| Message ID | 20220908022506.1275799-5-guoren@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: Add GENERIC_ENTRY, irq stack support | expand |
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.
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
On Sat, Sep 10, 2022 at 5:17 PM Guo Ren <guoren@kernel.org> wrote: > > 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 How about let __section(".xip.traps") replace the __section__(".noinstr.text")? +#define __trap_section noinstr __attribute(__section(".xip.traps")) > #else > -#define __trap_section > +#define __trap_section noinstr > #endif > > > -- > Best Regards > Guo Ren
On Sat, Sep 10, 2022 at 05:17:44PM +0800, Guo Ren wrote: > > > -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 This is almost guaranteed to get out of sync when the compiler guys add yet another sanitizier. Please consider picking up this patch: https://lore.kernel.org/all/20211110115736.3776-7-jiangshanlai@gmail.com/ and using __noinstr_section(".xip.traps")
On Sun, Sep 11, 2022 at 11:09 PM Peter Zijlstra <peterz@infradead.org> wrote: > > On Sat, Sep 10, 2022 at 05:17:44PM +0800, Guo Ren wrote: > > > > > -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 > > This is almost guaranteed to get out of sync when the compiler guys add > yet another sanitizier. Please consider picking up this patch: > > https://lore.kernel.org/all/20211110115736.3776-7-jiangshanlai@gmail.com/ Thx, that is what I want. > > and using __noinstr_section(".xip.traps")
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) \ { \ do_trap_error(regs, signo, code, regs->epc, "Oops - " str); \ } @@ -121,7 +121,7 @@ DO_ERROR_INFO(do_trap_store_misaligned, int handle_misaligned_load(struct pt_regs *regs); int handle_misaligned_store(struct pt_regs *regs); -asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs) +asmlinkage __trap_section void noinstr do_trap_load_misaligned(struct pt_regs *regs) { if (!handle_misaligned_load(regs)) return; @@ -129,7 +129,7 @@ asmlinkage void __trap_section do_trap_load_misaligned(struct pt_regs *regs) "Oops - load address misaligned"); } -asmlinkage void __trap_section do_trap_store_misaligned(struct pt_regs *regs) +asmlinkage __trap_section void noinstr do_trap_store_misaligned(struct pt_regs *regs) { if (!handle_misaligned_store(regs)) return; @@ -156,7 +156,7 @@ static inline unsigned long get_break_insn_length(unsigned long pc) return GET_INSN_LENGTH(insn); } -asmlinkage __visible __trap_section void do_trap_break(struct pt_regs *regs) +asmlinkage __visible __trap_section void noinstr do_trap_break(struct pt_regs *regs) { #ifdef CONFIG_KPROBES if (kprobe_single_step_handler(regs)) diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index f2fbd1400b7c..c7829289e806 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -203,7 +203,7 @@ 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) { struct task_struct *tsk; struct vm_area_struct *vma;