From 7fcdec025c0510741f3d7efc53e623e03c29e7d3 Mon Sep 17 00:00:00 2001 From: Thiago Jung Bauermann Date: Sun, 1 Sep 2024 14:56:10 -0300 Subject: [PATCH] GDB: Use gdb::array_view for buffers used in register reading and unwinding This allows checking the size of the given buffer. Changes frame_register_unwind (), frame_unwind_register (), get_frame_register () and deprecated_frame_register_read (). As pointed out by Baris, in the case of MIPS target code this is best done by changing a couple of alloca-based buffers in mips_read_fp_register_single and mips_print_fp_register to gdb::byte_vector instances. Approved-By: Simon Marchi --- gdb/amd64-windows-tdep.c | 4 ++-- gdb/frame.c | 25 ++++++++++++--------- gdb/frame.h | 10 ++++----- gdb/mips-tdep.c | 48 ++++++++++++++++++++++------------------ 4 files changed, 48 insertions(+), 39 deletions(-) diff --git a/gdb/amd64-windows-tdep.c b/gdb/amd64-windows-tdep.c index 9e255bb2d43..ca7b7d96bc2 100644 --- a/gdb/amd64-windows-tdep.c +++ b/gdb/amd64-windows-tdep.c @@ -801,7 +801,7 @@ amd64_windows_frame_decode_insns (const frame_info_ptr &this_frame, std::array buf; int frreg = amd64_windows_w2gdb_regnum[frame_reg]; - get_frame_register (this_frame, frreg, buf.data ()); + get_frame_register (this_frame, frreg, buf); save_addr = extract_unsigned_integer (buf, byte_order); frame_debug_printf (" frame_reg=%s, val=%s", @@ -1097,7 +1097,7 @@ amd64_windows_frame_cache (const frame_info_ptr &this_frame, void **this_cache) /* Get current PC and SP. */ pc = get_frame_pc (this_frame); - get_frame_register (this_frame, AMD64_RSP_REGNUM, buf.data ()); + get_frame_register (this_frame, AMD64_RSP_REGNUM, buf); cache->sp = extract_unsigned_integer (buf, byte_order); cache->pc = pc; diff --git a/gdb/frame.c b/gdb/frame.c index ba4a07179f6..10a32dcd896 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -1112,7 +1112,7 @@ frame_save_as_regcache (const frame_info_ptr &this_frame) { auto cooked_read = [this_frame] (int regnum, gdb::array_view buf) { - if (!deprecated_frame_register_read (this_frame, regnum, buf.data ())) + if (!deprecated_frame_register_read (this_frame, regnum, buf)) return REG_UNAVAILABLE; else return REG_VALID; @@ -1177,17 +1177,17 @@ void frame_register_unwind (const frame_info_ptr &next_frame, int regnum, int *optimizedp, int *unavailablep, enum lval_type *lvalp, CORE_ADDR *addrp, - int *realnump, gdb_byte *bufferp) + int *realnump, + gdb::array_view buffer) { struct value *value; - /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates + /* Require all but BUFFER to be valid. An empty BUFFER indicates that the value proper does not need to be fetched. */ gdb_assert (optimizedp != NULL); gdb_assert (lvalp != NULL); gdb_assert (addrp != NULL); gdb_assert (realnump != NULL); - /* gdb_assert (bufferp != NULL); */ value = frame_unwind_register_value (next_frame, regnum); @@ -1202,13 +1202,15 @@ frame_register_unwind (const frame_info_ptr &next_frame, int regnum, else *realnump = -1; - if (bufferp) + if (!buffer.empty ()) { + gdb_assert (buffer.size () >= value->type ()->length ()); + if (!*optimizedp && !*unavailablep) - memcpy (bufferp, value->contents_all ().data (), + memcpy (buffer.data (), value->contents_all ().data (), value->type ()->length ()); else - memset (bufferp, 0, value->type ()->length ()); + memset (buffer.data (), 0, value->type ()->length ()); } /* Dispose of the new value. This prevents watchpoints from @@ -1217,7 +1219,8 @@ frame_register_unwind (const frame_info_ptr &next_frame, int regnum, } void -frame_unwind_register (const frame_info_ptr &next_frame, int regnum, gdb_byte *buf) +frame_unwind_register (const frame_info_ptr &next_frame, int regnum, + gdb::array_view buf) { int optimized; int unavailable; @@ -1238,7 +1241,7 @@ frame_unwind_register (const frame_info_ptr &next_frame, int regnum, gdb_byte *b void get_frame_register (const frame_info_ptr &frame, - int regnum, gdb_byte *buf) + int regnum, gdb::array_view buf) { frame_unwind_register (frame_info_ptr (frame->next), regnum, buf); } @@ -1482,7 +1485,7 @@ put_frame_register (const frame_info_ptr &next_frame, int regnum, bool deprecated_frame_register_read (const frame_info_ptr &frame, int regnum, - gdb_byte *myaddr) + gdb::array_view myaddr) { int optimized; int unavailable; @@ -1541,7 +1544,7 @@ get_frame_register_bytes (const frame_info_ptr &next_frame, int regnum, int realnum; frame_register_unwind (next_frame, regnum, optimizedp, unavailablep, - &lval, &addr, &realnum, buffer.data ()); + &lval, &addr, &realnum, buffer); if (*optimizedp || *unavailablep) return false; } diff --git a/gdb/frame.h b/gdb/frame.h index b265c9bc5bb..e207c714c56 100644 --- a/gdb/frame.h +++ b/gdb/frame.h @@ -685,14 +685,14 @@ const char *unwind_stop_reason_to_string (enum unwind_stop_reason); const char *frame_stop_reason_string (const frame_info_ptr &); /* Unwind the stack frame so that the value of REGNUM, in the previous - (up, older) frame is returned. If VALUEP is nullptr, don't + (up, older) frame is returned. If VALUE is zero-sized, don't fetch/compute the value. Instead just return the location of the value. */ extern void frame_register_unwind (const frame_info_ptr &frame, int regnum, int *optimizedp, int *unavailablep, enum lval_type *lvalp, CORE_ADDR *addrp, int *realnump, - gdb_byte *valuep = nullptr); + gdb::array_view value = {}); /* Fetch a register from this, or unwind a register from the next frame. Note that the get_frame methods are wrappers to @@ -701,9 +701,9 @@ extern void frame_register_unwind (const frame_info_ptr &frame, int regnum, do return a lazy value. */ extern void frame_unwind_register (const frame_info_ptr &next_frame, - int regnum, gdb_byte *buf); + int regnum, gdb::array_view buf); extern void get_frame_register (const frame_info_ptr &frame, - int regnum, gdb_byte *buf); + int regnum, gdb::array_view buf); struct value *frame_unwind_register_value (const frame_info_ptr &next_frame, int regnum); @@ -889,7 +889,7 @@ extern void print_frame_info (const frame_print_options &fp_opts, extern frame_info_ptr block_innermost_frame (const struct block *); extern bool deprecated_frame_register_read (const frame_info_ptr &frame, int regnum, - gdb_byte *buf); + gdb::array_view buf); /* From stack.c. */ diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c index c00efbd02ad..d217f23631f 100644 --- a/gdb/mips-tdep.c +++ b/gdb/mips-tdep.c @@ -951,14 +951,17 @@ mips_register_to_value (const frame_info_ptr &frame, int regnum, if (mips_convert_register_float_case_p (gdbarch, regnum, type)) { - get_frame_register (frame, regnum + 0, to + 4); - get_frame_register (frame, regnum + 1, to + 0); + gdb::array_view first_half = gdb::make_array_view (to, 4); + gdb::array_view second_half = gdb::make_array_view (to + 4, 4); - if (!get_frame_register_bytes (next_frame, regnum + 0, 0, { to + 4, 4 }, + get_frame_register (frame, regnum + 0, second_half); + get_frame_register (frame, regnum + 1, first_half); + + if (!get_frame_register_bytes (next_frame, regnum + 0, 0, second_half, optimizedp, unavailablep)) return 0; - if (!get_frame_register_bytes (next_frame, regnum + 1, 0, { to + 0, 4 }, + if (!get_frame_register_bytes (next_frame, regnum + 1, 0, first_half, optimizedp, unavailablep)) return 0; *optimizedp = *unavailablep = 0; @@ -6252,11 +6255,11 @@ mips_o64_return_value (struct gdbarch *gdbarch, struct value *function, static void mips_read_fp_register_single (const frame_info_ptr &frame, int regno, - gdb_byte *rare_buffer) + gdb::array_view rare_buffer) { struct gdbarch *gdbarch = get_frame_arch (frame); int raw_size = register_size (gdbarch, regno); - gdb_byte *raw_buffer = (gdb_byte *) alloca (raw_size); + gdb::byte_vector