Unverified Commit d0db02c6 authored by Guo Ren's avatar Guo Ren Committed by Palmer Dabbelt
Browse files

riscv: entry: Add noinstr to prevent instrumentation inserted 

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/


Reviewed-by: default avatarBjörn Töpel <bjorn@rivosinc.com>
Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
Tested-by: default avatarJisheng Zhang <jszhang@kernel.org>
Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
Signed-off-by: default avatarGuo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230222033021.983168-4-guoren@kernel.org


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 8574bf8d

arch/riscv/kernel/traps.c

+2 −2
Original line number Diff line number Diff line
@@ -119,9 +119,9 @@ 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)	\