From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15126 invoked by alias); 9 Nov 2006 20:36:41 -0000 Received: (qmail 15116 invoked by uid 22791); 9 Nov 2006 20:36:40 -0000 X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (65.74.133.4) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 09 Nov 2006 20:36:36 +0000 Received: (qmail 3493 invoked from network); 9 Nov 2006 20:36:34 -0000 Received: from unknown (HELO ?172.16.64.38?) (vladimir@127.0.0.2) by mail.codesourcery.com with ESMTPA; 9 Nov 2006 20:36:34 -0000 From: Vladimir Prus To: gdb-patches@sources.redhat.com Subject: Check memory accesses Date: Thu, 09 Nov 2006 20:36:00 -0000 User-Agent: KMail/1.9.1 MIME-Version: 1.0 Content-Type: Multipart/Mixed; boundary="Boundary-00=_GF5UF1JkjHV7GZj" Message-Id: <200611092336.22512.vladimir@codesourcery.com> Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-11/txt/msg00054.txt.bz2 --Boundary-00=_GF5UF1JkjHV7GZj Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Content-length: 979 This patch makes gdb, when target memory map is available, optionally reject all memory accesses outside of regions in memory map. The rationale is that: 1. It's sometimes better to get error that have the write silently do nothing or read returning garbase. 2. For some targets, accesses to non-existent memory "wedge" them. Since memory maps are still rare, this behaviour is enabled only by a new command. OK? - Volodya * memattr.h (enum mem_access_mode): New value MEM_NONE. * memattr.c (unknown_mem_attrib): New. (inaccessible_by_default): New. (show_inaccessible_by_default): New. (lookup_mem_region): Check inaccessible_by_default. (dummy_cmd): New. (mem_set_cmdlist, mem_show_cmdlist): New. (_initialize_mem): Register new "set" and "show" commands. * target.c (memory_xfer_partial): If memory type is MEM_NONE, return an error. Clip to region size when calling to_xfer_partial. If upper limit of memory range is 0, don't clip anything. --Boundary-00=_GF5UF1JkjHV7GZj Content-Type: text/x-diff; charset="us-ascii"; name="memcheck.diff" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="memcheck.diff" Content-length: 5815 Index: memattr.c =================================================================== RCS file: /cvs/src/src/gdb/memattr.c,v retrieving revision 1.25 diff -u -r1.25 memattr.c --- memattr.c 21 Sep 2006 14:00:53 -0000 1.25 +++ memattr.c 9 Nov 2006 20:28:25 -0000 @@ -29,6 +29,7 @@ #include "language.h" #include "vec.h" #include "gdb_string.h" +#include "gdb_locale.h" const struct mem_attrib default_mem_attrib = { @@ -40,6 +41,16 @@ -1 /* Flash blocksize not specified. */ }; +const struct mem_attrib unknown_mem_attrib = +{ + MEM_NONE, /* mode */ + MEM_WIDTH_UNSPECIFIED, + 0, /* hwbreak */ + 0, /* cache */ + 0, /* verify */ + -1 /* Flash blocksize not specified. */ +}; + VEC(mem_region_s) *mem_region_list, *target_mem_region_list; static int mem_number = 0; @@ -53,6 +64,25 @@ empty, then the target can't supply memory regions. */ static int target_mem_regions_valid; +/* If this flag is set, gdb will assume that memory ranges not + specified by the memory map have type MEM_NONE, and will + emit errors on all accesses to that memory. */ +static int inaccessible_by_default = 0; + +static void +show_inaccessible_by_default (struct ui_file *file, int from_tty, + struct cmd_list_element *c, + const char *value) +{ + if (inaccessible_by_default) + fprintf_filtered (file, _("\ +Unknown memory addresses will be treated as inaccessible.\n")); + else + fprintf_filtered (file, _("\ +Unknown memory addresses will be treated as RAM.