Re: [PATCH] gdb fix for catch-syscall.exp

[Simon Marchi <simark@simark.ca>]

On 2021-11-17 6:30 p.m., Carl Love via Gdb-patches wrote:
> GDB maintainers:
> 
> The following patch fixes three test failures and an expect error.  The
> expect error ERROR: can't read "arch1": no such variable is the result
> of the if/else statement in proc test_catch_syscall_multi_arch not
> matching the power platform.  The power platform, starting with Power
> 8, has "le" in the platform string to indicate a Little Endian system. 
> The current expect string doesn't match the "le" in the name.
> 
> The other three failures are the result of the execve instruction that
> starts executing the new program.  The expect script is looking for the
> return from the execve command which doesn't occur since execve
> replaces the current process image.
> 
> The patch was tested on a Power 10 LE system with no regressions.
> 
> Please let me know if the patch is acceptable for mainline.  Thanks.
> 
>                        Carl 
> 
> 
> -------------------------------------------------------------------
> gdb fix for catch-syscall.exp
> 
> Remove check_continue "execve" from Proc test_catch_syscall_execve.
> 
> The check_continue proceedure checs that the command, execve, starts and
> checks for the return from the command.  The execve command starts a new
> program and thus the return from the command causing the test to fail.
> 
> The call to proc check_continue "execve" is removed and replaced with
> just the call to check_call_to_syscall "execve" to verify the command
> executed.  The next test in proc test_catch_syscall_execve verifies that
> the new program started and hit the break point in main.
> 
> Update the check for the PowerPC architecture.  Power Little Endian systems
> include "le" in the name.  The istarget "power64-*-linux*" check fails to
> match LE sytems.  The expected string is updated to capture both Big Endian
> and Little Endian systems.  Power 10 LE istarget prints as:
> powerpc64le-unknown-linux-gnu.
> 
> This patch fixes three failures and the error:
> 
>     ERROR: can't read "arch1": no such variable
> 
> Patch tested on Power 10 ppc64le GNU/Linux platform.
> ---
>  gdb/testsuite/gdb.base/catch-syscall.exp | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/gdb/testsuite/gdb.base/catch-syscall.exp b/gdb/testsuite/gdb.base/catch-syscall.exp
> index 811a92b0aea..8b496712df5 100644
> --- a/gdb/testsuite/gdb.base/catch-syscall.exp
> +++ b/gdb/testsuite/gdb.base/catch-syscall.exp
> @@ -348,7 +348,9 @@ proc test_catch_syscall_execve {} {
>  	# Check for entry/return across the execve, making sure that the
>  	# syscall_state isn't lost when turning into a new process.
>  	insert_catch_syscall_with_arg "execve"
> -	check_continue "execve"
> +
> +	# check that the execve is called
> +	check_call_to_syscall "execve"
>  
>  	# Continue to main so extended-remote can read files as needed.
>  	# (Otherwise that "Reading" output confuses gdb_continue_to_end.)
> @@ -550,7 +552,7 @@ proc test_catch_syscall_multi_arch {} {
>  	set syscall2_name "write"
>  	set syscall_number 1
>      } elseif { [istarget "powerpc-*-linux*"] \
> -		   || [istarget "powerpc64-*-linux*"] } {
> +		   || [istarget "powerpc64*-linux*"] } {
>  	set arch1 "powerpc:common"
>  	set arch2 "powerpc:common64"
>  	set syscall1_name "openat"
> -- 
> 2.30.2
> 
> 

Hi Carl,

This patch causes this failure regression on Ubuntu 20.04, amd64:

FAIL: gdb.base/catch-syscall.exp: execve: continue to main

From gdb.log:

 615 continue^M
 616 Continuing.^M
 617 process 2022222 is executing new program: /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/catch-syscall/catch-syscall^M
 618 ^M
 619 Catchpoint 18 (returned from syscall execve), 0x00007ffff7fd0100 in _start () from /lib64/ld-linux-x86-64.so.2^M
 620 (gdb) FAIL: gdb.base/catch-syscall.exp: execve: continue to main

Simon