Messages in this thread Patch in this message | | | From | Guo Ren <> | Date | Sat, 10 Sep 2022 17:17:44 +0800 | Subject | Re: [PATCH V4 4/8] riscv: traps: Add noinstr to prevent instrumentation inserted |
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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
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