t) &task_dyld_info, &count); + kret = task_info (task, TASK_DYLD_INFO, + (task_info_t) &task_dyld_info, &count); MACH_CHECK_ERROR (kret); if (kret != KERN_SUCCESS) return TARGET_XFER_E_IO; - /* Truncate. */ - if (addr + length > sz) - length = sz - addr; - memcpy (rdaddr, (char *)&task_dyld_info + addr, length); + + store_unsigned_integer (rdaddr, length, BFD_ENDIAN_BIG, + task_dyld_info.all_image_info_addr); *xfered_len = (ULONGEST) length; return TARGET_XFER_OK; } diff --git a/gdb/solib-darwin.c b/gdb/solib-darwin.c index 876ca8c..88a4d73 100644 --- a/gdb/solib-darwin.c +++ b/gdb/solib-darwin.c @@ -326,11 +326,41 @@ darwin_current_sos (void) return head; } -/* Get the load address of the executable. We assume that the dyld info are - correct. */ +/* Check LOAD_ADDR points to a Mach-O executable header. Return LOAD_ADDR + in case of success, 0 in case of failure. */ static CORE_ADDR -darwin_read_exec_load_addr (struct darwin_info *info) +darwin_validate_exec_header (CORE_ADDR load_addr) +{ + enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); + struct mach_o_header_external hdr; + unsigned long hdr_val; + + /* Read Mach-O header from memory. */ + if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4)) + return 0; + + /* Discard wrong magic numbers. Shouldn't happen. */ + hdr_val = extract_unsigned_integer + (hdr.magic, sizeof (hdr.magic), byte_order); + if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64) + return 0; + + /* Check executable. */ + hdr_val = extract_unsigned_integer + (hdr.filetype, sizeof (hdr.filetype), byte_order); + if (hdr_val == BFD_MACH_O_MH_EXECUTE) + return load_addr; + + return 0; +} + +/* Get the load address of the executable using dyld list of images. + We assume that the dyld info are correct (which is wrong if the target + is stopped at the first instruction). */ + +static CORE_ADDR +darwin_read_exec_load_addr_from_dyld (struct darwin_info *info) { struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr; enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); @@ -344,33 +374,47 @@ darwin_read_exec_load_addr (struct darwin_info *info) CORE_ADDR iinfo = info->all_image.info + i * image_info_size; gdb_byte buf[image_info_size]; CORE_ADDR load_addr; - struct mach_o_header_external hdr; - unsigned long hdr_val; /* Read image info from inferior. */ if (target_read_memory (iinfo, buf, image_info_size)) break; load_addr = extract_typed_address (buf, ptr_type); - - /* Read Mach-O header from memory. */ - if (target_read_memory (load_addr, (gdb_byte *) &hdr, sizeof (hdr) - 4)) - break; - /* Discard wrong magic numbers. Shouldn't happen. */ - hdr_val = extract_unsigned_integer - (hdr.magic, sizeof (hdr.magic), byte_order); - if (hdr_val != BFD_MACH_O_MH_MAGIC && hdr_val != BFD_MACH_O_MH_MAGIC_64) - continue; - /* Check executable. */ - hdr_val = extract_unsigned_integer - (hdr.filetype, sizeof (hdr.filetype), byte_order); - if (hdr_val == BFD_MACH_O_MH_EXECUTE) + if (darwin_validate_exec_header (load_addr) == load_addr) return load_addr; } return 0; } +/* Get the load address of the executable when the PC is at the dyld + entry point using parameter passed by the kernel (at SP). */ + +static CORE_ADDR +darwin_read_exec_load_addr_at_init (struct darwin_info *info) +{ + struct gdbarch *gdbarch = target_gdbarch (); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int addr_size = gdbarch_addr_bit (gdbarch) / 8; + ULONGEST load_ptr_addr; + ULONGEST load_addr; + gdb_byte buf[8]; + + /* Get SP. */ + if (regcache_cooked_read_unsigned (get_current_regcache (), + gdbarch_sp_regnum (gdbarch), + &load_ptr_addr) != REG_VALID) + return 0; + + /* Read value at SP (image load address). */ + if (target_read_memory (load_ptr_addr, buf, addr_size)) + return 0; + + load_addr = extract_unsigned_integer (buf, addr_size, byte_order); + + return darwin_validate_exec_header (load_addr); +} + /* Return 1 if PC lies in the dynamic symbol resolution code of the run time loader. */ @@ -438,8 +482,8 @@ darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info) bfd *sub; make_cleanup_bfd_unref (dyld_bfd); - sub = gdb_bfd_mach_o_fat_extract (dyld_bfd, bfd_object, - gdbarch_bfd_arch_info (target_gdbarch ())); + sub = gdb_bfd_mach_o_fat_extract + (dyld_bfd, bfd_object, gdbarch_bfd_arch_info (target_gdbarch ())); if (sub) { dyld_bfd = sub; @@ -472,22 +516,29 @@ darwin_solib_get_all_image_info_addr_at_init (struct darwin_info *info) info->all_image_addr += load_addr; } -/* Extract dyld_all_image_addr reading it from +/* Extract dyld_all_image_addr reading it from TARGET_OBJECT_DARWIN_DYLD_INFO. */ static void darwin_solib_read_all_image_info_addr (struct darwin_info *info) { - gdb_byte buf[8 + 8 + 4]; + gdb_byte buf[8]; LONGEST len; enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); + struct type *ptr_type = builtin_type (target_gdbarch ())->builtin_data_ptr; + + /* Sanity check. */ + if (ptr_type->length > sizeof (buf)) + return; len = target_read (¤t_target, TARGET_OBJECT_DARWIN_DYLD_INFO, NULL, - buf, 0, sizeof (buf)); - if (len != sizeof (buf)) + buf, 0, ptr_type->length); + if (len <= 0) return; - info->all_image_addr = extract_unsigned_integer (buf, 8, byte_order); + /* The use of BIG endian is intended, as BUF is a raw stream of bytes. This + makes the support of remote protocol easier. */ + info->all_image_addr = extract_unsigned_integer (buf, len, BFD_ENDIAN_BIG); } /* Shared library startup support. See documentation in solib-svr4.c. */ @@ -516,10 +567,25 @@ darwin_solib_create_inferior_hook (int from_tty) return; } + /* Add the breakpoint which is hit by dyld when the list of solib is + modified. */ create_solib_event_breakpoint (target_gdbarch (), info->all_image.notifier); - /* Possible relocate the main executable (PIE). */ - load_addr = darwin_read_exec_load_addr (info); + if (info->all_image.count != 0) + { + /* Possible relocate the main executable (PIE). */ + load_addr = darwin_read_exec_load_addr_from_dyld (info); + } + else + { + /* Possible issue: + Do not break on the notifier if dyld is not initialized (deduced from + count == 0). In that case, dyld hasn't relocated itself and the + notifier may point to a wrong address. */ + + load_addr = darwin_read_exec_load_addr_at_init (info); + } + if (load_addr != 0 && symfile_objfile != NULL) { CORE_ADDR vmaddr; |