From: "Suzuki K. Poulose" <suzuki@in.ibm.com>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Tony Luck <tony.luck@gmail.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>,
linux-ia64@vger.kernel.org, sparse@chrisli.org,
"H. Peter Anvin" <hpa@zytor.com>,
akataria@vmware.com, linux-tip-commits@vger.kernel.org,
anil.s.keshavamurthy@intel.com, Ingo Molnar <mingo@kernel.org>,
Fenghua Yu <fenghua.yu@intel.com>, Arnd Bergmann <arnd@arndb.de>,
Rusty Russell <rusty@rustcorp.com.au>,
Chris Wright <chrisw@sous-sol.org>,
yrl.pp-manager.tt@hitachi.com,
Thomas Gleixner <tglx@linutronix.de>,
Tony Luck <tony.luck@intel.com>, Kevin Hao <haokexin@gmail.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
rdunlap@infradead.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
dl9pf@gmx.de, Andrew Morton <akpm@linux-foundation.org>,
linuxppc-dev@lists.ozlabs.org,
"David S. Miller" <davem@davemloft.net>
Subject: Re: [RFT PATCH -next v2] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64
Date: Fri, 30 May 2014 00:43:28 +0530 [thread overview]
Message-ID: <538786D8.1070303@in.ibm.com> (raw)
In-Reply-To: <20140527063121.4399.38014.stgit@ltc230.yrl.intra.hitachi.co.jp>
On 05/27/2014 12:01 PM, Masami Hiramatsu wrote:
> On ia64 and ppc64, the function pointer does not point the
> entry address of the function, but the address of function
> discriptor (which contains the entry address and misc
> data.) Since the kprobes passes the function pointer stored
> by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
> initalizing its blacklist, it fails and reports many errors
> as below.
>
> Failed to find blacklist 0001013168300000
> Failed to find blacklist 0001013000f0a000
> Failed to find blacklist 000101315f70a000
> Failed to find blacklist 000101324c80a000
> Failed to find blacklist 0001013063f0a000
> Failed to find blacklist 000101327800a000
> Failed to find blacklist 0001013277f0a000
> Failed to find blacklist 000101315a70a000
> Failed to find blacklist 0001013277e0a000
> Failed to find blacklist 000101305a20a000
> Failed to find blacklist 0001013277d0a000
> Failed to find blacklist 00010130bdc0a000
> Failed to find blacklist 00010130dc20a000
> Failed to find blacklist 000101309a00a000
> Failed to find blacklist 0001013277c0a000
> Failed to find blacklist 0001013277b0a000
> Failed to find blacklist 0001013277a0a000
> Failed to find blacklist 000101327790a000
> Failed to find blacklist 000101303140a000
> Failed to find blacklist 0001013a3280a000
>
> To fix this bug, this introduces function_entry() macro to
> retrieve the entry address from the given function pointer,
> and uses for kallsyms_lookup_size_offset() while initializing
> blacklist.
>
> Changes in V2:
> - Use function_entry() macro when lookin up symbols instead
> of storing it.
> - Update for the latest -next.
>
> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Reported-by: Tony Luck <tony.luck@gmail.com>
> Cc: Suzuki K. Poulose <suzuki@in.ibm.com>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Cc: Kevin Hao <haokexin@gmail.com>
> Cc: linux-ia64@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> ---
> arch/ia64/include/asm/types.h | 2 ++
> arch/powerpc/include/asm/types.h | 11 +++++++++++
> include/linux/types.h | 4 ++++
> kernel/kprobes.c | 4 +++-
> 4 files changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/arch/ia64/include/asm/types.h b/arch/ia64/include/asm/types.h
> index 4c351b1..95279dd 100644
> --- a/arch/ia64/include/asm/types.h
> +++ b/arch/ia64/include/asm/types.h
> @@ -27,5 +27,7 @@ struct fnptr {
> unsigned long gp;
> };
>
> +#define function_entry(fn) (((struct fnptr *)(fn))->ip)
> +
> #endif /* !__ASSEMBLY__ */
> #endif /* _ASM_IA64_TYPES_H */
> diff --git a/arch/powerpc/include/asm/types.h b/arch/powerpc/include/asm/types.h
> index bfb6ded..8b89d65 100644
> --- a/arch/powerpc/include/asm/types.h
> +++ b/arch/powerpc/include/asm/types.h
> @@ -25,6 +25,17 @@ typedef struct {
> unsigned long env;
> } func_descr_t;
>
> +#if defined(CONFIG_PPC64) && (!defined(_CALL_ELF) || _CALL_ELF == 1)
> +/*
> + * On PPC64 ABIv1 the function pointer actually points to the
> + * function's descriptor. The first entry in the descriptor is the
> + * address of the function text.
