From 94355de7751579b0182bd5821a3223939054f5d7 Mon Sep 17 00:00:00 2001 From: Luis Machado Date: Mon, 31 Oct 2022 13:26:20 +0000 Subject: [PATCH] [gdb/aarch64] Use safer memory read routines PR tdep/28796 As reported, we are using some memory read routines that don't handle read errors gracefully. Convert those to use the safe_* versions if available. This allows the code to handle those read errors in a more sensible way. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28796 --- gdb/aarch64-tdep.c | 42 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-) diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index d9ddc84a140..07330356fdc 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -2940,8 +2940,18 @@ aarch64_software_single_step (struct regcache *regcache) CORE_ADDR breaks[2] = { CORE_ADDR_MAX, CORE_ADDR_MAX }; CORE_ADDR loc = pc; CORE_ADDR closing_insn = 0; - uint32_t insn = read_memory_unsigned_integer (loc, insn_size, - byte_order_for_code); + + ULONGEST insn_from_memory; + if (!safe_read_memory_unsigned_integer (loc, insn_size, + byte_order_for_code, + &insn_from_memory)) + { + /* Assume we don't have a atomic sequence, as we couldn't read the + instruction in this location. */ + return {}; + } + + uint32_t insn = insn_from_memory; int index; int insn_count; int bc_insn_count = 0; /* Conditional branch instruction count. */ @@ -2958,9 +2968,17 @@ aarch64_software_single_step (struct regcache *regcache) for (insn_count = 0; insn_count < atomic_sequence_length; ++insn_count) { loc += insn_size; - insn = read_memory_unsigned_integer (loc, insn_size, - byte_order_for_code); + if (!safe_read_memory_unsigned_integer (loc, insn_size, + byte_order_for_code, + &insn_from_memory)) + { + /* Assume we don't have a atomic sequence, as we couldn't read the + instruction in this location. */ + return {}; + } + + insn = insn_from_memory; if (aarch64_decode_insn (insn, &inst, 1, NULL) != 0) return {}; /* Check if the instruction is a conditional branch. */ @@ -3259,9 +3277,15 @@ aarch64_displaced_step_copy_insn (struct gdbarch *gdbarch, struct regcache *regs) { enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); - uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order_for_code); struct aarch64_displaced_step_data dsd; aarch64_inst inst; + ULONGEST insn_from_memory; + + if (!safe_read_memory_unsigned_integer (from, 4, byte_order_for_code, + &insn_from_memory)) + return nullptr; + + uint32_t insn = insn_from_memory; if (aarch64_decode_insn (insn, &inst, 1, NULL) != 0) return NULL; @@ -3472,7 +3496,13 @@ aarch64_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc) return 0; enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); - uint32_t insn = read_memory_unsigned_integer (pc, 4, byte_order_for_code); + + ULONGEST insn_from_memory; + if (!safe_read_memory_unsigned_integer (pc, 4, byte_order_for_code, + &insn_from_memory)) + return 0; + + uint32_t insn = insn_from_memory; aarch64_inst inst; if (aarch64_decode_insn (insn, &inst, 1, nullptr) != 0) -- 2.30.2