From: Oleg Nesterov <oleg@redhat.com>
To: David Long <dave.long@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org,
Rabin Vincent <rabin@rab.in>,
"Jon Medhurst (Tixy)" <tixy@linaro.org>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Subject: [PATCH] uprobes: introduce arch_uprobe->ixol
Date: Mon, 4 Nov 2013 20:49:01 +0100 [thread overview]
Message-ID: <20131104194901.GA28022@redhat.com> (raw)
In-Reply-To: <20131029154006.GA22344@redhat.com>
On 10/29, Oleg Nesterov wrote:
>
> David. Perhaps we can avoid the new hook altogether? What if we do
> the simple change below (it ignores powerpc) ?
>
> Then arm can add "unsigned long ixol[2]" into its arch_uprobe, and
> arch_uprobe_analyze_insn() can initialize this member correctly.
>
> What do you think?
Seriouly, how about the patch below?
In fact, given that you are going to reimplement set_swbp/orig_insn,
the new member is not strictly needed (afaics). But it looks more
clear this way, and we need s/MAX_UINSN_BYTES/sizeof()/ anyway.
Oleg.
---
Subject: [PATCH] uprobes: introduce arch_uprobe->ixol
Currently xol_get_insn_slot() assumes that we should simply copy
arch_uprobe->insn[] which is (ignoring arch_uprobe_analyze_insn)
just the copy of the original insn.
This is not true for arm which needs to create another insn to
execute it out-of-line.
So this patch simply adds the new member, ->ixol into the union.
This doesn't make any difference for x86 and powerpc, but arm
can divorce insn/ixol and initialize the correct xol insn in
arch_uprobe_analyze_insn().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
arch/powerpc/include/asm/uprobes.h | 1 +
arch/x86/include/asm/uprobes.h | 5 ++++-
kernel/events/uprobes.c | 3 ++-
3 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/uprobes.h b/arch/powerpc/include/asm/uprobes.h
index 2301602..541fd6f 100644
--- a/arch/powerpc/include/asm/uprobes.h
+++ b/arch/powerpc/include/asm/uprobes.h
@@ -37,6 +37,7 @@ typedef ppc_opcode_t uprobe_opcode_t;
struct arch_uprobe {
union {
u8 insn[MAX_UINSN_BYTES];
+ u8 ixol[MAX_UINSN_BYTES];
u32 ainsn;
};
};
diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
index 6e51979..2a24180 100644
--- a/arch/x86/include/asm/uprobes.h
+++ b/arch/x86/include/asm/uprobes.h
@@ -35,7 +35,10 @@ typedef u8 uprobe_opcode_t;
struct arch_uprobe {
u16 fixups;
- u8 insn[MAX_UINSN_BYTES];
+ union {
+ u8 insn[MAX_UINSN_BYTES];
+ u8 ixol[MAX_UINSN_BYTES];
+ };
#ifdef CONFIG_X86_64
unsigned long rip_rela_target_address;
#endif
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ad8e1bd..6aef5ad 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1256,7 +1256,8 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe)
return 0;
/* Initialize the slot */
- copy_to_page(area->page, xol_vaddr, uprobe->arch.insn, MAX_UINSN_BYTES);
+ copy_to_page(area->page, xol_vaddr,
+ uprobe->arch.ixol, sizeof(uprobe->arch.ixol));
/*
* We probably need flush_icache_user_range() but it needs vma.
* This should work on supported architectures too.
