From: Guo Ren <guoren@kernel.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: arnd@arndb.de, palmer@rivosinc.com, tglx@linutronix.de,
luto@kernel.org, conor.dooley@microchip.com, heiko@sntech.de,
jszhang@kernel.org, lazyparser@gmail.com, falcon@tinylab.org,
chenhuacai@kernel.org, apatel@ventanamicro.com,
atishp@atishpatra.org, palmer@dabbelt.com,
paul.walmsley@sifive.com, bigeasy@linutronix.de,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-riscv@lists.infradead.org,
Guo Ren <guoren@linux.alibaba.com>
Subject: Re: [PATCH V4 4/8] riscv: traps: Add noinstr to prevent instrumentation inserted
Date: Sat, 10 Sep 2022 17:17:44 +0800 [thread overview]
Message-ID: <CAJF2gTSs4Ycu52DH6NUzdMXQGMT51XU6x-fgQ-_OpRne+vkTqQ@mail.gmail.com> (raw)
In-Reply-To: <Yxmaz7wJPEBQ7Vki@hirez.programming.kicks-ass.net>
On Thu, Sep 8, 2022 at 3:34 PM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Wed, Sep 07, 2022 at 10:25:02PM -0400, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Without noinstr the compiler is free to insert instrumentation (think
> > all the k*SAN, KCov, GCov, ftrace etc..) which can call code we're not
> > yet ready to run this early in the entry path, for instance it could
> > rely on RCU which isn't on yet, or expect lockdep state. (by peterz)
> >
> > Link: https://lore.kernel.org/linux-riscv/YxcQ6NoPf3AH0EXe@hirez.programming.kicks-ass.net/raw
> > Suggested-by: Peter Zijlstra <peterz@infradead.org>
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > ---
> > arch/riscv/kernel/traps.c | 8 ++++----
> > arch/riscv/mm/fault.c | 2 +-
> > 2 files changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
> > index 635e6ec26938..3ed3dbec250d 100644
> > --- a/arch/riscv/kernel/traps.c
> > +++ b/arch/riscv/kernel/traps.c
> > @@ -97,7 +97,7 @@ static void do_trap_error(struct pt_regs *regs, int signo, int code,
> > #define __trap_section
> > #endif
> > #define DO_ERROR_INFO(name, signo, code, str) \
> > -asmlinkage __visible __trap_section void name(struct pt_regs *regs) \
> > +asmlinkage __visible __trap_section void noinstr name(struct pt_regs *regs) \
>
> But now you have __trap_section and noinstr both adding a section
> attribute.
Oops, thx for correcting. Here is my solution.
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 635e6ec26938..eba744caa711 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -92,9 +92,11 @@ static void do_trap_error(struct pt_regs *regs, int
signo, int code,
}
#if defined(CONFIG_XIP_KERNEL) && defined(CONFIG_RISCV_ALTERNATIVE)
-#define __trap_section __section(".xip.traps")
+#define __trap_section \
+ noinline notrace __attribute((__section__(".xip.traps"))) \
+ __no_kcsan __no_sanitize_address __no_profile __no_sanitize_coverage
#else
-#define __trap_section
+#define __trap_section noinstr
#endif
--
Best Regards
Guo Ren
next prev parent reply other threads:[~2022-09-10 9:19 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-08 2:24 [PATCH V4 0/9] riscv: Add GENERIC_ENTRY, irq stack support guoren
2022-09-08 2:24 ` [PATCH V4 1/8] riscv: elf_kexec: Fixup compile warning guoren
2022-09-08 2:25 ` [PATCH V4 2/8] riscv: compat_syscall_table: " guoren
2022-09-08 2:25 ` [PATCH V4 3/8] riscv: ptrace: Remove duplicate operation guoren
2022-09-08 2:25 ` [PATCH V4 4/8] riscv: traps: Add noinstr to prevent instrumentation inserted guoren
2022-09-08 7:33 ` Peter Zijlstra
2022-09-10 9:17 ` Guo Ren [this message]
2022-09-10 12:46 ` Guo Ren
2022-09-11 15:09 ` Peter Zijlstra
2022-09-11 16:20 ` Guo Ren
2022-09-08 2:25 ` [PATCH V4 5/8] riscv: convert to generic entry guoren
2022-09-15 13:50 ` Yipeng Zou
2022-09-08 2:25 ` [PATCH V4 6/8] riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK guoren
2022-09-08 16:08 ` Sebastian Andrzej Siewior
2022-09-09 7:30 ` David Laight
2022-09-11 1:13 ` Guo Ren
2022-09-08 2:25 ` [PATCH V4 7/8] riscv: Support HAVE_SOFTIRQ_ON_OWN_STACK guoren
2022-09-08 16:01 ` Sebastian Andrzej Siewior
2022-09-18 15:42 ` Guo Ren
2022-09-08 2:25 ` [PATCH V4 8/8] riscv: Add config of thread stack size guoren
2022-09-08 7:35 ` Arnd Bergmann
2022-09-10 12:52 ` Guo Ren
2022-09-10 16:06 ` Arnd Bergmann
2022-09-10 23:35 ` Guo Ren
2022-09-11 18:39 ` Arnd Bergmann
2022-09-12 4:14 ` Guo Ren
2022-09-12 8:23 ` Arnd Bergmann
2022-09-19 8:38 ` Guo Ren
2022-09-19 8:35 ` Guo Ren
2022-09-20 0:46 ` Guo Ren
2022-09-20 7:15 ` Arnd Bergmann
2022-09-21 6:11 ` Guo Ren
2022-09-20 7:17 ` Arnd Bergmann
2022-09-21 6:13 ` Guo Ren
2022-09-21 8:23 ` Guo Ren
2022-09-21 10:31 ` Guo Ren
2022-09-21 10:46 ` Guo Ren
2022-09-22 5:55 ` Arnd Bergmann
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