From: "Fernando Luis Vázquez Cao" <fernando@oss.ntt.co.jp>
To: Andi Kleen <ak@suse.de>
Cc: prasanna@in.ibm.com, akpm@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] i386: Disallow kprobes on NMI handlers
Date: Thu, 10 Aug 2006 19:40:55 +0900 [thread overview]
Message-ID: <1155206455.4141.2.camel@localhost.localdomain> (raw)
In-Reply-To: <1155206199.3001.40.camel@localhost.localdomain>
This version of the patch does not compile. I will fix this problem and
resend it.
Sorry for the noise.
On Thu, 2006-08-10 at 19:36 +0900, Fernando Luis Vázquez Cao wrote:
> A kprobe executes IRET early and that could cause NMI recursion and stack
> corruption.
>
> Note: This problem was originally identified and solved by Andi Kleen in the
> x86_64 architecture. This patch is an adaption of his patch for i386.
>
> Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp>
> ---
>
> diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/entry.S linux-2.6.18-rc4/arch/i386/kernel/entry.S
> --- linux-2.6.18-rc4-orig/arch/i386/kernel/entry.S 2006-08-10 17:24:14.000000000 +0900
> +++ linux-2.6.18-rc4/arch/i386/kernel/entry.S 2006-08-10 17:31:55.000000000 +0900
> @@ -725,7 +725,7 @@ debug_stack_correct:
> * check whether we got an NMI on the debug path where the debug
> * fault happened on the sysenter path.
> */
> -ENTRY(nmi)
> +KPROBE_ENTRY(nmi)
> RING0_INT_FRAME
> pushl %eax
> CFI_ADJUST_CFA_OFFSET 4
> diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/nmi.c linux-2.6.18-rc4/arch/i386/kernel/nmi.c
> --- linux-2.6.18-rc4-orig/arch/i386/kernel/nmi.c 2006-08-10 17:24:15.000000000 +0900
> +++ linux-2.6.18-rc4/arch/i386/kernel/nmi.c 2006-08-10 17:40:22.000000000 +0900
> @@ -579,7 +579,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog);
>
> extern void die_nmi(struct pt_regs *, const char *msg);
>
> -void nmi_watchdog_tick (struct pt_regs * regs)
> +void __kprobes nmi_watchdog_tick (struct pt_regs * regs)
> {
>
> /*
> diff -urNp linux-2.6.18-rc4-orig/arch/i386/kernel/traps.c linux-2.6.18-rc4/arch/i386/kernel/traps.c
> --- linux-2.6.18-rc4-orig/arch/i386/kernel/traps.c 2006-08-10 17:24:16.000000000 +0900
> +++ linux-2.6.18-rc4/arch/i386/kernel/traps.c 2006-08-10 18:16:12.000000000 +0900
> @@ -626,7 +626,8 @@ gp_in_kernel:
> }
> }
>
> -static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
> +static __kprobes void
> +mem_parity_error(unsigned char reason, struct pt_regs * regs)
> {
> printk(KERN_EMERG "Uhhuh. NMI received. Dazed and confused, but trying "
> "to continue\n");
> @@ -637,7 +638,8 @@ static void mem_parity_error(unsigned ch
> clear_mem_error(reason);
> }
>
> -static void io_check_error(unsigned char reason, struct pt_regs * regs)
> +static __kprobes void
> +io_check_error(unsigned char reason, struct pt_regs * regs)
> {
> unsigned long i;
>
> @@ -653,7 +655,8 @@ static void io_check_error(unsigned char
> outb(reason, 0x61);
> }
>
> -static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
> +static __kprobes void
> +unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
> {
> #ifdef CONFIG_MCA
> /* Might actually be able to figure out what the guilty party
> @@ -671,7 +674,7 @@ static void unknown_nmi_error(unsigned c
>
> static DEFINE_SPINLOCK(nmi_print_lock);
>
> -void die_nmi (struct pt_regs *regs, const char *msg)
> +void __kprobes die_nmi(struct pt_regs *regs, const char *msg)
> {
> if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) ==
> NOTIFY_STOP)
> @@ -703,7 +706,7 @@ void die_nmi (struct pt_regs *regs, cons
> do_exit(SIGSEGV);
> }
>
> -static void default_do_nmi(struct pt_regs * regs)
> +static __kprobes void default_do_nmi(struct pt_regs * regs)
> {
> unsigned char reason = 0;
>
> @@ -741,14 +744,14 @@ static void default_do_nmi(struct pt_reg
> reassert_nmi();
> }
>
> -static int dummy_nmi_callback(struct pt_regs * regs, int cpu)
> +static __kprobes int dummy_nmi_callback(struct pt_regs * regs, int cpu)
> {
> return 0;
> }
>
> static nmi_callback_t nmi_callback = dummy_nmi_callback;
>
> -fastcall void do_nmi(struct pt_regs * regs, long error_code)
> +fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code)
> {
> int cpu;
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
prev parent reply other threads:[~2006-08-10 10:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-10 10:36 [PATCH 1/2] i386: Disallow kprobes on NMI handlers Fernando Luis Vázquez Cao
2006-08-10 10:40 ` Fernando Luis Vázquez Cao [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1155206455.4141.2.camel@localhost.localdomain \
--to=fernando@oss.ntt.co.jp \
--cc=ak@suse.de \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=prasanna@in.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox