From: alexander.sverdlin@nokia.com (Alexander Sverdlin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 2/2] ARM: ftrace: Add MODULE_PLTS support
Date: Tue, 13 Mar 2018 18:13:25 +0100 [thread overview]
Message-ID: <5d3ae760-45bd-3588-500f-1b352e1722de@nokia.com> (raw)
In-Reply-To: <CAKv+Gu-g+2y6Ej0cvLcz0R571HAnj2VXXDF0agWizDzReYMymg@mail.gmail.com>
Hello Ard,
On 13/03/18 17:12, Ard Biesheuvel wrote:
>> u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val)
>> {
>> struct mod_plt_sec *pltsec = !in_init(mod, loc) ? &mod->arch.core :
>> &mod->arch.init;
>> + struct plt_entries *plt;
>> + int idx;
>>
>> - struct plt_entries *plt = (struct plt_entries *)pltsec->plt->sh_addr;
^^^^^^^^^^^ (*)
>> - int idx = 0;
>> + /* cache the address, ELF header is available only during module load */
>> + if (!pltsec->plt_ent)
>> + pltsec->plt_ent = (struct plt_entries *)pltsec->plt->sh_addr;
>> + plt = pltsec->plt_ent;
>> +
> Where is plt_ent ever used?
Above is exactly the place it's used.
I need to cache it because after the module load is finished the ELF header is freed,
pltsec->plt pointer (*) is not valid any more.
With the above modification it's possible to call the function during the whole life
time of the module.
>> + if (!pltsec->plt_count)
>> + prealloc_fixed(pltsec, plt);
I'll prepare v5 based on your other comments.
--
Best regards,
Alexander Sverdlin.
next prev parent reply other threads:[~2018-03-13 17:13 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 13:53 [PATCH v4 0/2] ARM: Implement MODULE_PLT support in FTRACE Alexander Sverdlin
2018-03-13 13:53 ` [PATCH v4 1/2] ARM: PLT: Move struct plt_entries definition to header Alexander Sverdlin
2018-03-13 13:53 ` [PATCH v4 2/2] ARM: ftrace: Add MODULE_PLTS support Alexander Sverdlin
2018-03-13 16:12 ` Ard Biesheuvel
2018-03-13 17:13 ` Alexander Sverdlin [this message]
2018-03-13 17:18 ` Ard Biesheuvel
2018-03-13 17:32 ` Alexander Sverdlin
2018-03-13 17:39 ` Ard Biesheuvel
2018-03-13 17:49 ` Alexander Sverdlin
2018-03-13 17:51 ` Ard Biesheuvel
2018-03-13 18:24 ` Alexander Sverdlin
2018-03-13 18:29 ` Ard Biesheuvel
2018-03-13 18:28 ` Alexander Sverdlin
2018-03-20 12:28 ` Alexander Sverdlin
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