From: Steven Rostedt <rostedt@goodmis.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com,
torvalds@linux-foundation.org, tglx@linutronix.de,
mingo@kernel.org, namit@vmware.com, hpa@zytor.com,
luto@kernel.org, ard.biesheuvel@linaro.org, jpoimboe@redhat.com
Subject: Re: [PATCH v3 5/6] x86/ftrace: Use text_poke()
Date: Wed, 9 Oct 2019 22:41:35 -0400 [thread overview]
Message-ID: <20191009224135.2dcf7767@oasis.local.home> (raw)
In-Reply-To: <20191008104335.6fcd78c9@gandalf.local.home>
On Tue, 8 Oct 2019 10:43:35 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> BTW, I'd really like to take this patch series through my tree. That
> way I can really hammer it, as well as I have code that will be built
> on top of it.
I did a bit of hammering and found two bugs. One I sent a patch to fix
(adding a module when tracing is enabled), but the other bug I
triggered, I'm too tired to debug right now. But figured I'd mention it
anyway.
If you add on the kernel command line:
ftrace=function ftrace_filter=schedule
You will get this (note, I had KASAN enabled, so it showed more info):
[ 1.274356] ftrace: allocating 34274 entries in 134 pages
[ 1.320059] Starting tracer 'function'
[ 1.323724] ==================================================================
[ 1.330798] BUG: KASAN: null-ptr-deref in __get_locked_pte+0x21/0x210
[ 1.337186] Read of size 8 at addr 0000000000000050 by task swapper/0
[ 1.343579]
[ 1.345049] CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-rc2-test+ #50
[ 1.351613] Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
[ 1.360510] Call Trace:
[ 1.362932] dump_stack+0x7c/0xc0
[ 1.366213] ? __get_locked_pte+0x21/0x210
[ 1.370272] ? __get_locked_pte+0x21/0x210
[ 1.374331] __kasan_report.cold.10+0x5/0x3e
[ 1.378566] ? __get_locked_pte+0x21/0x210
[ 1.382625] kasan_report+0xe/0x20
[ 1.385993] __get_locked_pte+0x21/0x210
[ 1.389880] ? 0xffffffffa000005c
[ 1.393162] __text_poke+0x1ca/0x5b0
[ 1.396705] ? optimize_nops.isra.8+0xd0/0xd0
[ 1.401023] ? insn_get_length+0x4f/0x70
[ 1.404910] ? text_poke_loc_init+0x186/0x220
[ 1.409229] ? text_poke_kgdb+0x10/0x10
[ 1.413031] ? 0xffffffffa0000000
[ 1.416312] text_poke_bp_batch+0xb4/0x1e0
[ 1.420372] ? __text_poke+0x5b0/0x5b0
[ 1.424088] ? do_raw_spin_lock+0x113/0x1d0
[ 1.428233] ? 0xffffffffa000005c
[ 1.431515] ? 0xffffffffa0000000
[ 1.434797] text_poke_bp+0x7a/0xa0
[ 1.438253] ? text_poke_queue+0xb0/0xb0
[ 1.442139] ? 0xffffffffa0000000
[ 1.445421] ? 0xffffffffa000005c
[ 1.448706] ? find_vmap_area+0x56/0x80
[ 1.452505] arch_ftrace_update_trampoline+0x114/0x380
[ 1.457603] ? ftrace_caller+0x4e/0x4e
[ 1.461316] ? 0xffffffffa0000091
[ 1.464599] ? arch_ftrace_update_code+0x10/0x10
[ 1.469179] ? mutex_lock+0x86/0xd0
[ 1.472634] ? __mutex_lock_slowpath+0x10/0x10
[ 1.477039] ? mutex_unlock+0x1d/0x40
[ 1.480668] ? arch_jump_label_transform_queue+0x7a/0x90
[ 1.485937] ? __jump_label_update+0x91/0x140
[ 1.490256] ? mutex_unlock+0x1d/0x40
[ 1.493885] ? tracing_start_sched_switch.cold.0+0x60/0x60
[ 1.499327] __register_ftrace_function+0xaf/0xf0
[ 1.503991] ftrace_startup+0x24/0x130
[ 1.507706] register_ftrace_function+0x2d/0x80
[ 1.512198] function_trace_init+0xc1/0x100
[ 1.516346] tracing_set_tracer+0x1fb/0x3c0
[ 1.520492] ? free_snapshot+0x50/0x50
[ 1.524205] ? __kasan_kmalloc.constprop.6+0xc1/0xd0
[ 1.529131] ? __list_add_valid+0x29/0xa0
[ 1.533106] register_tracer+0x235/0x26c
[ 1.536993] early_trace_init+0x29b/0x3a0
[ 1.540967] start_kernel+0x2a3/0x5f7
[ 1.544595] ? mem_encrypt_init+0x6/0x6
[ 1.548396] ? load_ucode_intel_bsp+0x5e/0xa3
[ 1.552715] ? init_intel_microcode+0xc3/0xc3
[ 1.557036] ? load_ucode_bsp+0xcc/0x154
