From: Will Deacon <will@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
rostedt@goodmis.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, jeyu@kernel.org,
alexei.starovoitov@gmail.com, rabin@rab.in,
Mark Rutland <mark.rutland@arm.com>,
james.morse@arm.com
Subject: Re: [PATCH -v5 13/17] arm/ftrace: Use __patch_text_real()
Date: Mon, 11 Nov 2019 16:47:03 +0000 [thread overview]
Message-ID: <20191111164703.GA11521@willie-the-truck> (raw)
In-Reply-To: <20191111132458.220458362@infradead.org>
On Mon, Nov 11, 2019 at 02:13:05PM +0100, Peter Zijlstra wrote:
> Instead of flipping text protection, use the patch_text infrastructure
> that uses a fixmap alias where required.
>
> This removes the last user of set_all_modules_text_*().
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: ard.biesheuvel@linaro.org
> Cc: rabin@rab.in
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: james.morse@arm.com
> ---
> arch/arm/kernel/ftrace.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> --- a/arch/arm/kernel/ftrace.c
> +++ b/arch/arm/kernel/ftrace.c
> @@ -22,6 +22,7 @@
> #include <asm/ftrace.h>
> #include <asm/insn.h>
> #include <asm/set_memory.h>
> +#include <asm/patch.h>
>
> #ifdef CONFIG_THUMB2_KERNEL
> #define NOP 0xf85deb04 /* pop.w {lr} */
> @@ -31,13 +32,15 @@
>
> #ifdef CONFIG_DYNAMIC_FTRACE
>
> +static int patch_text_remap = 0;
> +
> static int __ftrace_modify_code(void *data)
> {
> int *command = data;
>
> - set_kernel_text_rw();
> + patch_text_remap++;
> ftrace_modify_all_code(*command);
> - set_kernel_text_ro();
> + patch_text_remap--;
>
> return 0;
> }
> @@ -59,13 +62,13 @@ static unsigned long adjust_address(stru
>
> int ftrace_arch_code_modify_prepare(void)
> {
> - set_all_modules_text_rw();
> + patch_text_remap++;
> return 0;
> }
>
> int ftrace_arch_code_modify_post_process(void)
> {
> - set_all_modules_text_ro();
> + patch_text_remap--;
> /* Make sure any TLB misses during machine stop are cleared. */
> flush_tlb_all();
> return 0;
> @@ -97,10 +100,7 @@ static int ftrace_modify_code(unsigned l
> return -EINVAL;
> }
>
> - if (probe_kernel_write((void *)pc, &new, MCOUNT_INSN_SIZE))
> - return -EPERM;
> -
> - flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
> + __patch_text_real((void *)pc, new, patch_text_remap);
I'd still prefer to pass 'true' unconditionally here, since I don't think
this is a hot path.
Will
next prev parent reply other threads:[~2019-11-11 16:47 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-11 13:12 [PATCH -v5 00/17] Rewrite x86/ftrace to use text_poke (and more) Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 01/17] x86/alternatives: Teach text_poke_bp() to emulate instructions Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 02/17] x86/alternatives: Update int3_emulate_push() comment Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 03/17] x86/alternatives,jump_label: Provide better text_poke() batching interface Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] x86/alternatives, jump_label: " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 04/17] x86/alternatives: Add and use text_gen_insn() helper Peter Zijlstra
2019-11-12 17:10 ` Steven Rostedt
2019-11-12 22:25 ` Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 05/17] x86/ftrace: Use text_poke() Peter Zijlstra
2019-11-12 18:25 ` Steven Rostedt
2019-11-12 22:24 ` Peter Zijlstra
2019-11-12 22:48 ` Steven Rostedt
2019-11-13 9:01 ` Peter Zijlstra
2019-11-13 14:27 ` Steven Rostedt
2019-11-14 13:18 ` Peter Zijlstra
2019-11-14 13:56 ` Steven Rostedt
2019-11-14 14:05 ` Peter Zijlstra
2019-11-13 8:53 ` Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-11-16 20:46 ` Borislav Petkov
2019-11-18 17:35 ` [PATCH] x86/ftrace: Mark ftrace_modify_code_direct() __ref Borislav Petkov
2019-11-18 17:52 ` Steven Rostedt
2019-11-19 9:55 ` [tip: core/kprobes] " tip-bot2 for Borislav Petkov