--
1.5.5.1
next prev parent reply other threads:[~2013-11-04 19:47 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-15 21:04 [PATCH v2 00/13] uprobes: Add uprobes support for ARM David Long
2013-10-15 21:04 ` [PATCH v2 01/13] uprobes: move function declarations out of arch David Long
2013-11-05 16:01 ` Oleg Nesterov
2013-11-05 18:16 ` Oleg Nesterov
2013-11-05 19:01 ` [PATCH] uprobes: Export write_opcode() as uprobe_write_opcode() Oleg Nesterov
2013-11-05 19:55 ` David Long
2013-11-05 19:13 ` [PATCH v2 01/13] uprobes: move function declarations out of arch David Long
2013-10-15 21:04 ` [PATCH v2 02/13] uprobes: allow ignoring of probe hits David Long
2013-10-19 17:02 ` Oleg Nesterov
2013-10-22 3:45 ` David Long
2013-10-22 11:25 ` Oleg Nesterov
2013-10-22 23:56 ` David Long
2013-10-28 18:54 ` Oleg Nesterov
2013-10-30 21:11 ` David Long
2013-10-15 21:04 ` [PATCH v2 03/13] uprobes: allow arch access to xol slot David Long
2013-10-19 16:36 ` Oleg Nesterov
2013-10-23 0:03 ` David Long
2013-10-29 15:40 ` Oleg Nesterov
2013-11-04 19:49 ` Oleg Nesterov [this message]
2013-11-04 21:25 ` [PATCH] uprobes: introduce arch_uprobe->ixol David Long
2013-11-05 16:04 ` David Long
2013-11-05 18:01 ` Oleg Nesterov
2013-11-05 18:45 ` David Long
2013-10-15 21:04 ` [PATCH v2 04/13] uprobes: allow arch-specific initialization David Long
2013-10-19 16:42 ` Oleg Nesterov
2013-10-23 1:21 ` David Long
2013-10-28 18:58 ` Oleg Nesterov
2013-10-31 18:41 ` David Long
2013-11-01 13:52 ` Oleg Nesterov
2013-11-04 3:24 ` David Long
2013-10-15 21:04 ` [PATCH v2 05/13] uprobes: add arch write opcode hook David Long
2013-10-19 16:50 ` Oleg Nesterov
2013-10-23 18:20 ` David Long
2013-10-28 19:49 ` Oleg Nesterov
2013-10-29 19:59 ` Oleg Nesterov
2013-11-02 3:33 ` David Long
2013-11-02 14:03 ` Oleg Nesterov
2013-10-15 21:04 ` [PATCH v2 06/13] ARM: move shared uprobe/kprobe definitions into new include file David Long
2013-10-15 21:04 ` [PATCH v2 07/13] ARM: move generic thumb instruction parsing code to new files for use by other features David Long
2013-11-13 17:09 ` Jon Medhurst (Tixy)
2013-11-14 14:13 ` David Long
2013-10-15 21:04 ` [PATCH v2 08/13] ARM: use a function table for determining instruction interpreter actions David Long
2013-11-13 17:11 ` Jon Medhurst (Tixy)
2013-11-14 15:17 ` David Long
2013-10-15 21:04 ` [PATCH v2 09/13] ARM: Disable jprobe selftests in thumb kernels David Long
2013-11-07 17:26 ` Jon Medhurst (Tixy)
2013-11-10 22:57 ` David Long
2013-10-15 21:04 ` [PATCH v2 10/13] kprobes: Remove uneeded kernel dependency on struct arch_specific_insn David Long
2013-11-13 17:13 ` Jon Medhurst (Tixy)
2013-11-14 2:02 ` Masami Hiramatsu
2013-11-14 14:15 ` Jon Medhurst (Tixy)
2013-11-14 20:33 ` David Long
2013-11-15 10:23 ` Masami Hiramatsu
2013-11-15 15:16 ` David Long
2013-11-15 10:11 ` Re: " Masami Hiramatsu
2013-11-14 1:20 ` Masami Hiramatsu
2013-10-15 21:04 ` [PATCH v2 11/13] ARM: Finish renaming ARM kprobes APIs for sharing with uprobes David Long
2013-11-13 17:16 ` Jon Medhurst (Tixy)
2013-11-15 15:45 ` David Long
2013-10-15 21:04 ` [PATCH v2 12/13] ARM: add uprobes support David Long
2013-10-15 21:04 ` [PATCH v2 13/13] ARM: Remove uprobes dependency on kprobes David Long
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