[ 1.560923] secondary_startup_64+0xa4/0xb0
[ 1.565070] ==================================================================
-- Steve
next prev parent reply other threads:[~2019-10-10 2:41 UTC|newest]
Thread overview: 128+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 9:02 [RESEND] everything text-poke: ftrace, modules, static_call and jump_label Peter Zijlstra
2019-10-07 8:17 ` [PATCH v3 0/6] Rewrite x86/ftrace to use text_poke() Peter Zijlstra
2019-10-07 8:17 ` [PATCH v3 1/6] x86/alternatives: Teach text_poke_bp() to emulate instructions Peter Zijlstra
2019-10-08 14:29 ` Borislav Petkov
2019-10-08 14:40 ` Steven Rostedt
2019-10-08 14:50 ` Borislav Petkov
2019-10-08 14:48 ` Peter Zijlstra
2019-10-08 14:54 ` Borislav Petkov
2019-10-08 15:04 ` Steven Rostedt
2019-10-08 15:24 ` Borislav Petkov
2019-10-09 12:03 ` Daniel Bristot de Oliveira
2019-10-07 8:17 ` [PATCH v3 2/6] x86/alternatives: Update int3_emulate_push() comment Peter Zijlstra
2019-10-07 8:17 ` [PATCH v3 3/6] x86/alternatives,jump_label: Provide better text_poke() batching interface Peter Zijlstra
2019-10-09 12:04 ` Daniel Bristot de Oliveira
2019-10-07 8:17 ` [PATCH v3 4/6] x86/alternatives: Add and use text_gen_insn() helper Peter Zijlstra
2019-10-08 6:23 ` Masami Hiramatsu
2019-10-08 8:15 ` Peter Zijlstra
2019-10-07 8:17 ` [PATCH v3 5/6] x86/ftrace: Use text_poke() Peter Zijlstra
2019-10-08 14:43 ` Steven Rostedt
2019-10-08 17:11 ` Peter Zijlstra
2019-10-08 17:27 ` Steven Rostedt
2019-10-10 2:41 ` Steven Rostedt [this message]
2019-10-10 9:20 ` Peter Zijlstra
2019-10-10 13:19 ` Steven Rostedt
2019-10-10 14:05 ` Peter Zijlstra
2019-10-10 15:54 ` Steven Rostedt
2019-10-10 17:28 ` Peter Zijlstra
2019-10-10 17:48 ` Steven Rostedt
2019-10-11 10:45 ` Peter Zijlstra
2019-10-11 10:47 ` Peter Zijlstra
2019-10-11 10:50 ` Peter Zijlstra
2019-10-11 12:59 ` Peter Zijlstra
2019-10-11 13:33 ` Steven Rostedt
2019-10-11 13:45 ` Peter Zijlstra
2019-10-15 13:07 ` Jessica Yu
2019-10-15 13:56 ` Peter Zijlstra
2019-10-15 14:11 ` Peter Zijlstra
2019-10-15 14:13 ` Miroslav Benes
2019-10-15 15:06 ` Joe Lawrence
2019-10-15 15:31 ` Jessica Yu
2019-10-15 22:17 ` Joe Lawrence
2019-10-15 22:27 ` Steven Rostedt
2019-10-16 7:42 ` Peter Zijlstra
2019-10-16 10:15 ` Miroslav Benes
2019-10-21 15:05 ` Josh Poimboeuf
2020-01-20 16:50 ` Josh Poimboeuf
2020-01-21 8:35 ` Miroslav Benes
2020-01-21 16:10 ` Josh Poimboeuf
2020-01-22 10:09 ` Miroslav Benes
2020-01-22 21:42 ` Josh Poimboeuf
2020-01-28 9:28 ` Miroslav Benes
2020-01-28 15:00 ` Josh Poimboeuf
2020-01-28 15:40 ` Petr Mladek
2020-01-28 17:02 ` Josh Poimboeuf
2020-01-29 0:46 ` Jiri Kosina
2020-01-29 2:17 ` Josh Poimboeuf
2020-01-29 3:14 ` Jiri Kosina
2020-01-29 12:28 ` Miroslav Benes
2020-01-29 15:59 ` Josh Poimboeuf
2020-01-30 9:53 ` Petr Mladek
2020-01-30 14:17 ` Josh Poimboeuf
2020-01-31 7:17 ` Petr Mladek
2020-01-22 12:15 ` Miroslav Benes
2020-01-22 15:05 ` Miroslav Benes
2020-01-22 22:03 ` Josh Poimboeuf
2020-01-23 10:19 ` Martin Jambor
2019-10-16 7:49 ` Peter Zijlstra
2019-10-16 10:20 ` Miroslav Benes
2019-10-16 13:29 ` Miroslav Benes
2019-10-18 13:03 ` Jessica Yu
2019-10-18 13:40 ` Petr Mladek
2019-10-21 14:14 ` Jessica Yu
2019-10-21 15:31 ` Josh Poimboeuf
2019-10-22 8:27 ` Miroslav Benes
2019-10-22 14:31 ` Josh Poimboeuf
2019-10-23 9:04 ` Miroslav Benes
2019-10-16 6:51 ` Miroslav Benes
2019-10-16 9:23 ` Peter Zijlstra
2019-10-16 9:36 ` Jessica Yu
2019-10-16 9:51 ` Peter Zijlstra
2019-10-16 12:39 ` Peter Zijlstra
2019-10-22 8:45 ` Miroslav Benes
2019-10-15 14:42 ` Peter Zijlstra
2019-10-15 18:31 ` Peter Zijlstra
2019-10-15 15:51 ` Jessica Yu
2019-10-15 13:28 ` Steven Rostedt
