diff options
Diffstat (limited to 'gdb/ppc-linux-tdep.c')
| -rw-r--r-- | gdb/ppc-linux-tdep.c | 73 |
1 files changed, 47 insertions, 26 deletions
diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c index bbe9e89..ed0ea13 100644 --- a/gdb/ppc-linux-tdep.c +++ b/gdb/ppc-linux-tdep.c @@ -256,8 +256,8 @@ ppc_linux_return_value (struct gdbarch *gdbarch, struct value *function, readbuf, writebuf); } -/* PLT stub in executable. */ -static struct ppc_insn_pattern powerpc32_plt_stub[] = +/* PLT stub in an executable. */ +static const struct ppc_insn_pattern powerpc32_plt_stub[] = { { 0xffff0000, 0x3d600000, 0 }, /* lis r11, xxxx */ { 0xffff0000, 0x816b0000, 0 }, /* lwz r11, xxxx(r11) */ @@ -266,16 +266,30 @@ static struct ppc_insn_pattern powerpc32_plt_stub[] = { 0, 0, 0 } }; -/* PLT stub in shared library. */ -static struct ppc_insn_pattern powerpc32_plt_stub_so[] = +/* PLT stubs in a shared library or PIE. + The first variant is used when the PLT entry is within +/-32k of + the GOT pointer (r30). */ +static const struct ppc_insn_pattern powerpc32_plt_stub_so_1[] = { { 0xffff0000, 0x817e0000, 0 }, /* lwz r11, xxxx(r30) */ { 0xffffffff, 0x7d6903a6, 0 }, /* mtctr r11 */ { 0xffffffff, 0x4e800420, 0 }, /* bctr */ - { 0xffffffff, 0x60000000, 0 }, /* nop */ { 0, 0, 0 } }; -#define POWERPC32_PLT_STUB_LEN ARRAY_SIZE (powerpc32_plt_stub) + +/* The second variant is used when the PLT entry is more than +/-32k + from the GOT pointer (r30). */ +static const struct ppc_insn_pattern powerpc32_plt_stub_so_2[] = + { + { 0xffff0000, 0x3d7e0000, 0 }, /* addis r11, r30, xxxx */ + { 0xffff0000, 0x816b0000, 0 }, /* lwz r11, xxxx(r11) */ + { 0xffffffff, 0x7d6903a6, 0 }, /* mtctr r11 */ + { 0xffffffff, 0x4e800420, 0 }, /* bctr */ + { 0, 0, 0 } + }; + +/* The max number of insns we check using ppc_insns_match_pattern. */ +#define POWERPC32_PLT_CHECK_LEN (ARRAY_SIZE (powerpc32_plt_stub) - 1) /* Check if PC is in PLT stub. For non-secure PLT, stub is in .plt section. For secure PLT, stub is in .text and we need to check @@ -306,13 +320,13 @@ powerpc_linux_in_dynsym_resolve_code (CORE_ADDR pc) When the execution direction is EXEC_REVERSE, scan backward to check whether we are in the middle of a PLT stub. Currently, - we only look-behind at most 4 instructions (the max length of PLT + we only look-behind at most 4 instructions (the max length of a PLT stub sequence. */ static CORE_ADDR ppc_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) { - unsigned int insnbuf[POWERPC32_PLT_STUB_LEN]; + unsigned int insnbuf[POWERPC32_PLT_CHECK_LEN]; struct gdbarch *gdbarch = get_frame_arch (frame); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); @@ -323,40 +337,47 @@ ppc_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) /* When reverse-debugging, scan backward to check whether we are in the middle of trampoline code. */ if (execution_direction == EXEC_REVERSE) - scan_limit = 4; /* At more 4 instructions. */ + scan_limit = 4; /* At most 4 instructions. */ for (i = 0; i < scan_limit; i++) { if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub, insnbuf)) { - /* Insn pattern is + /* Calculate PLT entry address from lis r11, xxxx - lwz r11, xxxx(r11) - Branch target is in r11. */ - - target = (ppc_insn_d_field (insnbuf[0]) << 16) - | ppc_insn_d_field (insnbuf[1]); - target = read_memory_unsigned_integer (target, 4, byte_order); + lwz r11, xxxx(r11). */ + target = ((ppc_insn_d_field (insnbuf[0]) << 16) + + ppc_insn_d_field (insnbuf[1])); + } + else if (i < ARRAY_SIZE (powerpc32_plt_stub_so_1) - 1 + && ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub_so_1, + insnbuf)) + { + /* Calculate PLT entry address from + lwz r11, xxxx(r30). */ + target = (ppc_insn_d_field (insnbuf[0]) + + get_frame_register_unsigned (frame, + tdep->ppc_gp0_regnum + 30)); } - else if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub_so, + else if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub_so_2, insnbuf)) { - /* Insn pattern is - lwz r11, xxxx(r30) - Branch target is in r11. */ - - target = get_frame_register_unsigned (frame, - tdep->ppc_gp0_regnum + 30) - + ppc_insn_d_field (insnbuf[0]); - target = read_memory_unsigned_integer (target, 4, byte_order); + /* Calculate PLT entry address from + addis r11, r30, xxxx + lwz r11, xxxx(r11). */ + target = ((ppc_insn_d_field (insnbuf[0]) << 16) + + ppc_insn_d_field (insnbuf[1]) + + get_frame_register_unsigned (frame, + tdep->ppc_gp0_regnum + 30)); } else { - /* Scan backward one more instructions if doesn't match. */ + /* Scan backward one more instruction if it doesn't match. */ pc -= 4; continue; } + target = read_memory_unsigned_integer (target, 4, byte_order); return target; } |