Re: [PATCH v4 01/23] perf capstone: Fix arm64 jump/adrp disassembly mismatch with objdump

[Shuai Xue]

On 8/11/26 10:27 AM, Tengda Wu wrote:
> Hi Shuai, thank you for your time.
>
> On 2026/8/10 21:08, Shuai Xue wrote:
> > On 8/8/26 8:23 PM, Tengda Wu wrote:
> > > The jump and adrp instructions parsed by libcapstone currently lack
> > > symbolic representation and use a '#' prefix for addresses. This
> > > format is inconsistent with objdump's output, which causes subsequent
> > > parsing in jump__parse() and arm64_mov__parse() to fail.
> > >
> > > Example mismatch:
> > >     Current: b #0xffff8000800114c8
> > >     Fix:     b ffff8000800114c8 <el0t_64_sync+0x108>
> > >
> > >     Current: adrp x18, #0xffff800081f5f000
> > >     Fix:     adrp x18, ffff800081f5f000 <this_cpu_vector>
> > >
> > > Fix this by implementing extended formatting for these arm64
> > > instructions during symbol__disassemble_capstone(). This ensures
> > > the output matches objdump's expected style, including the raw
> > > address and the associated <symbol+offset> suffix.
> > >
> > > Signed-off-by: Tengda Wu <wutengda@xxxxxxxxxxxxxxx>
> > > ---
> > >    tools/perf/util/capstone.c | 136 +++++++++++++++++++++++++++++++++----
> > >    tools/perf/util/disasm.c   |   5 ++
> > >    tools/perf/util/disasm.h   |   1 +
> > >    3 files changed, 130 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/tools/perf/util/capstone.c b/tools/perf/util/capstone.c
> > > index 74213daf8786..fb8a2bc5558f 100644
> > > --- a/tools/perf/util/capstone.c
> > > +++ b/tools/perf/util/capstone.c
> > > @@ -3,6 +3,7 @@
> > >      #include <errno.h>
> > >    #include <inttypes.h>
> > > +#include <stdlib.h>
> > >    #include <string.h>
> > >      #include <dlfcn.h>
> > > @@ -31,6 +32,10 @@
> > >    #define CS_MODE_RISCVC   4
> > >    #endif
> > >    +#if CS_VERSION_MAJOR < 4
> > > +#define ARM64_GRP_BRANCH_RELATIVE  7
> >
> > Please add a comment explaining where '7' comes from
> > (CS_GRP_BRANCH_RELATIVE in capstone v3), otherwise it reads like an
> > arbitrary magic number.
>
> Um, this was done following Namhyung's approach. That said, adding a
> comment would certainly make this definition clearer -- will add it.
>
> Also, I couldn't find CS_GRP_BRANCH_RELATIVE in v3. From what I can see,
> it was originally introduced in v4, together with ARM64_GRP_BRANCH_RELATIVE
> (see https://github.com/capstone-engine/capstone/commit/a09a81813c83).
> So the comment might look something like this:
>
>    #define ARM64_GRP_BRANCH_RELATIVE  7  /* = CS_GRP_BRANCH_RELATIVE */
>
> Is this acceptable?

LGTM.

Thanks.
Shuai