> + */
> +#define function_entry(fn) (((func_descr_t *)(fn))->entry)
> +#else
> +#define function_entry(fn) ((unsigned long)(fn))
> +#endif
> +
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_POWERPC_TYPES_H */
> diff --git a/include/linux/types.h b/include/linux/types.h
> index a0bb704..3b95369 100644
> --- a/include/linux/types.h
> +++ b/include/linux/types.h
> @@ -213,5 +213,9 @@ struct callback_head {
> };
> #define rcu_head callback_head
>
> +#ifndef function_entry
> +#define function_entry(fn) ((unsigned long)(fn))
> +#endif
> +
> #endif /* __ASSEMBLY__ */
> #endif /* _LINUX_TYPES_H */
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 2ac9f13..3859c88 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -32,6 +32,7 @@
> * <prasanna@in.ibm.com> added function-return probes.
> */
> #include <linux/kprobes.h>
> +#include <linux/types.h>
> #include <linux/hash.h>
> #include <linux/init.h>
> #include <linux/slab.h>
> @@ -2042,7 +2043,8 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
> unsigned long offset = 0, size = 0;
>
> for (iter = start; iter < end; iter++) {
> - if (!kallsyms_lookup_size_offset(*iter, &size, &offset)) {
> + if (!kallsyms_lookup_size_offset(function_entry(*iter),
> + &size, &offset)) {
On powerpc we will be able to resolve the *iter to func_descr and won't
get the below error with/without this patch. So we have to actually
verify the kprobe_blacklist contents to make sure everything is alright.
> pr_err("Failed to find blacklist %p\n", (void *)*iter);
> continue;
> }
>
There is a bug here.
You need to set the ent->start using the function_entry(*iter) and not
*iter. Or else you just avoid the 'Warning' and still have an invalid
black list. As shown below :
2e:mon> ls kprobe_blacklist
kprobe_blacklist: c00000000104dad0
2e:mon> d c00000000104dad0 10
c00000000104dad0: c0000003aff800a0 c0000003aff809a0
2e:mon> d c0000003aff800a0 20 (struct kprobe_blacklist *)
c0000003aff800a0: c0000003aff800c0 c00000000104dad0
c0000003aff800b0: c0000000010ef138 c0000000010ef188
start ^^ end ^^
2e:mon> la c0000000010ef138 (start)
c0000000010ef138: notify_die+0x0/0x10 <- still points to the
function descriptor
2e:mon> la c0000000010ef188 (end)
c0000000010ef188: __blocking_notifier_call_chain+0x0/0x10
Following patch fixes the issue, with the patch :
1:mon> ls kprobe_blacklist
kprobe_blacklist: c00000000104dad0
1:mon> d c00000000104dad0 10
c00000000104dad0: c0000003ae1a00a0 c0000003ae1a09a0
1:mon> d c0000003ae1a00a0 20 (struct kprobe_blacklist *)
c0000003ae1a00a0: c0000003ae1a00c0 c00000000104dad0
c0000003ae1a00b0: c0000000000b14d0 c0000000000b1520
start ^^ end ^^
1:mon> la c0000000000b14d0
c0000000000b14d0: .notify_die+0x0/0x50
1:mon> la c0000000000b1520
c0000000000b1520: .atomic_notifier_chain_register+0x0/0xa0
1:mon> di c0000000000b14d0 10 (.notify_die)
c0000000000b14d0 7c0802a6 mflr r0
c0000000000b14d4 7c691b78 mr r9,r3
commit ed51674aca8e0496641f565421ab6691a873e80a
Author: Suzuki K. Poulose <suzuki@in.ibm.com>
Date: Fri May 30 00:23:01 2014 +0530
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3859c88..b81d626 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2043,7 +2043,8 @@ static int __init
populate_kprobe_blacklist(unsigned long *start,
unsigned long offset = 0, size = 0;
for (iter = start; iter < end; iter++) {
- if (!kallsyms_lookup_size_offset(function_entry(*iter),
+ unsigned long entry = function_entry(*iter);
+ if (!kallsyms_lookup_size_offset(entry,
&size, &offset)) {
pr_err("Failed to find blacklist %p\n", (void
*)*iter);
continue;
@@ -2052,8 +2053,8 @@ static int __init
populate_kprobe_blacklist(unsigned long *start,
ent = kmalloc(sizeof(*ent), GFP_KERNEL);
if (!ent)
return -ENOMEM;
- ent->start_addr = *iter;
- ent->end_addr = *iter + size;
