From cf90fd9a07e8998540bf74f293d348a6653ac120 Mon Sep 17 00:00:00 2001 From: Wei-cheng Wang Date: Sat, 17 Jan 2015 14:30:59 +0800 Subject: [PATCH] Skip-trampoline for PowerPC reverse-stepping. --- gdb/ChangeLog | 6 +++ gdb/ppc-linux-tdep.c | 58 +++++++++++++++++++---------- gdb/ppc64-tdep.c | 88 ++++++++++++++++++++++++++++++-------------- 3 files changed, 105 insertions(+), 47 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 6866edb954d..d4008e9c497 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2015-01-17 Wei-cheng Wang + + * ppc-linux-tdep.c (ppc_skip_trampoline_code): + Scan PLT stub backward for reverse debugging. + * ppc64-tdep.c (ppc64_skip_trampoline_code): Likewise. + 2015-01-17 Wei-cheng Wang Ulrich Weigand diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c index dcfd3bb9f97..13bb479fe3a 100644 --- a/gdb/ppc-linux-tdep.c +++ b/gdb/ppc-linux-tdep.c @@ -51,6 +51,7 @@ #include "linux-tdep.h" #include "linux-record.h" #include "record-full.h" +#include "infrun.h" #include "stap-probe.h" #include "ax.h" @@ -314,31 +315,50 @@ ppc_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); CORE_ADDR target = 0; + int scan_limit, i; - if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub, insnbuf)) - { - /* Insn pattern is - 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); - } + scan_limit = 1; + /* 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. */ - if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub_so, insnbuf)) + for (i = 0; i < scan_limit; i++) { - /* Insn pattern is - lwz r11, xxxx(r30) - Branch target is in r11. */ + if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub, insnbuf)) + { + /* Insn pattern is + 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); + } + else if (ppc_insns_match_pattern (frame, pc, powerpc32_plt_stub_so, + 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); + } + else + { + /* Scan backward one more instructions if doesn't match. */ + pc -= 4; + continue; + } - 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); + return target; } - return target; + return 0; } /* Wrappers to handle Linux-only registers. */ diff --git a/gdb/ppc64-tdep.c b/gdb/ppc64-tdep.c index 60ef86a1c6f..66d7b2362e1 100644 --- a/gdb/ppc64-tdep.c +++ b/gdb/ppc64-tdep.c @@ -20,6 +20,7 @@ #include "defs.h" #include "frame.h" #include "gdbcore.h" +#include "infrun.h" #include "ppc-tdep.h" #include "ppc64-tdep.h" #include "elf-bfd.h" @@ -464,35 +465,66 @@ ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) ARRAY_SIZE (ppc64_standard_linkage8)))) - 1]; CORE_ADDR target; + int scan_limit, i; - if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage8, insns)) - pc = ppc64_standard_linkage4_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage7, insns)) - pc = ppc64_standard_linkage3_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage6, insns)) - pc = ppc64_standard_linkage4_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage5, insns) - && (insns[8] != 0 || insns[9] != 0)) - pc = ppc64_standard_linkage3_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage4, insns) - && (insns[9] != 0 || insns[10] != 0)) - pc = ppc64_standard_linkage4_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage3, insns) - && (insns[8] != 0 || insns[9] != 0)) - pc = ppc64_standard_linkage3_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage2, insns) - && (insns[10] != 0 || insns[11] != 0)) - pc = ppc64_standard_linkage2_target (frame, pc, insns); - else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage1, insns)) - pc = ppc64_standard_linkage1_target (frame, pc, insns); - else - return 0; - - /* The PLT descriptor will either point to the already resolved target - address, or else to a glink stub. As the latter carry synthetic @plt - symbols, find_solib_trampoline_target should be able to resolve them. */ - target = find_solib_trampoline_target (frame, pc); - return target ? target : pc; + scan_limit = 1; + /* When reverse-debugging, scan backward to check whether we are + in the middle of trampoline code. */ + if (execution_direction == EXEC_REVERSE) + scan_limit = ARRAY_SIZE (insns) - 1; + + for (i = 0; i < scan_limit; i++) + { + if (i < ARRAY_SIZE (ppc64_standard_linkage8) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage8, insns)) + pc = ppc64_standard_linkage4_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage7) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage7, + insns)) + pc = ppc64_standard_linkage3_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage6) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage6, + insns)) + pc = ppc64_standard_linkage4_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage5) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage5, + insns) + && (insns[8] != 0 || insns[9] != 0)) + pc = ppc64_standard_linkage3_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage4) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage4, + insns) + && (insns[9] != 0 || insns[10] != 0)) + pc = ppc64_standard_linkage4_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage3) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage3, + insns) + && (insns[8] != 0 || insns[9] != 0)) + pc = ppc64_standard_linkage3_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage2) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage2, + insns) + && (insns[10] != 0 || insns[11] != 0)) + pc = ppc64_standard_linkage2_target (frame, pc, insns); + else if (i < ARRAY_SIZE (ppc64_standard_linkage1) - 1 + && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage1, + insns)) + pc = ppc64_standard_linkage1_target (frame, pc, insns); + else + { + /* Scan backward one more instructions if doesn't match. */ + pc -= 4; + continue; + } + + /* The PLT descriptor will either point to the already resolved target + address, or else to a glink stub. As the latter carry synthetic @plt + symbols, find_solib_trampoline_target should be able to resolve them. */ + target = find_solib_trampoline_target (frame, pc); + return target ? target : pc; + } + + return 0; } /* Support for convert_from_func_ptr_addr (ARCH, ADDR, TARG) on PPC64 -- 2.30.2