2019-10-15 13:42 ` Peter Zijlstra
2019-10-15 16:09 ` Jessica Yu
2019-10-07 8:17 ` [PATCH v3 6/6] x86/mm: Remove set_kernel_text_r[ow]() Peter Zijlstra
2019-10-08 15:07 ` [PATCH v3 0/6] Rewrite x86/ftrace to use text_poke() Steven Rostedt
2019-10-07 8:25 ` [PATCH v2 0/4] Propagate module notifier errors Peter Zijlstra
2019-10-07 8:25 ` [PATCH v2 1/4] notifier: Fix broken error handling pattern Peter Zijlstra
2019-10-10 22:01 ` Rafael J. Wysocki
2019-10-07 8:25 ` [PATCH v2 2/4] module: Fix up module_notifier return values Peter Zijlstra
2019-10-23 19:25 ` Steven Rostedt
2019-10-07 8:25 ` [PATCH v2 3/4] module: Properly propagate MODULE_STATE_COMING failure Peter Zijlstra
2019-10-08 13:08 ` Miroslav Benes
2019-10-07 8:25 ` [PATCH v2 4/4] jump_label,module: Fix module lifetime for __jump_label_mod_text_reserved Peter Zijlstra
2019-10-23 19:29 ` Steven Rostedt
2019-10-07 8:27 ` [PATCH v2 00/13] Add static_call() Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 01/13] compiler.h: Make __ADDRESSABLE() symbol truly unique Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 02/13] static_call: Add basic static call infrastructure Peter Zijlstra
2019-10-07 11:33 ` Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 03/13] static_call: Add inline " Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 04/13] static_call: Avoid kprobes on inline static_call()s Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 05/13] x86/static_call: Add out-of-line static call implementation Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 06/13] x86/static_call: Add inline static call implementation for x86-64 Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 07/13] static_call: Simple self-test Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 08/13] tracepoints: Use static_call Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 09/13] x86/alternatives: Teach text_poke_bp() to emulate RET Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 10/13] static_call: Add static_cond_call() Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 11/13] static_call: Handle tail-calls Peter Zijlstra
2019-10-07 8:27 ` [PATCH v2 12/13] static_call: Allow early init Peter Zijlstra
2019-10-07 8:27 ` [RFC][PATCH v2 13/13] x86/perf, static_call: Optimize x86_pmu methods Peter Zijlstra
2019-10-07 11:33 ` [PATCH v2 00/13] Add static_call() Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 0/9] Variable size jump_label support Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 1/9] jump_label, x86: Strip ASM " Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 2/9] jump_label, x86: Factor out the __jump_table generation Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 3/9] jump_label, x86: Remove init NOP optimization Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 4/9] jump_label, x86: Improve error when we fail expected text Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 5/9] jump_label, x86: Introduce jump_entry_size() Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 6/9] jump_label, x86: Add variable length patching support Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 7/9] jump_label,objtool: Validate variable size jump labels Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 8/9] jump_label,objtool: Generate possible statistics Peter Zijlstra
2019-10-07 8:44 ` [RFC][PATCH 9/9] jump_label, x86: Enable JMP8/NOP2 support Peter Zijlstra
2019-10-07 12:07 ` [RFC][PATCH 0/9] Variable size jump_label support Peter Zijlstra
2019-10-07 12:55 ` Ingo Molnar
2019-10-07 15:08 ` Steven Rostedt
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