From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Mike Rapoport <rppt@kernel.org>
Cc: linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>
Subject: Re: [PATCH v4 3/7] vmalloc: Add text_alloc() and text_free()
Date: Fri, 24 Jul 2020 01:28:35 +0300 [thread overview]
Message-ID: <20200723222835.GC12405@linux.intel.com> (raw)
In-Reply-To: <20200718162359.GA2919062@kernel.org>
On Sat, Jul 18, 2020 at 07:23:59PM +0300, Mike Rapoport wrote:
> On Fri, Jul 17, 2020 at 06:04:17AM +0300, Jarkko Sakkinen wrote:
> > Introduce functions for allocating memory for dynamic trampolines, such
> > as kprobes. An arch can promote the availability of these functions with
> > CONFIG_ARCH_HAS_TEXT_ALLOC. Provide default/fallback implementation
> > wrapping module_alloc() and module_memfree().
> >
> > Cc: Andi Kleen <ak@linux.intel.com>
> > Cc: Masami Hiramatsu <mhiramat@kernel.org>
> > Suggested-by: Peter Zijlstra <peterz@infradead.org>
> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > ---
> > include/linux/vmalloc.h | 23 +++++++++++++++++++++++
> > 1 file changed, 23 insertions(+)
> >
> > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> > index 0221f852a7e1..e981436e30b6 100644
> > --- a/include/linux/vmalloc.h
> > +++ b/include/linux/vmalloc.h
> > @@ -9,6 +9,7 @@
> > #include <asm/page.h> /* pgprot_t */
> > #include <linux/rbtree.h>
> > #include <linux/overflow.h>
> > +#include <linux/moduleloader.h>
> >
> > #include <asm/vmalloc.h>
> >
> > @@ -249,4 +250,26 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
> > int register_vmap_purge_notifier(struct notifier_block *nb);
> > int unregister_vmap_purge_notifier(struct notifier_block *nb);
> >
> > +#ifdef CONFIG_ARCH_HAS_TEXT_ALLOC
> > +/*
> > + * Allocate memory to be used for dynamic trampoline code.
> > + */
> > +void *text_alloc(unsigned long size);
> > +
> > +/*
> > + * Free memory returned from text_alloc().
> > + */
> > +void text_free(void *region);
> > +#else
> > +static inline void *text_alloc(unsigned long size)
> > +{
> > + return module_alloc(size);
> > +}
> > +
> > +static inline void text_free(void *region)
> > +{
> > + module_memfree(region);
> > +}
>
> Using module_alloc() as the default implementation of generic
> text_alloc() does not sound right to me.
>
> I would suggest rename module_alloc() to text_alloc() on x86, as Peter
> proposed and then add text_alloc_kprobes() that can be overridden by the
> architectures. x86 could use text_alloc(), arm64 vmalloc() with options
> of their choice and the fallback would remain module_alloc(). Something
> like (untested) patch below:
I'm not exactly sure which of the below is relevant as the patch set
includes the exact same changes with maybe different phrasing:
https://lore.kernel.org/lkml/20200717030422.679972-1-jarkko.sakkinen@linux.intel.com/
If there is something that these patches are missing, please do remark
but these seven patches have been at least tested and split in
reasonable manner.
/Jarkko
next prev parent reply other threads:[~2020-07-23 22:28 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-17 3:04 [PATCH v4 0/7] arch/x86: kprobes: Remove MODULES dependency Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 1/7] module: Add lock_modules() and unlock_modules() Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 2/7] kprobes: Use " Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 3/7] vmalloc: Add text_alloc() and text_free() Jarkko Sakkinen
2020-07-17 5:33 ` kernel test robot
2020-07-17 5:33 ` kernel test robot
2020-07-17 8:52 ` Masami Hiramatsu
2020-07-23 22:24 ` Jarkko Sakkinen
2020-07-18 16:23 ` Mike Rapoport
2020-07-20 12:01 ` Masami Hiramatsu
2020-07-23 22:28 ` Jarkko Sakkinen [this message]
2020-07-24 10:13 ` Mike Rapoport
2020-07-24 23:31 ` Jarkko Sakkinen
2020-07-24 23:40 ` Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 4/7] arch/x86: Implement " Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 5/7] arch/x86: kprobes: Use text_alloc() in alloc_insn_page() Jarkko Sakkinen
2020-07-23 22:16 ` Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 6/7] kprobes: Use text_alloc() and text_free() Jarkko Sakkinen
2020-07-17 3:04 ` [PATCH v4 7/7] kprobes: Flag out CONFIG_MODULES dependent code Jarkko Sakkinen
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