Author: cem Date: Wed Sep 30 14:55:54 2020 New Revision: 366291 URL: https://svnweb.freebsd.org/changeset/base/366291
Log: gdb(4): Don't escape GDB special characters at application layer In r351368, we introduced this XML- and GDB-encoded data. The protocol 'offset' should reflex the logical XML data offset, but unfortunately we counted the GDB escapes as well. In fact, we cannot safely do GDB character escaping at this layer at all, because we don't know what will be flushed in a packet. It is bogus to send only the first character of a two-character escape sequence. This patch "corrects" the problem by squashing these characters in the transmitted XML document. It would be nice to transmit the characters faithfully, but that is a more complicated change. Thread names are a nice convenience feature for the GDB client, but one can always inspect td_name or p_comm directly to find the true name. Reported by: Ka Ho Ng <khng300 AT gmail.com> Tested by: Ka Ho Ng Reviewed by: emaste, markj, rlibby Differential Revision: https://reviews.freebsd.org/D26599 Modified: head/sys/gdb/gdb_main.c Modified: head/sys/gdb/gdb_main.c ============================================================================== --- head/sys/gdb/gdb_main.c Wed Sep 30 13:33:28 2020 (r366290) +++ head/sys/gdb/gdb_main.c Wed Sep 30 14:55:54 2020 (r366291) @@ -361,9 +361,7 @@ init_qXfer_ctx(struct qXfer_context *qx, uintmax_t len } /* - * dst must be 2x strlen(max_src) + 1. - * - * Squashes invalid XML characters down to _. Sorry. Then escapes for GDB. + * Squashes special XML and GDB characters down to _. Sorry. */ static void qXfer_escape_xmlattr_str(char *dst, size_t dstlen, const char *src) @@ -384,8 +382,18 @@ qXfer_escape_xmlattr_str(char *dst, size_t dstlen, con /* GDB escape. */ if (strchr(forbidden, c) != NULL) { + /* + * It would be nice to escape these properly, but to do + * it correctly we need to escape them in the transmit + * layer, potentially doubling our buffer requirements. + * For now, avoid breaking the protocol by squashing + * them to underscore. + */ +#if 0 *dst++ = '}'; c ^= 0x20; +#endif + c = '_'; } *dst++ = c; } _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
