linux/arch/riscv/include/asm/extable.h
Jisheng Zhang de658bcf03
riscv: mm: stub extable related functions/macros for !MMU
extable relies on the MMU to work properly, so it's useless to
include __ex_table sections and build extable related functions for
!MMU case.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20230509152641.805-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-14 07:17:45 -07:00

53 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_RISCV_EXTABLE_H
#define _ASM_RISCV_EXTABLE_H
/*
* The exception table consists of pairs of relative offsets: the first
* is the relative offset to an instruction that is allowed to fault,
* and the second is the relative offset at which the program should
* continue. No registers are modified, so it is entirely up to the
* continuation code to figure out what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry {
int insn, fixup;
short type, data;
};
#define ARCH_HAS_RELATIVE_EXTABLE
#define swap_ex_entry_fixup(a, b, tmp, delta) \
do { \
(a)->fixup = (b)->fixup + (delta); \
(b)->fixup = (tmp).fixup - (delta); \
(a)->type = (b)->type; \
(b)->type = (tmp).type; \
(a)->data = (b)->data; \
(b)->data = (tmp).data; \
} while (0)
#ifdef CONFIG_MMU
bool fixup_exception(struct pt_regs *regs);
#else
static inline bool fixup_exception(struct pt_regs *regs) { return false; }
#endif
#if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I)
bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs);
#else
static inline bool
ex_handler_bpf(const struct exception_table_entry *ex,
struct pt_regs *regs)
{
return false;
}
#endif
#endif