Re: [PATCH v2 5/6] test: Move disassembly and extracting PCs earlier

[Kris Van Hees <kris.van.hees@oracle.com>]

On Fri, Dec 20, 2024 at 06:25:47PM -0500, eugene.loh@oracle.com wrote:
> From: Eugene Loh <eugene.loh@oracle.com>
> 
> This will allow a future patch to use the PCs earlier in the test.
> 
> Signed-off-by: Eugene Loh <eugene.loh@oracle.com>

Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com>
> ---
>  test/unittest/usdt/tst.pidprobes.sh | 33 +++++++++++++++++------------
>  1 file changed, 19 insertions(+), 14 deletions(-)
> 
> diff --git a/test/unittest/usdt/tst.pidprobes.sh b/test/unittest/usdt/tst.pidprobes.sh
> index 6fe6d752a..54444d49b 100755
> --- a/test/unittest/usdt/tst.pidprobes.sh
> +++ b/test/unittest/usdt/tst.pidprobes.sh
> @@ -102,6 +102,25 @@ if ! diff -q main.out main.out.expected > /dev/null; then
>  	exit 1
>  fi
>  
> +# Disassemble foo().  (simplify with --disassemble=foo)
> +
> +objdump -d main | awk '
> +BEGIN { use = 0 }             # start by not printing lines
> +use == 1 && NF == 0 { exit }  # if printing lines but hit a blank, then exit
> +use == 1 { print }            # print lines
> +/<foo>:/ { use = 1 }          # turn on printing when we hit "<foo>:" (without printing this line itself)
> +' > disasm_foo.txt
> +if [ $? -ne 0 ]; then
> +	echo cannot objdump main
> +	objdump -d main
> +	exit 1
> +fi
> +
> +# From the disassembly, get the PCs for foo()'s instructions.
> +
> +pcs=`awk '{print strtonum("0x"$1)}' disasm_foo.txt`
> +pc0=`echo $pcs | awk '{print $1}'`
> +
>  # Run dtrace.
>  
>  cat >> pidprobes.d <<'EOF'
> @@ -153,20 +172,6 @@ if [ `awk 'NF != 0 { print $1 }' dtrace.out | uniq | wc -l` -ne 1 ]; then
>  fi
>  pid=`awk 'NF != 0 { print $1 }' dtrace.out | uniq`
>  
> -# Disassemble foo().
> -
> -objdump -d main | awk '
> -BEGIN { use = 0 }             # start by not printing lines
> -use == 1 && NF == 0 { exit }  # if printing lines but hit a blank, then exit
> -use == 1 { print }            # print lines
> -/<foo>:/ { use = 1 }          # turn on printing when we hit "<foo>:" (without printing this line itself)
> -' > disasm_foo.txt
> -
> -# From the disassembly, get the PCs for foo()'s instructions.
> -
> -pcs=`awk '{print strtonum("0x"$1)}' disasm_foo.txt`
> -pc0=`echo $pcs | awk '{print $1}'`
> -
>  # From the disassembly, get the PCs for USDT probes.
>  # Check libdtrace/dt_link.c's arch-dependent dt_modtext() to see
>  # what sequence of instructions signal a USDT probe.
> -- 
> 2.43.5
>