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From: Jordan Niethe <jniethe5@gmail.com>
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: ajd@linux.ibm.com, Nicholas Piggin <npiggin@gmail.com>,
	cmr@codefail.de, naveen.n.rao@linux.ibm.com,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Daniel Axtens <dja@axtens.net>
Subject: Re: [PATCH v10 04/10] powerpc/kprobes: Mark newly allocated probes as ROX
Date: Wed, 21 Apr 2021 12:39:15 +1000
Message-ID: <CACzsE9p4cOmdXKvcgBRDFT=CEQkrvJoJ+LEDU4E5FGBpdoXJxA@mail.gmail.com> (raw)
In-Reply-To: <d61a1b2f-4a22-fb43-e8fe-a7612431c4ad@csgroup.eu>

On Tue, Mar 30, 2021 at 4:05 PM Christophe Leroy
<christophe.leroy@csgroup.eu> wrote:
>
>
>
> Le 30/03/2021 à 06:51, Jordan Niethe a écrit :
> > From: Russell Currey <ruscur@russell.cc>
> >
> > Add the arch specific insn page allocator for powerpc. This allocates
> > ROX pages if STRICT_KERNEL_RWX is enabled. These pages are only written
> > to with patch_instruction() which is able to write RO pages.
> >
> > Reviewed-by: Daniel Axtens <dja@axtens.net>
> > Signed-off-by: Russell Currey <ruscur@russell.cc>
> > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> > [jpn: Reword commit message, switch to __vmalloc_node_range()]
> > Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
> > ---
> > v9: - vmalloc_exec() no longer exists
> >      - Set the page to RW before freeing it
> > v10: - use __vmalloc_node_range()
> > ---
> >   arch/powerpc/kernel/kprobes.c | 14 ++++++++++++++
> >   1 file changed, 14 insertions(+)
> >
> > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
> > index 01ab2163659e..3ae27af9b094 100644
> > --- a/arch/powerpc/kernel/kprobes.c
> > +++ b/arch/powerpc/kernel/kprobes.c
> > @@ -25,6 +25,7 @@
> >   #include <asm/sections.h>
> >   #include <asm/inst.h>
> >   #include <linux/uaccess.h>
> > +#include <linux/vmalloc.h>
> >
> >   DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
> >   DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
> > @@ -103,6 +104,19 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
> >       return addr;
> >   }
> >
> > +void *alloc_insn_page(void)
> > +{
> > +     if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
> > +             return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR, MODULES_END,
> > +                             GFP_KERNEL, PAGE_KERNEL_ROX, VM_FLUSH_RESET_PERMS,
> > +                             NUMA_NO_NODE, __builtin_return_address(0));
> > +     } else {
> > +             return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR, MODULES_END,
> > +                             GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS,
> > +                             NUMA_NO_NODE, __builtin_return_address(0));
> > +     }
> > +}
> > +
>
> What about
>
> void *alloc_insn_page(void)
> {
>         pgprot_t prot = IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
>
>         return __vmalloc_node_range(PAGE_SIZE, 1, MODULES_VADDR, MODULES_END,
>                         GFP_KERNEL, prot, VM_FLUSH_RESET_PERMS,
>                         NUMA_NO_NODE, __builtin_return_address(0));
> }
Yes, that is better.
>
> >   int arch_prepare_kprobe(struct kprobe *p)
> >   {
> >       int ret = 0;
> >

  reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30  4:51 [PATCH v10 00/10] powerpc: Further Strict RWX support Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 01/10] powerpc/mm: Implement set_memory() routines Jordan Niethe
2021-03-30  5:16   ` Christophe Leroy
2021-04-21  2:51     ` Jordan Niethe
2021-03-31 11:16   ` Michael Ellerman
2021-03-31 12:03     ` Christophe Leroy
2021-04-21  5:03     ` Jordan Niethe
2021-04-01  4:37   ` Aneesh Kumar K.V
2021-04-21  5:19     ` Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 02/10] powerpc/lib/code-patching: Set up Strict RWX patching earlier Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 03/10] powerpc: Always define MODULES_{VADDR,END} Jordan Niethe
2021-03-30  5:00   ` Christophe Leroy
2021-04-01 13:36   ` Christophe Leroy
2021-04-21  2:46     ` Jordan Niethe
2021-04-21  5:14       ` Christophe Leroy
2021-04-21  5:22         ` Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 04/10] powerpc/kprobes: Mark newly allocated probes as ROX Jordan Niethe
2021-03-30  5:05   ` Christophe Leroy
2021-04-21  2:39     ` Jordan Niethe [this message]
2021-03-30  4:51 ` [PATCH v10 05/10] powerpc/bpf: Write protect JIT code Jordan Niethe
2021-03-31 10:37   ` Michael Ellerman
2021-03-31 10:39     ` Christophe Leroy
2021-04-21  2:35     ` Jordan Niethe
2021-04-21  6:51       ` Michael Ellerman
2021-03-30  4:51 ` [PATCH v10 06/10] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime Jordan Niethe
2021-03-31 11:24   ` Michael Ellerman
2021-04-21  2:23     ` Jordan Niethe
2021-04-21  5:16       ` Christophe Leroy
2021-03-30  4:51 ` [PATCH v10 07/10] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 08/10] powerpc/configs: Enable STRICT_MODULE_RWX in skiroot_defconfig Jordan Niethe
2021-03-30  5:27   ` Christophe Leroy
2021-04-21  2:37     ` Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 09/10] powerpc/mm: implement set_memory_attr() Jordan Niethe
2021-03-30  4:51 ` [PATCH v10 10/10] powerpc/32: use set_memory_attr() Jordan Niethe

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