+ ent->start_addr = entry;
+ ent->end_addr = entry + size;
INIT_LIST_HEAD(&ent->list);
list_add_tail(&ent->list, &kprobe_blacklist);
}
Thanks
Suzuki
next prev parent reply other threads:[~2014-05-29 19:13 UTC|newest]
Thread overview: 103+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-17 8:16 [PATCH -tip v9 00/26] kprobes: introduce NOKPROBE_SYMBOL, bugfixes and scalbility efforts Masami Hiramatsu
2014-04-17 8:16 ` [PATCH -tip v9 01/26] [BUGFIX]kprobes/x86: Fix page-fault handling logic Masami Hiramatsu
2014-04-17 9:58 ` [tip:perf/urgent] kprobes/x86: " tip-bot for Masami Hiramatsu
2014-04-17 8:16 ` [PATCH -tip v9 02/26] kprobes/x86: Allow to handle reentered kprobe on singlestepping Masami Hiramatsu
2014-04-24 10:57 ` [tip:perf/kprobes] kprobes/x86: Allow to handle reentered kprobe on single-stepping tip-bot for Masami Hiramatsu
2014-04-17 8:16 ` [PATCH -tip v9 03/26] kprobes: Prohibit probing on .entry.text code Masami Hiramatsu
2014-04-24 10:57 ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17 8:17 ` [PATCH -tip v9 04/26] kprobes: Introduce NOKPROBE_SYMBOL() macro for blacklist Masami Hiramatsu
2014-04-24 10:58 ` [tip:perf/kprobes] kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist tip-bot for Masami Hiramatsu
2014-05-01 5:26 ` kprobes broken in linux-next (was Re: [tip:perf/kprobes] kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist) Vineet Gupta
2014-05-02 1:13 ` Masami Hiramatsu
2014-05-07 4:56 ` Vineet Gupta
2014-05-07 19:18 ` [tip:perf/kprobes] kprobes: Ensure blacklist data is aligned tip-bot for Vineet Gupta
2014-05-05 20:48 ` [tip:perf/kprobes] kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist Tony Luck
2014-05-06 9:25 ` Masami Hiramatsu
2014-05-06 10:03 ` Masami Hiramatsu
2014-05-07 11:19 ` Masami Hiramatsu
2014-05-07 11:55 ` [RFT PATCH -next ] [BUGFIX] kprobes: Fix "Failed to find blacklist" error on ia64 and ppc64 Masami Hiramatsu
2014-05-07 11:59 ` Masami Hiramatsu
2014-05-14 8:19 ` Masami Hiramatsu
2014-05-08 4:47 ` Ananth N Mavinakayanahalli
2014-05-08 5:40 ` Masami Hiramatsu
2014-05-08 6:16 ` Ananth N Mavinakayanahalli
2014-05-09 8:06 ` Masami Hiramatsu
2014-05-26 11:25 ` Suzuki K. Poulose
2014-05-26 11:48 ` Masami Hiramatsu
2014-05-27 6:31 ` [RFT PATCH -next v2] " Masami Hiramatsu
2014-05-29 19:13 ` Suzuki K. Poulose [this message]
2014-05-30 2:47 ` Masami Hiramatsu
2014-05-30 3:18 ` [RFT PATCH -next v3] " Masami Hiramatsu
2014-06-06 6:38 ` Masami Hiramatsu
2014-06-17 23:03 ` Tony Luck
2014-06-18 7:56 ` Michael Ellerman
2014-06-18 8:46 ` Masami Hiramatsu
2014-06-19 1:30 ` Michael Ellerman
2014-06-19 4:52 ` Masami Hiramatsu
2014-06-19 6:40 ` Suzuki K. Poulose
2014-06-19 7:26 ` Masami Hiramatsu
2014-06-19 9:45 ` Suzuki K. Poulose
2014-06-19 11:01 ` Masami Hiramatsu
2014-06-19 11:20 ` Masami Hiramatsu
2014-06-20 0:37 ` Michael Ellerman
2014-06-20 2:13 ` Masami Hiramatsu
2014-04-17 8:17 ` [PATCH -tip v9 05/26] [BUGFIX] kprobes/x86: Prohibit probing on debug_stack_* Masami Hiramatsu
2014-04-24 10:58 ` [tip:perf/kprobes] kprobes, x86: Prohibit probing on debug_stack_*() tip-bot for Masami Hiramatsu
2014-04-17 8:17 ` [PATCH -tip v9 06/26] [BUGFIX] x86: Prohibit probing on native_set_debugreg/load_idt Masami Hiramatsu
2014-04-24 10:58 ` [tip:perf/kprobes] kprobes, x86: Prohibit probing on native_set_debugreg()/load_idt() tip-bot for Masami Hiramatsu
2014-04-17 8:17 ` [PATCH -tip v9 07/26] [BUGFIX] x86: Prohibit probing on thunk functions and restore Masami Hiramatsu
2014-04-24 10:58 ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17 8:17 ` [PATCH -tip v9 08/26] kprobes/x86: Call exception handlers directly from do_int3/do_debug Masami Hiramatsu
2014-04-24 10:59 ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-24 11:26 ` Jiri Kosina
