Re: [PATCH] Harden gdb.arch/aarch64-pauth.exp and fix a failure

[Kevin Buettner <kevinb at redhat dot com>]

On Fri, 21 Feb 2020 18:06:28 -0300
Luis Machado <luis.machado@linaro.org> wrote:

> When running this testcase against a QEMU with PAC support, i noticed we
> were failing to recognize the additional [PAC] that is emitted in the
> backtrace, resulting in this failure:
> 
> FAIL: gdb.arch/aarch64-pauth.exp: backtrace
> 
> I've made the test use multi_line to make the pattern more clear.
> 
> Tested against aarch64-linux-gnu with and without PAC support.
> 
> gdb/testsuite/ChangeLog:
> 
> 2020-02-21  Luis Machado  <luis.machado@linaro.org>
> 
> 	* gdb.arch/aarch64-pauth.exp: Recognize optional PAC output.
> 
> Signed-off-by: Luis Machado <luis.machado@linaro.org>
> ---
>  gdb/testsuite/gdb.arch/aarch64-pauth.exp | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.arch/aarch64-pauth.exp b/gdb/testsuite/gdb.arch/aarch64-pauth.exp
> index 816e58be44..e6d25c5d97 100644
> --- a/gdb/testsuite/gdb.arch/aarch64-pauth.exp
> +++ b/gdb/testsuite/gdb.arch/aarch64-pauth.exp
> @@ -40,4 +40,9 @@ gdb_breakpoint [ gdb_get_line_number "break here" ]
>  gdb_continue_to_breakpoint "break here" ".*break here.*"
>  
>  # Ensure we can get a full backtrace, despite the address signing.
> -gdb_test "bt" "^bt\r\n#0 +bar *\\(b=9\\) +at.*\r\n#1 +0x\[0-9a-f\]* +in +foo \\(a=5\\).*\r\n#2 +0x\[0-9a-f\]* +in +main \\(\\).*" "backtrace"
> +gdb_test "bt" \
> +    [multi_line \
> +	"#0\[ \t\]*bar \\(b=9\\) at \[^\r\n\]+" \
> +	"#1\[ \t\]*$hex (\\\[PAC\\\] )?in foo \\(a=5\\) at \[^\r\n\]+" \
> +	"#2\[ \t\]*$hex (\\\[PAC\\\] )?in main \\(\\) at \[^\r\n\]+" ] \
> +    "backtrace"

LGTM except for the \[ \t\]* parts of it.  I think we actually want +
instead of * to ensure that there's whitespace separating the frame
number from the hex value.

Kevin