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Subject: Re: [PATCH v2] scripts/gdb: use mem instead of core_layout to get the module address
From:   Kieran Bingham <kieran.bingham@ideasonboard.com>
Cc:     jan.kiszka@siemens.com, kbingham@kernel.org, gost.dev@samsung.com,
        linux-kernel@vger.kernel.org, song@kernel.org,
        Florian Fainelli <f.fainelli@gmail.com>
To:     Luis Chamberlain <mcgrof@kernel.org>,
        Pankaj Raghav <p.raghav@samsung.com>
Date:   Thu, 13 Apr 2023 14:47:30 +0100
Message-ID: <168139365042.2373830.5173244303178460397@Monstersaurus>
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Quoting Pankaj Raghav (2023-04-13 08:44:38)
> On 2023-04-13 02:53, Luis Chamberlain wrote:
> > On Wed, Apr 12, 2023 at 10:25:18PM +0200, Pankaj Raghav wrote:
> >> commit ac3b43283923 ("module: replace module_layout with module_memory=
")
> >> changed the struct module data structure from module_layout to
> >> module_memory. The core_layout member which is used while loading
> >> modules are not available anymore leading to the following error while
> >> running gdb:
> >>
> >> (gdb) lx-symbols
> >> loading vmlinux
> >> Python Exception <class 'gdb.error'>: There is no member named core_la=
yout.
> >> Error occurred in Python: There is no member named core_layout.
> >>
> >> Replace core_layout with its new counterpart mem[MOD_TEXT].
> >>
> >> Fixes: ac3b43283923 ("module: replace module_layout with module_memory=
")
> >> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
> >> ---
> >>  scripts/gdb/linux/constants.py.in | 3 +++
> >>  scripts/gdb/linux/modules.py      | 4 ++--
> >>  scripts/gdb/linux/symbols.py      | 4 ++--
> >>  3 files changed, 7 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/con=
stants.py.in
> >> index 36fd2b145853..471300ba176c 100644
> >> --- a/scripts/gdb/linux/constants.py.in
> >> +++ b/scripts/gdb/linux/constants.py.in
> >> @@ -62,6 +62,9 @@ LX_GDBPARSED(hrtimer_resolution)
> >>  LX_GDBPARSED(IRQD_LEVEL)
> >>  LX_GDBPARSED(IRQ_HIDDEN)
> >> =20
> >> +/* linux/module.h */
> >> +LX_GDBPARSED(MOD_TEXT)
> >=20
> > Should we just fill in the rest of the other sections too while at it?
> >=20
>=20
> I don't see them used in the scripts. Maybe we can add them when needed?

I think there's a runtime-cost to getting these constants, as we
interogate GDB to get the values.

Because of that, I think values should only be added when required,
unless the python code is only lazy-evaluating these.

--
Kieran