2014-04-17 8:17 ` [PATCH -tip v9 09/26] x86: Call exception_enter after kprobes handled Masami Hiramatsu
2014-04-24 10:59 ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-06-13 17:14 ` Frederic Weisbecker
2014-06-14 5:44 ` Masami Hiramatsu
2014-06-14 6:47 ` [PATCH -tip ] [Bugfix] x86/kprobes: Fix build errors and blacklist context_track_user Masami Hiramatsu
2014-06-14 8:58 ` [tip:perf/urgent] " tip-bot for Masami Hiramatsu
2014-06-16 15:52 ` [PATCH -tip ] [Bugfix] " Frederic Weisbecker
2014-04-17 8:17 ` [PATCH -tip v9 10/26] kprobes/x86: Allow probe on some kprobe preparation functions Masami Hiramatsu
2014-04-24 10:59 ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17 8:17 ` [PATCH -tip v9 11/26] kprobes: Allow probe on some kprobe functions Masami Hiramatsu
2014-04-24 10:59 ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 12/26] ftrace/*probes: Allow probing on some functions Masami Hiramatsu
2014-04-24 10:59 ` [tip:perf/kprobes] kprobes, ftrace: " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 13/26] x86: Allow kprobes on text_poke/hw_breakpoint Masami Hiramatsu
2014-04-24 11:00 ` [tip:perf/kprobes] kprobes, x86: Allow kprobes on text_poke/ hw_breakpoint tip-bot for Masami Hiramatsu
2014-04-24 11:26 ` Jiri Kosina
2014-04-17 8:18 ` [PATCH -tip v9 14/26] x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation Masami Hiramatsu
2014-04-24 11:00 ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 15/26] kprobes: Use NOKPROBE_SYMBOL macro instead of __kprobes Masami Hiramatsu
2014-04-24 11:00 ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 16/26] ftrace/kprobes: Use NOKPROBE_SYMBOL macro in ftrace Masami Hiramatsu
2014-04-24 11:00 ` [tip:perf/kprobes] kprobes, ftrace: " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 17/26] notifier: Use NOKPROBE_SYMBOL macro in notifier Masami Hiramatsu
2014-04-17 14:40 ` Josh Triplett
2014-04-24 11:00 ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 18/26] sched: Use NOKPROBE_SYMBOL macro in sched Masami Hiramatsu
2014-04-24 11:01 ` [tip:perf/kprobes] kprobes, " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 19/26] kprobes: Show blacklist entries via debugfs Masami Hiramatsu
2014-04-24 11:01 ` [tip:perf/kprobes] " tip-bot for Masami Hiramatsu
2014-04-17 8:18 ` [PATCH -tip v9 20/26] kprobes: Support blacklist functions in module Masami Hiramatsu
2014-04-24 8:56 ` Ingo Molnar
2014-04-24 11:24 ` Masami Hiramatsu
2014-04-25 8:19 ` Ingo Molnar
2014-04-25 10:12 ` Masami Hiramatsu
2014-04-25 10:55 ` Masami Hiramatsu
2014-04-17 8:19 ` [PATCH -tip v9 21/26] kprobes: Use NOKPROBE_SYMBOL() in sample modules Masami Hiramatsu
2014-04-17 8:19 ` [PATCH -tip v9 22/26] kprobes/x86: Use kprobe_blacklist for .kprobes.text and .entry.text Masami Hiramatsu
2014-04-24 8:58 ` Ingo Molnar
2014-04-24 11:22 ` Masami Hiramatsu
2014-04-17 8:19 ` [PATCH -tip v9 23/26] kprobes/x86: Remove unneeded preempt_disable/enable in interrupt handlers Masami Hiramatsu
2014-04-17 8:19 ` [PATCH -tip v9 24/26] kprobes: Enlarge hash table to 512 entries Masami Hiramatsu
2014-04-17 8:19 ` [PATCH -tip v9 25/26] kprobes: Introduce kprobe cache to reduce cache misshits Masami Hiramatsu
2014-04-24 9:01 ` Ingo Molnar
2014-04-24 11:38 ` Masami Hiramatsu
2014-04-25 8:20 ` Ingo Molnar
2014-04-25 9:43 ` Masami Hiramatsu
2014-04-26 7:12 ` Ingo Molnar
2014-04-27 12:49 ` Masami Hiramatsu
2014-04-17 8:19 ` [PATCH -tip v9 26/26] ftrace: Introduce FTRACE_OPS_FL_SELF_FILTER for ftrace-kprobe Masami Hiramatsu
2014-04-17 8:37 ` [PATCH -tip v9 00/26] kprobes: introduce NOKPROBE_SYMBOL, bugfixes and scalbility efforts Ingo Molnar
2014-04-17 8:53 ` Masami Hiramatsu
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