diff options
Diffstat (limited to 'gdb/gdbserver/ax.c')
| -rw-r--r-- | gdb/gdbserver/ax.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/gdb/gdbserver/ax.c b/gdb/gdbserver/ax.c index 4075c26..70e9322 100644 --- a/gdb/gdbserver/ax.c +++ b/gdb/gdbserver/ax.c @@ -18,6 +18,7 @@ #include "server.h" #include "ax.h" +#include "format.h" static void ax_vdebug (const char *, ...) ATTR_FORMAT (printf, 1, 2); @@ -789,6 +790,123 @@ compile_bytecodes (struct agent_expr *aexpr) #endif +/* Make printf-type calls using arguments supplied from the host. We + need to parse the format string ourselves, and call the formatting + function with one argument at a time, partly because there is no + safe portable way to construct a varargs call, and partly to serve + as a security barrier against bad format strings that might get + in. */ + +static void +ax_printf (CORE_ADDR fn, CORE_ADDR chan, char *format, + int nargs, ULONGEST *args) +{ + char *f = format; + struct format_piece *fpieces; + int i, fp; + char *current_substring; + int nargs_wanted; + + ax_debug ("Printf of \"%s\" with %d args", format, nargs); + + fpieces = parse_format_string (&f); + + nargs_wanted = 0; + for (fp = 0; fpieces[fp].string != NULL; fp++) + if (fpieces[fp].argclass != literal_piece) + ++nargs_wanted; + + if (nargs != nargs_wanted) + error (_("Wrong number of arguments for specified format-string")); + + i = 0; + for (fp = 0; fpieces[fp].string != NULL; fp++) + { + current_substring = fpieces[fp].string; + ax_debug ("current substring is '%s', class is %d", + current_substring, fpieces[fp].argclass); + switch (fpieces[fp].argclass) + { + case string_arg: + { + gdb_byte *str; + CORE_ADDR tem; + int j; + + tem = args[i]; + + /* This is a %s argument. Find the length of the string. */ + for (j = 0;; j++) + { + gdb_byte c; + + read_inferior_memory (tem + j, &c, 1); + if (c == 0) + break; + } + + /* Copy the string contents into a string inside GDB. */ + str = (gdb_byte *) alloca (j + 1); + if (j != 0) + read_inferior_memory (tem, str, j); + str[j] = 0; + + printf (current_substring, (char *) str); + } + break; + + case long_long_arg: +#if defined (CC_HAS_LONG_LONG) && defined (PRINTF_HAS_LONG_LONG) + { + long long val = args[i]; + + printf (current_substring, val); + break; + } +#else + error (_("long long not supported in agent printf")); +#endif + case int_arg: + { + int val = args[i]; + + printf (current_substring, val); + break; + } + + case long_arg: + { + long val = args[i]; + + printf (current_substring, val); + break; + } + + case literal_piece: + /* Print a portion of the format string that has no + directives. Note that this will not include any + ordinary %-specs, but it might include "%%". That is + why we use printf_filtered and not puts_filtered here. + Also, we pass a dummy argument because some platforms + have modified GCC to include -Wformat-security by + default, which will warn here if there is no + argument. */ + printf (current_substring, 0); + break; + + default: + error (_("Format directive in '%s' not supported in agent printf"), + current_substring); + } + + /* Maybe advance to the next argument. */ + if (fpieces[fp].argclass != literal_piece) + ++i; + } + + free_format_pieces (fpieces); +} + /* The agent expression evaluator, as specified by the GDB docs. It returns 0 if everything went OK, and a nonzero error code otherwise. */ @@ -1152,6 +1270,43 @@ gdb_eval_agent_expr (struct regcache *regcache, top = stack[sp]; break; + case gdb_agent_op_printf: + { + int nargs, slen, i; + CORE_ADDR fn = 0, chan = 0; + /* Can't have more args than the entire size of the stack. */ + ULONGEST args[STACK_MAX]; + char *format; + + nargs = aexpr->bytes[pc++]; + slen = aexpr->bytes[pc++]; + slen = (slen << 8) + aexpr->bytes[pc++]; + format = (char *) &(aexpr->bytes[pc]); + pc += slen; + /* Pop function and channel. */ + fn = top; + if (--sp >= 0) + top = stack[sp]; + chan = top; + if (--sp >= 0) + top = stack[sp]; + /* Pop arguments into a dedicated array. */ + for (i = 0; i < nargs; ++i) + { + args[i] = top; + if (--sp >= 0) + top = stack[sp]; + } + + /* A bad format string means something is very wrong; give + up immediately. */ + if (format[slen - 1] != '\0') + error (_("Unterminated format string in printf bytecode")); + + ax_printf (fn, chan, format, nargs, args); + } + break; + /* GDB never (currently) generates any of these ops. */ case gdb_agent_op_float: case gdb_agent_op_ref_float: |