From f1f0a06d5b34231edd75fbd71a3be79097437f62 Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Tue, 26 Sep 2023 17:32:24 +0100 Subject: [PATCH] gdbserver: fix handling of single quote arguments I noticed that passing arguments containing single quotes to gdbserver didn't work correctly: gdb -ex 'set sysroot' --args /tmp/show-args Reading symbols from /tmp/show-args... (gdb) target extended-remote | gdbserver --once --multi - /tmp/show-args Remote debugging using | gdbserver --once --multi - /tmp/show-args stdin/stdout redirected Process /tmp/show-args created; pid = 176054 Remote debugging using stdio Reading symbols from /lib64/ld-linux-x86-64.so.2... (No debugging symbols found in /lib64/ld-linux-x86-64.so.2) 0x00007ffff7fd3110 in _start () from /lib64/ld-linux-x86-64.so.2 (gdb) set args \' (gdb) r The program being debugged has been started already. Start it from the beginning? (y or n) y Starting program: /tmp/show-args \' stdin/stdout redirected Process /tmp/show-args created; pid = 176088 2 args are: /tmp/show-args \' Done. [Inferior 1 (process 176088) exited normally] (gdb) target native Done. Use the "run" command to start a process. (gdb) run Starting program: /tmp/show-args \' 2 args are: /tmp/show-args ' Done. [Inferior 1 (process 176095) exited normally] (gdb) q The 'shows-args' program used here just prints the arguments passed to the inferior. Notice that when starting the inferior using the extended-remote target the second argument is "\'", while when running using native target the argument is "'". The second of these is correct, the \' used with the "set args" command is just to show GDB that the single quote is not opening an argument string. It turns out that the extra backslash is injected on the gdbserver side when gdbserver processes the arguments that GDB passes it, the code that does this was added as part of this much larger commit: commit 2090129c36c7e582943b7d300968d19b46160d84 Date: Thu Dec 22 21:11:11 2016 -0500 Share fork_inferior et al with gdbserver In this commit I propose removing the specific code that adds what I believe is a stray backslash. I've extended an existing test to cover this case, and I now see identical behaviour when using an extended-remote target as with the native target. This partially fixes PR gdb/27989, though there are still some issues with newline handling which I'll address in a later commit. During review I was pointed to this older series: https://inbox.sourceware.org/gdb-patches/20211022071933.3478427-1-m.weghorn@posteo.de/ which also includes this fix as part of a larger set of changes. I'm giving a Co-Authored-By credit to the author of that original series. I believe this smaller fix brings some benefits on its own, though the original series does offer additional improvements. Once this is merged I'll take a look at rebasing and resubmitting the original series. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27989 Co-Authored-By: Michael Weghorn Approved-By: Tom Tromey --- gdb/testsuite/gdb.base/args.exp | 4 ++-- gdb/testsuite/gdb.base/inferior-args.exp | 7 +++++-- gdbserver/server.cc | 6 ------ 3 files changed, 7 insertions(+), 10 deletions(-) diff --git a/gdb/testsuite/gdb.base/args.exp b/gdb/testsuite/gdb.base/args.exp index 0b55c4444aa..092b44bd61d 100644 --- a/gdb/testsuite/gdb.base/args.exp +++ b/gdb/testsuite/gdb.base/args.exp @@ -94,10 +94,10 @@ save_vars { GDBFLAGS } { # Try with arguments containing literal single quotes. set GDBFLAGS "$old_gdbflags --args $binfile 1 '' 3" - args_test "one empty with single quotes" {{1} {''} {3}} $single_quotes_newline_kfail + args_test "one empty with single quotes" {{1} {''} {3}} set GDBFLAGS "$old_gdbflags --args $binfile 1 '' '' 3" - args_test "two empty with single quotes" {{1} {''} {''} {3}} $single_quotes_newline_kfail + args_test "two empty with single quotes" {{1} {''} {''} {3}} # try with arguments containing literal newlines. diff --git a/gdb/testsuite/gdb.base/inferior-args.exp b/gdb/testsuite/gdb.base/inferior-args.exp index 19bada6d2c7..3d3cd39a706 100644 --- a/gdb/testsuite/gdb.base/inferior-args.exp +++ b/gdb/testsuite/gdb.base/inferior-args.exp @@ -29,7 +29,7 @@ proc do_test { method } { global binfile hex # The second arg is an empty string on purpose. - set inferior_args { "first arg" "" "third-arg" } + set inferior_args { "first arg" "" "third-arg" "'" "\"" " " } clean_restart $binfile @@ -109,11 +109,14 @@ proc do_test { method } { } # Now that we are stopped at main, inspect argc/argv. - gdb_test "print argc" " = 4" + gdb_test "print argc" " = 7" gdb_test "print argv\[0\]" " = $hex \".*\"" gdb_test "print argv\[1\]" " = $hex \"first arg\"" gdb_test "print argv\[2\]" " = $hex \"\"" gdb_test "print argv\[3\]" " = $hex \"third-arg\"" + gdb_test "print argv\[4\]" " = $hex \"'\"" + gdb_test "print argv\[5\]" " = $hex \"\\\\\"\"" + gdb_test "print argv\[6\]" " = $hex \" \"" } foreach_with_prefix method { "start" "starti" "run" "set args" } { diff --git a/gdbserver/server.cc b/gdbserver/server.cc index c57270175b4..496b9bebb7d 100644 --- a/gdbserver/server.cc +++ b/gdbserver/server.cc @@ -3011,12 +3011,6 @@ handle_v_run (char *own_buf) need_quote = 1; break; - case '\'': - /* Quote single quote. */ - *tmp_full_arg = '\\'; - ++tmp_full_arg; - break; - default: break; } -- 2.30.2