[PATCH] disass: Add /x modifier to print offsets in hex
fam@euphon.net
fam@euphon.net
Wed Sep 23 10:11:48 GMT 2020
From: Fam Zheng <famzheng@amazon.com>
Backtrace messages printed by Linux kernel and Xen have hex offsets,
e.g.:
(XEN) Xen call trace:
(XEN) [<ffff82d0402eefbb>] R guest_walk_tables_2_levels+0x189/0x66d
(XEN) [<ffff82d0402edbbd>] F hap_p2m_ga_to_gfn_2_levels+0x112/0x25b
(XEN) [<ffff82d0402edd22>] F hap_gva_to_gfn_2_levels+0x1c/0x1e
(XEN) [<ffff82d0402f832e>] F paging_gva_to_gfn+0x14a/0x167
Having this modifier saves converting between hex values from the
backtrace log and offsets in gdb disass output.
---
gdb/cli/cli-cmds.c | 19 +++++++++++++------
gdb/disasm.c | 6 +++++-
gdb/disasm.h | 1 +
gdb/record.c | 3 +++
4 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index e3965fea07..3083f84d05 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -5,7 +5,7 @@
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
+ it under the teHEX_OFFSET of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
@@ -1456,12 +1456,12 @@ disassemble_current_function (gdb_disassembly_flags flags)
/* Dump a specified section of assembly code.
Usage:
- disassemble [/mrs]
+ disassemble [/mrsx]
- dump the assembly code for the function of the current pc
- disassemble [/mrs] addr
+ disassemble [/mrsx] addr
- dump the assembly code for the function at ADDR
- disassemble [/mrs] low,high
- disassemble [/mrs] low,+length
+ disassemble [/mrsx] low,high
+ disassemble [/mrsx] low,+length
- dump the assembly code in the range [LOW,HIGH), or [LOW,LOW+length)
A /m modifier will include source code with the assembly in a
@@ -1472,6 +1472,8 @@ disassemble_current_function (gdb_disassembly_flags flags)
A /r modifier will include raw instructions in hex with the assembly.
+ A /x modifier will print offsets in hex.
+
A /s modifier will include source code with the assembly, like /m, with
two important differences:
1) The output is still in pc address order.
@@ -1510,6 +1512,9 @@ disassemble_command (const char *arg, int from_tty)
case 'r':
flags |= DISASSEMBLY_RAW_INSN;
break;
+ case 'x':
+ flags |= DISASSEMBLY_HEX_OFFSET;
+ break;
case 's':
flags |= DISASSEMBLY_SOURCE;
break;
@@ -2535,7 +2540,7 @@ can be shown using \"show listsize\"."));
c = add_com ("disassemble", class_vars, disassemble_command, _("\
Disassemble a specified section of memory.\n\
-Usage: disassemble[/m|/r|/s] START [, END]\n\
+Usage: disassemble[/m|/r|/s|/r] START [, END]\n\
Default is the function surrounding the pc of the selected frame.\n\
\n\
With a /s modifier, source lines are included (if available).\n\
@@ -2551,6 +2556,8 @@ in favor of /s.\n\
\n\
With a /r modifier, raw instructions in hex are included.\n\
\n\
+With a /x modifier, offsets are printed as hex.\n\
+\n\
With a single argument, the function surrounding that address is dumped.\n\
Two arguments (separated by a comma) are taken as a range of memory to dump,\n\
in the form of \"start,end\", or \"start,+length\".\n\
diff --git a/gdb/disasm.c b/gdb/disasm.c
index e45c840068..47936e54f1 100644
--- a/gdb/disasm.c
+++ b/gdb/disasm.c
@@ -201,6 +201,7 @@ gdb_pretty_print_disassembler::pretty_print_insn (const struct disasm_insn *insn
int size;
CORE_ADDR pc;
struct gdbarch *gdbarch = arch ();
+ char offset_buf[32];
{
ui_out_emit_tuple tuple_emitter (m_uiout, NULL);
@@ -250,7 +251,10 @@ gdb_pretty_print_disassembler::pretty_print_insn (const struct disasm_insn *insn
the offset takes the place of the "+" here. */
if (offset >= 0)
m_uiout->text ("+");
- m_uiout->field_signed ("offset", offset);
+ snprintf(offset_buf, sizeof(offset_buf),
+ flags & DISASSEMBLY_HEX_OFFSET ? "0x%x" : "%d",
+ offset);
+ m_uiout->field_string("offset", offset_buf);
m_uiout->text (">:\t");
}
else
diff --git a/gdb/disasm.h b/gdb/disasm.h
index b0f535eaa2..fb293650de 100644
--- a/gdb/disasm.h
+++ b/gdb/disasm.h
@@ -31,6 +31,7 @@ enum gdb_disassembly_flag
DISASSEMBLY_OMIT_PC = (0x1 << 4),
DISASSEMBLY_SOURCE = (0x1 << 5),
DISASSEMBLY_SPECULATIVE = (0x1 << 6),
+ DISASSEMBLY_HEX_OFFSET = (0x1 << 7),
};
DEF_ENUM_FLAGS_TYPE (enum gdb_disassembly_flag, gdb_disassembly_flags);
diff --git a/gdb/record.c b/gdb/record.c
index 759395d5bc..44591e8cf0 100644
--- a/gdb/record.c
+++ b/gdb/record.c
@@ -494,6 +494,9 @@ get_insn_history_modifiers (const char **arg)
case 'r':
modifiers |= DISASSEMBLY_RAW_INSN;
break;
+ case 'x':
+ modifiers |= DISASSEMBLY_HEX_OFFSET;
+ break;
case 'f':
modifiers |= DISASSEMBLY_OMIT_FNAME;
break;
--
2.25.1
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