From: Michael Snyder <msnyder@vmware.com>
To: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>
Subject: Re: [RFA] gdbserver support for qCRC: (compare-sections)
Date: Mon, 22 Mar 2010 17:59:00 -0000 [thread overview]
Message-ID: <4BA7AFFD.6050308@vmware.com> (raw)
In-Reply-To: <4BA40867.4090703@vmware.com>
[-- Attachment #1: Type: text/plain, Size: 456 bytes --]
Michael Snyder wrote:
> This patch adds support to gdbserver for the "qCRC:" request.
>
> This in turn supports the gdb "compare-sections" command, which
> basically lets you verify that the binary image on the target
> matches the executable that you're debugging.
>
> I borrowed code from gdb/remote.c, I assume that's OK.
Fixed a "fixme" comment, now will return "E01" if the request
tries to read memory that isn't there.
Revised patch attached.
[-- Attachment #2: qcrc32.txt --]
[-- Type: text/plain, Size: 2363 bytes --]
2010-03-19 Michael Snyder <msnyder@vmware.com>
* server.c (crc32): New function.
(handle_query): Add handling for 'qCRC:' request.
Index: server.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/server.c,v
retrieving revision 1.108
diff -u -p -r1.108 server.c
--- server.c 20 Jan 2010 22:55:38 -0000 1.108
+++ server.c 22 Mar 2010 17:57:32 -0000
@@ -788,6 +788,47 @@ handle_threads_qxfer (const char *annex,
}
+/* Table used by the crc32 function to calcuate the checksum. */
+
+static unsigned long crc32_table[256] =
+{0, 0};
+
+/* Compute 32 bit CRC from inferior memory.
+
+ On success, return 32 bit CRC.
+ On failure, return (unsigned long long) -1. */
+
+static unsigned long long
+crc32 (CORE_ADDR base, int len, unsigned int crc)
+{
+ if (!crc32_table[1])
+ {
+ /* Initialize the CRC table and the decoding table. */
+ int i, j;
+ unsigned int c;
+
+ for (i = 0; i < 256; i++)
+ {
+ for (c = i << 24, j = 8; j > 0; --j)
+ c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1);
+ crc32_table[i] = c;
+ }
+ }
+
+ while (len--)
+ {
+ unsigned char byte = 0;
+
+ /* Return failure if memory read fails. */
+ if (read_inferior_memory (base, &byte, 1) != 0)
+ return (unsigned long long) -1;
+
+ crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ byte) & 255];
+ base++;
+ }
+ return (unsigned long long) crc;
+}
+
/* Handle all of the extended 'q' packets. */
void
handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
@@ -1421,6 +1462,31 @@ handle_query (char *own_buf, int packet_
return;
}
+ if (strncmp ("qCRC:", own_buf, 5) == 0)
+ {
+ /* CRC check (compare-segment). */
+ char *comma;
+ CORE_ADDR base = strtoul (own_buf + 5, &comma, 16);
+ int len;
+ unsigned long long crc;
+
+ if (*comma++ != ',')
+ {
+ write_enn (own_buf);
+ return;
+ }
+ len = strtoul (comma, NULL, 16);
+ crc = crc32 (base, len, 0xffffffff);
+ /* Check for memory failure. */
+ if (crc == (unsigned long long) -1)
+ {
+ write_enn (own_buf);
+ return;
+ }
+ sprintf (own_buf, "C%lx", (unsigned long) crc);
+ return;
+ }
+
/* Otherwise we didn't know what packet it was. Say we didn't
understand it. */
own_buf[0] = 0;
next prev parent reply other threads:[~2010-03-22 17:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-19 23:27 Michael Snyder
2010-03-22 17:59 ` Michael Snyder [this message]
2010-03-23 16:26 ` Pedro Alves
2010-03-23 18:16 ` Michael Snyder
2010-03-23 18:32 ` Pedro Alves
2010-03-23 22:44 ` Michael Snyder
2010-03-23 23:15 ` Pedro Alves
2010-03-24 0:16 ` Pedro Alves
2010-03-24 0:34 ` Michael Snyder
2010-03-24 1:15 ` Pedro Alves
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