\n")); +} + + /* Predicate function which returns true if LHS should sort before RHS in a list of memory regions, useful for VEC_lower_bound. */ @@ -215,13 +245,17 @@ lo = 0; hi = 0; - /* If we ever want to support a huge list of memory regions, this + /* Either find memory range containing ADDRESS, or set LO and HI + to the nearest boundaries of an existing memory range. + + If we ever want to support a huge list of memory regions, this check should be replaced with a binary search (probably using VEC_lower_bound). */ for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++) { if (m->enabled_p == 1) { + /* If address is in memory return, return that memory range. */ if (addr >= m->lo && (addr < m->hi || m->hi == 0)) return m; @@ -243,7 +277,15 @@ was learned above. */ region.lo = lo; region.hi = hi; - region.attrib = default_mem_attrib; + + /* When no memory map is defined at all, we always set 'default_mem_attrib', + so that we do not make the all memory inaccessible for targets that don't + provide a memory map. */ + if (inaccessible_by_default && !VEC_empty (mem_region_s, mem_region_list)) + region.attrib = unknown_mem_attrib; + else + region.attrib = default_mem_attrib; + return ®ion; } @@ -674,9 +716,17 @@ dont_repeat (); } + +static void +dummy_cmd (char *args, int from_tty) +{ +} extern initialize_file_ftype _initialize_mem; /* -Wmissing-prototype */ +static struct cmd_list_element *mem_set_cmdlist; +static struct cmd_list_element *mem_show_cmdlist; + void _initialize_mem (void) { @@ -709,4 +759,25 @@ add_info ("mem", mem_info_command, _("Memory region attributes")); + + add_prefix_cmd ("mem", class_vars, dummy_cmd, _("\ +Memory regions settings"), + &mem_set_cmdlist, "set mem ", + 0/* allow-unknown */, &setlist); + add_prefix_cmd ("mem", class_vars, dummy_cmd, _("\ +Memory regions settings"), + &mem_show_cmdlist, "show mem ", + 0/* allow-unknown */, &showlist); + + add_setshow_boolean_cmd ("inaccessible-by-default", no_class, + &inaccessible_by_default, _("\ +Set handling of unknown memory regions."), _("\ +Show handling of unknown memory regions."), _("\ +If on, and some memory map is defined, debugger will emit errors on\n\ +accesses to memory not defined in the memory map. If off, accesses to all\n\ +memory addresses will be allowed."), + NULL, + show_inaccessible_by_default, + &mem_set_cmdlist, + &mem_show_cmdlist); } Index: memattr.h =================================================================== RCS file: /cvs/src/src/gdb/memattr.h,v retrieving revision 1.7 diff -u -r1.7 memattr.h --- memattr.h 21 Sep 2006 13:54:02 -0000 1.7 +++ memattr.h 9 Nov 2006 20:28:25 -0000 @@ -26,6 +26,7 @@ enum mem_access_mode { + MEM_NONE, /* Memory that is not physically present. */ MEM_RW, /* read/write */ MEM_RO, /* read only */ MEM_WO, /* write only */ @@ -76,7 +77,10 @@ struct mem_region { + /* Lowest address in the region. */ CORE_ADDR lo; + /* Address past the highest address of the region. + If 0, upper bound is "infinity". */ CORE_ADDR hi; /* Item number of this memory region. */ Index: target.c =================================================================== RCS file: /cvs/src/src/gdb/target.c,v retrieving revision 1.128 diff -u -r1.128 target.c --- target.c 17 Oct 2006 21:55:23 -0000 1.128 +++ target.c 9 Nov 2006 20:28:26 -0000 @@ -1015,7 +1015,8 @@ /* Try GDB's internal data cache. */ region = lookup_mem_region (memaddr); - if (memaddr + len < region->hi) + /* region->hi means there's no upper bound. */ + if (memaddr + len < region->hi || region->hi == 0) reg_len = len; else reg_len = region->hi - memaddr; @@ -1037,6 +1038,9 @@ if (writebuf != NULL) error (_("Writing to flash memory forbidden in this context")); break; + + case MEM_NONE: + return -1; } if (region->attrib.cache) @@ -1072,7 +1076,7 @@ do { res = ops->to_xfer_partial (ops, TARGET_OBJECT_MEMORY, NULL, - readbuf, writebuf, memaddr, len); + readbuf, writebuf, memaddr, reg_len); if (res > 0) return res; --Boundary-00=_GF5UF1JkjHV7GZj--