2019-12-04 8:33 ` tip-bot2 for Borislav Petkov
2019-12-04 8:33 ` [tip: core/kprobes] x86/ftrace: Use text_poke() tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 06/17] x86/mm: Remove set_kernel_text_r[ow]() Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:12 ` [PATCH -v5 07/17] x86/alternative: Add text_opcode_size() Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 08/17] x86/ftrace: Use text_gen_insn() Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 09/17] x86/alternative: Remove text_poke_loc::len Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 10/17] x86/alternative: Shrink text_poke_loc Peter Zijlstra
2019-11-15 9:43 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 11/17] x86/kprobes: Convert to text-patching.h Peter Zijlstra
2019-11-19 16:56 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 12/17] x86/kprobes: Fix ordering Peter Zijlstra
2019-11-13 14:31 ` Paul E. McKenney
2019-11-13 15:42 ` Mathieu Desnoyers
2019-11-14 13:53 ` Peter Zijlstra
2019-11-14 15:06 ` Mathieu Desnoyers
2019-11-14 15:13 ` Paul E. McKenney
2019-11-14 15:22 ` Mathieu Desnoyers
2019-11-14 15:28 ` Peter Zijlstra
2019-11-14 15:30 ` Mathieu Desnoyers
2019-11-14 15:42 ` Peter Zijlstra
2019-11-14 15:58 ` Peter Zijlstra
2019-11-19 16:56 ` [tip: core/kprobes] x86/kprobes: Fix ordering while text-patching tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 13/17] arm/ftrace: Use __patch_text_real() Peter Zijlstra
2019-11-11 16:47 ` Will Deacon [this message]
2019-11-11 17:19 ` Peter Zijlstra
2019-11-11 17:25 ` Peter Zijlstra
2019-11-12 11:29 ` Will Deacon
2019-11-13 9:26 ` [PATCH -v5mkII 13/17] arm/ftrace: Use __patch_text() Peter Zijlstra
2019-11-19 16:56 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2020-01-22 21:26 ` Dmitry Osipenko
2020-02-07 10:17 ` Peter Zijlstra
2020-02-07 10:26 ` Peter Zijlstra
2020-02-07 11:27 ` Peter Zijlstra
2020-02-07 16:47 ` Dmitry Osipenko
2020-01-08 12:22 ` [PATCH -v5mkII 13/17] " Arnd Bergmann
2020-01-08 14:16 ` Steven Rostedt
2020-01-08 14:22 ` Arnd Bergmann
2019-11-11 13:13 ` [PATCH -v5 14/17] module: Remove set_all_modules_text_*() Peter Zijlstra
2019-11-19 16:56 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 15/17] ftrace: Rework event_create_dir() Peter Zijlstra
2019-11-14 14:07 ` Steven Rostedt
2019-11-19 16:56 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 16/17] x86/kprobe: Add comments to arch_{,un}optimize_kprobes() Peter Zijlstra
2019-11-19 16:56 ` [tip: core/kprobes] " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 13:13 ` [PATCH -v5 17/17] x86/alternative: Use INT3_INSN_SIZE Peter Zijlstra
2019-11-19 16:56 ` [tip: core/kprobes] x86/alternatives: " tip-bot2 for Peter Zijlstra
2019-12-04 8:33 ` tip-bot2 for Peter Zijlstra
2019-11-11 19:47 ` [PATCH -v5 00/17] Rewrite x86/ftrace to use text_poke (and more) Alexei Starovoitov
2019-11-11 20:39 ` Peter Zijlstra
2019-11-11 20:42 ` Peter Zijlstra
2019-11-11 20:56 ` Alexei Starovoitov
2019-11-12 18:26 ` Steven Rostedt
2019-11-25 3:55 ` Masami Hiramatsu
2019-11-25 6:47 ` Masami Hiramatsu
2019-11-25 17:32 ` Steven Rostedt
2019-11-26 0:11 ` Masami Hiramatsu
2019-11-26 8:58 ` Masami Hiramatsu
2019-11-26 9:58 ` Masami Hiramatsu
2019-11-26 23:48 ` Masami Hiramatsu
[not found] ` <CAADnVQK4twuXzFhD-qLHmCVK0n1h-GDENQLu+4PVV3Hp++R6kQ@mail.gmail.com>
2019-11-27 4:32 ` Alexei Starovoitov
2019-11-27 5:01 ` Alexei Starovoitov
2019-11-27 6:41 ` Masami Hiramatsu
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=20191111164703.GA11521@willie-the-truck \
--to=will@kernel.org \
--cc=alexei.starovoitov@gmail.com \
--cc=ard.biesheuvel@linaro.org \
--cc=bristot@redhat.com \
--cc=hpa@zytor.com \
--cc=james.morse@arm.com \
--cc=jbaron@akamai.com \
--cc=jeyu@kernel.org \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=namit@vmware.com \
--cc=peterz@infradead.org \
--cc=rabin@rab.in \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).