From: Andi Kleen <ak@muc.de>
To: prasanna@in.ibm.com
Cc: Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, maneesh@in.ibm.com, stsp@aknet.ru
Subject: Re: [patch] kprobes: dont steal interrupts from vm86
Date: Fri, 07 Jan 2005 13:59:51 +0100 [thread overview]
Message-ID: <m1ekgxv1h4.fsf@muc.de> (raw)
In-Reply-To: <20050107113732.GB16906@in.ibm.com> (Prasanna S. Panchamukhi's message of "Fri, 7 Jan 2005 17:07:32 +0530")
Prasanna S Panchamukhi <prasanna@in.ibm.com> writes:
> + /* Check if the application is using LDT entry for its code segment and
> + * calculate the address by reading the base address from the LDT entry.
> + */
> + if ((regs->xcs & 4) && (current->mm)) {
> + lp = (unsigned long *) ((unsigned long)((regs->xcs >> 3) * 8)
> + + (char *) current->mm->context.ldt);
> + addr = (kprobe_opcode_t *) ((((*lp) >> 16 & 0x0000ffff)
> + | (*(lp +1) & 0xff000000)
> + | ((*(lp +1) << 16) & 0x00ff0000))
> + + regs->eip - sizeof(kprobe_opcode_t));
> + } else {
> + addr = (kprobe_opcode_t *)(regs->eip - sizeof(kprobe_opcode_t));
> + }
With that patch we would have LDT reading code three times in the kernel
now (ptrace, prefetch workaround and now this). How about you factor
this out into a common helper function? This stuff is tricky enough
that there are likely bugs in there anyways and it would be best
to only fix them at one place then.
-Andi
next prev parent reply other threads:[~2005-01-07 12:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20041109130407.6d7faf10.akpm@osdl.org>
2004-11-10 10:49 ` [patch] kprobes: dont steal interrupts from vm86 Prasanna S Panchamukhi
2004-11-10 18:53 ` Stas Sergeev
2004-11-17 13:15 ` Prasanna S Panchamukhi
2004-11-18 14:55 ` Stas Sergeev
2004-12-02 19:28 ` Stas Sergeev
2004-12-06 15:28 ` Prasanna S Panchamukhi
2004-12-04 18:09 ` Stas Sergeev
2004-12-07 5:53 ` Prasanna S Panchamukhi
2004-12-07 18:44 ` Stas Sergeev
2004-12-09 12:47 ` Prasanna S Panchamukhi
2004-12-09 19:28 ` Stas Sergeev
2005-01-07 11:37 ` Prasanna S Panchamukhi
2005-01-07 12:59 ` Andi Kleen [this message]
2005-01-13 8:10 ` Prasanna S Panchamukhi
2005-01-07 22:44 ` Stas Sergeev
2004-11-09 19:01 Stas Sergeev
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