From f5396833d35a257902409493a63f777dcd771868 Mon Sep 17 00:00:00 2001 From: Andreas Arnez Date: Wed, 9 Nov 2016 13:02:13 +0100 Subject: [PATCH] tui-disasm: Fix line buffer size calculation The code that fills the TUI disassembly window content first calculates the maximum full length of a displayed disassembly line. This calculation typically yields the wrong result. The result is too large, so the bug does not cause any run-time failures, but unnecessary confusion for the reader. This patch fixes the calculation. gdb/ChangeLog: * tui/tui-disasm.c (tui_set_disassem_content): Fix calculation of the longest disassembly line's length. --- gdb/ChangeLog | 5 +++++ gdb/tui/tui-disasm.c | 19 ++++++++++--------- 2 files changed, 15 insertions(+), 9 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index b6bd2c1..ca17d84 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,10 @@ 2016-11-09 Andreas Arnez + * tui/tui-disasm.c (tui_set_disassem_content): Fix calculation of + the longest disassembly line's length. + +2016-11-09 Andreas Arnez + * tui/tui-disasm.c (tui_set_disassem_content): Fix line buffer overrun due to unchecked strcpy. diff --git a/gdb/tui/tui-disasm.c b/gdb/tui/tui-disasm.c index 5368aa4..6811be3 100644 --- a/gdb/tui/tui-disasm.c +++ b/gdb/tui/tui-disasm.c @@ -178,7 +178,7 @@ tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc) int tab_len = tui_default_tab_len (); struct tui_asm_line *asm_lines; int insn_pos; - int addr_size, max_size; + int addr_size, insn_size; char *line; if (pc == 0) @@ -203,9 +203,9 @@ tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc) tui_disassemble (gdbarch, asm_lines, pc, max_lines); - /* See what is the maximum length of an address and of a line. */ + /* Determine maximum address- and instruction lengths. */ addr_size = 0; - max_size = 0; + insn_size = 0; for (i = 0; i < max_lines; i++) { size_t len = strlen (asm_lines[i].addr_string); @@ -213,16 +213,17 @@ tui_set_disassem_content (struct gdbarch *gdbarch, CORE_ADDR pc) if (len > addr_size) addr_size = len; - len = strlen (asm_lines[i].insn) + tab_len; - if (len > max_size) - max_size = len; + len = strlen (asm_lines[i].insn); + if (len > insn_size) + insn_size = len; } - max_size += addr_size + tab_len; - /* Allocate memory to create each line. */ - line = (char*) alloca (max_size); + /* Align instructions to the same column. */ insn_pos = (1 + (addr_size / tab_len)) * tab_len; + /* Allocate memory to create each line. */ + line = (char*) alloca (insn_pos + insn_size + 1); + /* Now construct each line. */ for (i = 0; i < max_lines; i++) { -- 2.7.4