Re: [PATCH v3] Harden gdb.base/step-over-syscall.exp

[Luis Machado <luis.machado@linaro.org>]

On 1/27/20 3:48 PM, Simon Marchi wrote:
> On 2020-01-27 1:13 p.m., Luis Machado wrote:
>> @@ -75,39 +100,78 @@ proc setup { syscall } {
>>       # Hit the breakpoint on $syscall for the second time.  In this time,
>>       # the address of syscall insn and next insn of syscall are recorded.
>>   
>> -    gdb_test "display/i \$pc" ".*"
>> +    # Check if the first instruction we stopped at is the syscall one.
>> +    set syscall_insn_addr -1
>> +    gdb_test_multiple "display/i \$pc" "fetch first stop pc" {
>> +	-re "display/i .*: x/i .*=> ($hex) .*:.*$syscall_insn.*$gdb_prompt $" {
>> +	    set insn_addr $expect_out(1,string)
>>   
>> -    # Single step until we see a syscall insn or we reach the
>> -    # upper bound of loop iterations.
>> -    set msg "find syscall insn in $syscall"
>> -    set steps 0
>> -    set max_steps 1000
>> -    gdb_test_multiple "stepi" $msg {
>> -	-re ".*$syscall_insn.*$gdb_prompt $" {
>> -	    pass $msg
>> +	    # Is the syscall number the correct one?
>> +	    if {[syscall_number_matches $syscall]} {
>> +		set syscall_insn_addr $insn_addr
>> +	    }
>> +	    pass $gdb_test_name
>>   	}
>> -	-re "x/i .*=>.*\r\n$gdb_prompt $" {
>> -	    incr steps
>> -	    if {$steps == $max_steps} {
>> -		fail $msg
>> -	    } else {
>> -		send_gdb "stepi\n"
>> -		exp_continue
>> +	-re ".*$gdb_prompt $" {
>> +	    pass $gdb_test_name
>> +	}
>> +    }
>> +
>> +    # If we are not at the syscall instruction yet, keep looking for it with
>> +    # stepi commands.
>> +    if {$syscall_insn_addr == -1} {
>> +	# Single step until we see a syscall insn or we reach the
>> +	# upper bound of loop iterations.
>> +	set msg "find syscall insn in $syscall"
> 
> This can be a literal in the gdB_test_multiple call, we don't need `msg`
> anymore.
> 
> The patch LGTM with that fixed.
> 
> Simon
> 

Thanks for the review and suggestions. Pushed now.