On Wed, Jan 4, 2023 at 7:55 PM Mark Rutland <mark.rutland@xxxxxxx> wrote: > > On Mon, Jan 02, 2023 at 10:35:27PM -0500, guoren@xxxxxxxxxx wrote: > > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > > > 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) > > That's generally true, and makes sense to me, but .... > > > Link: https://lore.kernel.org/linux-riscv/YxcQ6NoPf3AH0EXe@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > Reviewed-by: Björn Töpel <bjorn@xxxxxxxxxxxx> > > Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Tested-by: Jisheng Zhang <jszhang@xxxxxxxxxx> > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > Signed-off-by: Guo Ren <guoren@xxxxxxxxxx> > > --- > > arch/riscv/kernel/traps.c | 4 ++-- > > arch/riscv/mm/fault.c | 2 +- > > 2 files changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c > > index 549bde5c970a..96ec76c54ff2 100644 > > --- a/arch/riscv/kernel/traps.c > > +++ b/arch/riscv/kernel/traps.c > > @@ -95,9 +95,9 @@ 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 __noinstr_section(".xip.traps") > > #else > > -#define __trap_section > > +#define __trap_section noinstr > > #endif > > #define DO_ERROR_INFO(name, signo, code, str) \ > > asmlinkage __visible __trap_section void name(struct pt_regs *regs) \ > > diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c > > index d86f7cebd4a7..b26f68eac61c 100644 > > --- a/arch/riscv/mm/fault.c > > +++ b/arch/riscv/mm/fault.c > > @@ -204,7 +204,7 @@ static inline bool access_error(unsigned long cause, struct vm_area_struct *vma) > > * This routine handles page faults. It determines the address and the > > * problem, and then passes it off to one of the appropriate routines. > > */ > > -asmlinkage void do_page_fault(struct pt_regs *regs) > > +asmlinkage void noinstr do_page_fault(struct pt_regs *regs) > > ... why do you need that for do_page_fault? That doesn't (currently) do any > entry/exit logic, so this seems unnecessary per the commit description. Yes, the above is unnecessary; I've fixed it in v13. > > Thanks, > Mark. > > > { > > struct task_struct *tsk; > > struct vm_area_struct *vma; > > -- > > 2.36.1 > > -- Best Regards Guo Ren
