From: Oleg Nesterov <oleg@redhat.com>
To: David Windsor <dwindsor@gmail.com>
Cc: mhiramat@kernel.org, peterz@infradead.org, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
x86@kernel.org, shuah@kernel.org,
linux-trace-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] x86/uprobes: Keep shadow stack in sync for emulated CALLs
Date: Tue, 23 Jun 2026 14:52:32 +0200 [thread overview]
Message-ID: <ajqBkKE8TpQL1mIG@redhat.com> (raw)
In-Reply-To: <20260622183109.1137245-1-dwindsor@gmail.com>
On 06/22, David Windsor wrote:
>
> --- a/arch/x86/kernel/uprobes.c
> +++ b/arch/x86/kernel/uprobes.c
> @@ -1246,8 +1246,12 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs
> long correction = utask->vaddr - utask->xol_vaddr;
> regs->ip += correction;
> } else if (auprobe->defparam.fixups & UPROBE_FIX_CALL) {
> + unsigned long retaddr = utask->vaddr + auprobe->defparam.ilen;
> +
> regs->sp += sizeof_long(regs); /* Pop incorrect return address */
> - if (emulate_push_stack(regs, utask->vaddr + auprobe->defparam.ilen))
> + if (emulate_push_stack(regs, retaddr))
> + return -ERESTART;
> + if (shstk_update_last_frame(retaddr))
> return -ERESTART;
Well, if shstk_update_last_frame() fails after emulate_push_stack(), we should
probably return another error, so that the caller handle_singlestep() will kill
this task?
Oleg.
next prev parent reply other threads:[~2026-06-23 12:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-22 18:31 [PATCH 1/2] x86/uprobes: Keep shadow stack in sync for emulated CALLs David Windsor
2026-06-22 18:31 ` [PATCH 2/2] selftests/x86: Add shadow stack uprobe CALL test David Windsor
2026-06-23 8:43 ` [PATCH 1/2] x86/uprobes: Keep shadow stack in sync for emulated CALLs Peter Zijlstra
2026-06-23 14:07 ` David Windsor
2026-06-23 12:52 ` Oleg Nesterov [this message]
2026-06-23 12:57 ` Peter Zijlstra
2026-06-23 13:25 ` Oleg Nesterov
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