From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Anton Arapov <anton@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Josh Stone <jistone@redhat.com>, Frank Eigler <fche@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
adrian.m.negreanu@intel.com, Torsten.Polle@gmx.de
Subject: Re: [PATCH v1 3/9] uretprobes/x86: Hijack return address
Date: Sun, 7 Apr 2013 17:18:59 +0530 [thread overview]
Message-ID: <20130407114859.GC2186@linux.vnet.ibm.com> (raw)
In-Reply-To: <1365004839-21982-4-git-send-email-anton@redhat.com>
* Anton Arapov <anton@redhat.com> [2013-04-03 18:00:33]:
> Hijack the return address and replace it with a trampoline address.
>
> v1 changes:
> * use force_sig_info()
> * rework and simplify logic
>
> RFCv5 changes:
> * change the fail return code, because orig_ret_vaddr=0 is possible
> * style fixup
> RFCv2 changes:
> * remove ->doomed flag, kill task immediately
>
> Signed-off-by: Anton Arapov <anton@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> ---
> arch/x86/include/asm/uprobes.h | 1 +
> arch/x86/kernel/uprobes.c | 29 +++++++++++++++++++++++++++++
> 2 files changed, 30 insertions(+)
>
> diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h
> index 8ff8be7..6e51979 100644
> --- a/arch/x86/include/asm/uprobes.h
> +++ b/arch/x86/include/asm/uprobes.h
> @@ -55,4 +55,5 @@ extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
> extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
> extern int arch_uprobe_exception_notify(struct notifier_block *self, unsigned long val, void *data);
> extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs);
> +extern unsigned long arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs);
> #endif /* _ASM_UPROBES_H */
> diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
> index 0ba4cfb..2ed8459 100644
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -697,3 +697,32 @@ bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
> send_sig(SIGTRAP, current, 0);
> return ret;
> }
> +
> +unsigned long
> +arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr, struct pt_regs *regs)
> +{
> + int rasize, ncopied;
> + unsigned long orig_ret_vaddr = 0; /* clear high bits for 32-bit apps */
> +
> + rasize = is_ia32_task() ? 4 : 8;
> + ncopied = copy_from_user(&orig_ret_vaddr, (void __user *)regs->sp, rasize);
> + if (unlikely(ncopied))
> + return -1;
> +
> + /* check whether address has been already hijacked */
> + if (orig_ret_vaddr == trampoline_vaddr)
> + return orig_ret_vaddr;
> +
> + ncopied = copy_to_user((void __user *)regs->sp, &trampoline_vaddr, rasize);
> + if (likely(!ncopied))
> + return orig_ret_vaddr;
> +
> + if (ncopied != rasize) {
> + pr_err("uprobe: return address clobbered: pid=%d, %%sp=%#lx, "
> + "%%ip=%#lx\n", current->pid, regs->sp, regs->ip);
> +
> + force_sig_info(SIGSEGV, SEND_SIG_FORCED, current);
> + }
> +
> + return -1;
> +}
> --
> 1.8.1.4
>
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2013-04-07 11:54 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-03 16:00 [PATCH v1 0/9] uretprobes: Return uprobes implementation Anton Arapov
2013-04-03 16:00 ` [PATCH v1 1/9] uretprobes: Introduce uprobe_consumer->ret_handler() Anton Arapov
2013-04-07 11:37 ` Srikar Dronamraju
2013-04-03 16:00 ` [PATCH v1 2/9] uretprobes: Reserve the first slot in xol_vma for trampoline Anton Arapov
2013-04-07 11:44 ` Srikar Dronamraju
2013-04-09 14:16 ` Oleg Nesterov
2013-04-03 16:00 ` [PATCH v1 3/9] uretprobes/x86: Hijack return address Anton Arapov
2013-04-07 11:48 ` Srikar Dronamraju [this message]
2013-04-03 16:00 ` [PATCH v1 4/9] uretprobes/ppc: " Anton Arapov
2013-04-04 3:31 ` Ananth N Mavinakayanahalli
2013-04-07 11:51 ` Srikar Dronamraju
2013-04-03 16:00 ` [PATCH v1 5/9] uretprobes: Return probe entry, prepare_uretprobe() Anton Arapov
2013-04-07 11:52 ` Srikar Dronamraju
2013-04-03 16:00 ` [PATCH v1 6/9] uretprobes: Return probe exit, invoke handlers Anton Arapov
2013-04-07 10:53 ` Srikar Dronamraju
2013-04-09 14:05 ` Oleg Nesterov
2013-04-09 20:13 ` Oleg Nesterov
2013-04-13 10:01 ` Srikar Dronamraju
2013-04-13 16:10 ` Oleg Nesterov
2013-04-03 16:00 ` [PATCH v1 7/9] uretprobes: Limit the depth of return probe nestedness Anton Arapov
2013-04-07 11:55 ` Srikar Dronamraju
2013-04-03 16:00 ` [PATCH v1 8/9] uretprobes: Remove -ENOSYS as return probes implemented Anton Arapov
2013-04-07 11:56 ` Srikar Dronamraju
2013-04-03 16:00 ` [PATCH v1 9/9] uretprobes: Documentation update Anton Arapov
2013-04-07 11:57 ` Srikar Dronamraju
2013-04-03 17:45 ` [PATCH v1 0/9] uretprobes: Return uprobes implementation Oleg Nesterov
2013-04-04 3:32 ` Ananth N Mavinakayanahalli
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