Re: [PATCH 1/3] perf scripts python: arm-cs-trace-disasm.py: print dso base address

From: Ruidong Tian
Date: Fri Dec 22 2023 - 02:29:35 EST


Hi James

在 2023/12/20 18:44, James Clark 写道:

On 14/12/2023 12:33, Ruidong Tian wrote:
arm-cs-trace-disasm just print offset for library dso:

0000000000002200 <memcpy>:
2200: d503201f nop
2204: 8b020024 add x4, x1, x2
2208: 8b020005 add x5, x0, x2

This print DSO base address to get complete virtual address for
userspace application:

0000000000002200 <memcpy>: (base address is 0x0000ffffb4c21000)
2200: d503201f nop
2204: 8b020024 add x4, x1, x2
2208: 8b020005 add x5, x0, x2

I believe the output format without the base address is consistent with
objdump. For compatibility I would say that it's better to keep it that way.
Sure, the output is totally corrected, i just print the base address rather than modify the output address, i don't think this change is incompatible.

We could add this as an option, but have it disabled by default. I
suppose it depends how likely that someone is using this output in a
tool and processing it further whether an option is needed or not.
I want to get the runtime trace flow with virtual address, i can get the trace information with virtual address in `perf report` and `perf script` by default, so i think it is more reasonable to print virtual address in arm-cs-trace-disasm script by default.

Although it's also not that clear what this is useful for, given that
all the other output is relative too? Maybe you could add an example to
the commit message, even if it's just for debugging. Would an option
that turned _all_ the output into virtual addresses not be more useful?
I want to use arm-cs-trace-disasm.py output associate with PMU and SPE data to explore more CPU performance info, all the PMU/SPE/Coresight informations generated by `perf report` and `perf script` include virtual address, so i want this script do the same thing.

Thanks
James

Signed-off-by: Ruidong Tian <tianruidong@xxxxxxxxxxxxxxxxx>
---
tools/perf/scripts/python/arm-cs-trace-disasm.py | 2 ++
1 file changed, 2 insertions(+)

diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
index d59ff53f1d94..46bf6b02eea1 100755
--- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
+++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
@@ -108,6 +108,8 @@ def print_disam(dso_fname, dso_start, start_addr, stop_addr):
m = disasm_re.search(line)
if m is None:
continue
+ else:
+ line += " (base address is 0x%016x)" % dso_start
print("\t" + line)
def print_sample(sample):