raw_buffer (raw_size); if (!deprecated_frame_register_read (frame, regno, raw_buffer)) error (_("can't read register %d (%s)"), @@ -6272,11 +6275,11 @@ mips_read_fp_register_single (const frame_info_ptr &frame, int regno, else offset = 0; - memcpy (rare_buffer, raw_buffer + offset, 4); + memcpy (rare_buffer.data (), raw_buffer.data () + offset, 4); } else { - memcpy (rare_buffer, raw_buffer, 4); + memcpy (rare_buffer.data (), raw_buffer.data (), 4); } } @@ -6286,7 +6289,7 @@ mips_read_fp_register_single (const frame_info_ptr &frame, int regno, static void mips_read_fp_register_double (const frame_info_ptr &frame, int regno, - gdb_byte *rare_buffer) + gdb::array_view rare_buffer) { struct gdbarch *gdbarch = get_frame_arch (frame); int raw_size = register_size (gdbarch, regno); @@ -6311,13 +6314,14 @@ mips_read_fp_register_double (const frame_info_ptr &frame, int regno, each register. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) { - mips_read_fp_register_single (frame, regno, rare_buffer + 4); + mips_read_fp_register_single (frame, regno, rare_buffer.slice (4)); mips_read_fp_register_single (frame, regno + 1, rare_buffer); } else { mips_read_fp_register_single (frame, regno, rare_buffer); - mips_read_fp_register_single (frame, regno + 1, rare_buffer + 4); + mips_read_fp_register_single (frame, regno + 1, + rare_buffer.slice (4)); } } } @@ -6327,15 +6331,13 @@ mips_print_fp_register (struct ui_file *file, const frame_info_ptr &frame, int regnum) { /* Do values for FP (float) regs. */ struct gdbarch *gdbarch = get_frame_arch (frame); - gdb_byte *raw_buffer; std::string flt_str, dbl_str; const struct type *flt_type = builtin_type (gdbarch)->builtin_float; const struct type *dbl_type = builtin_type (gdbarch)->builtin_double; - raw_buffer - = ((gdb_byte *) - alloca (2 * register_size (gdbarch, mips_regnum (gdbarch)->fp0))); + gdb::byte_vector raw_buffer (2 * register_size (gdbarch, + mips_regnum (gdbarch)->fp0)); gdb_printf (file, "%s:", gdbarch_register_name (gdbarch, regnum)); gdb_printf (file, "%*s", @@ -6349,10 +6351,11 @@ mips_print_fp_register (struct ui_file *file, const frame_info_ptr &frame, /* 4-byte registers: Print hex and floating. Also print even numbered registers as doubles. */ mips_read_fp_register_single (frame, regnum, raw_buffer); - flt_str = target_float_to_string (raw_buffer, flt_type, "%-17.9g"); + flt_str = target_float_to_string (raw_buffer.data (), flt_type, + "%-17.9g"); get_formatted_print_options (&opts, 'x'); - print_scalar_formatted (raw_buffer, + print_scalar_formatted (raw_buffer.data (), builtin_type (gdbarch)->builtin_uint32, &opts, 'w', file); @@ -6361,7 +6364,8 @@ mips_print_fp_register (struct ui_file *file, const frame_info_ptr &frame, if ((regnum - gdbarch_num_regs (gdbarch)) % 2 == 0) { mips_read_fp_register_double (frame, regnum, raw_buffer); - dbl_str = target_float_to_string (raw_buffer, dbl_type, "%-24.17g"); + dbl_str = target_float_to_string (raw_buffer.data (), dbl_type, + "%-24.17g"); gdb_printf (file, " dbl: %s", dbl_str.c_str ()); } @@ -6372,13 +6376,15 @@ mips_print_fp_register (struct ui_file *file, const frame_info_ptr &frame, /* Eight byte registers: print each one as hex, float and double. */ mips_read_fp_register_single (frame, regnum, raw_buffer); - flt_str = target_float_to_string (raw_buffer, flt_type, "%-17.9g"); + flt_str = target_float_to_string (raw_buffer.data (), flt_type, + "%-17.9g"); mips_read_fp_register_double (frame, regnum, raw_buffer); - dbl_str = target_float_to_string (raw_buffer, dbl_type, "%-24.17g"); + dbl_str = target_float_to_string (raw_buffer.data (), dbl_type, + "%-24.17g"); get_formatted_print_options (&opts, 'x'); - print_scalar_formatted (raw_buffer, + print_scalar_formatted (raw_buffer.data (), builtin_type (gdbarch)->builtin_uint64, &opts, 'g', file); -- 2.39.5