[2/3] perf scripts python: arm-cs-trace-disasm.py: set start vm addr of exectable file to 0

Message ID 20231214123304.34087-3-tianruidong@linux.alibaba.com
State New
Headers
Series perf scripts python: arm-cs-trace-disasm.py: |

Commit Message

Ruidong Tian Dec. 14, 2023, 12:33 p.m. UTC
  For exectable ELF file, which e_type is ET_EXEC, dso start address is a
absolute address other than offset. Just set vm_start to zero when dso
start is 0x400000, which means it is a exectable file.

Signed-off-by: Ruidong Tian <tianruidong@linux.alibaba.com>
---
 tools/perf/scripts/python/arm-cs-trace-disasm.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
  

Comments

James Clark Dec. 20, 2023, 12:06 p.m. UTC | #1
On 14/12/2023 12:33, Ruidong Tian wrote:
> For exectable ELF file, which e_type is ET_EXEC, dso start address is a
> absolute address other than offset. Just set vm_start to zero when dso
> start is 0x400000, which means it is a exectable file.
> 
> Signed-off-by: Ruidong Tian <tianruidong@linux.alibaba.com>
> ---
>  tools/perf/scripts/python/arm-cs-trace-disasm.py | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
> index 46bf6b02eea1..c9e14af5b58c 100755
> --- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
> +++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
> @@ -260,8 +260,9 @@ def process_event(param_dict):
>  
>  	if (options.objdump_name != None):
>  		# It doesn't need to decrease virtual memory offset for disassembly
> -		# for kernel dso, so in this case we set vm_start to zero.
> -		if (dso == "[kernel.kallsyms]"):
> +		# for kernel dso and executable file dso, so in this case we set
> +		# vm_start to zero.
> +		if (dso == "[kernel.kallsyms]" or dso_start == 0x400000):
>  			dso_vm_start = 0
>  		else:
>  			dso_vm_start = int(dso_start)

I confirmed that this fixes the disassembly for static binaries. It
would have been nice to check the type of the file rather than using a
magic number, but it's not that easy and I don't really see a chance of
the number having a false positive.

I wonder if it's worth putting a fixes tag on this one? For the other
ones I'd say no tag as they have a chance of breaking things.

Reviewed-by: James Clark <james.clark@arm.com>
  

Patch

diff --git a/tools/perf/scripts/python/arm-cs-trace-disasm.py b/tools/perf/scripts/python/arm-cs-trace-disasm.py
index 46bf6b02eea1..c9e14af5b58c 100755
--- a/tools/perf/scripts/python/arm-cs-trace-disasm.py
+++ b/tools/perf/scripts/python/arm-cs-trace-disasm.py
@@ -260,8 +260,9 @@  def process_event(param_dict):
 
 	if (options.objdump_name != None):
 		# It doesn't need to decrease virtual memory offset for disassembly
-		# for kernel dso, so in this case we set vm_start to zero.
-		if (dso == "[kernel.kallsyms]"):
+		# for kernel dso and executable file dso, so in this case we set
+		# vm_start to zero.
+		if (dso == "[kernel.kallsyms]" or dso_start == 0x400000):
 			dso_vm_start = 0
 		else:
 			dso_vm_start = int(dso_start)