[PATCH] riscv: mm: stub extable related functions/macros for !MMU

Jisheng Zhang
2023-05-09T15:16:02Z

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>
---
arch/riscv/include/asm/asm-extable.h | 6 ++++++
arch/riscv/include/asm/extable.h | 4 ++++
arch/riscv/mm/Makefile | 3 +--
3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/asm-extable.h b/arch/riscv/include/asm/asm-extable.h
index 14be0673f5b5..909d6beaf499 100644
--- a/arch/riscv/include/asm/asm-extable.h
+++ b/arch/riscv/include/asm/asm-extable.h
@@ -7,6 +7,8 @@
#define EX_TYPE_BPF 2
#define EX_TYPE_UACCESS_ERR_ZERO 3

+#ifdef MMU
+
#ifdef __ASSEMBLY__

#define __ASM_EXTABLE_RAW(insn, fixup, type, data) \
@@ -62,4 +64,8 @@

#endif /* __ASSEMBLY__ */

+#else /* CONFIG_MMU */
+ #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)
+#endif /* CONFIG_MMU */
+
#endif /* __ASM_ASM_EXTABLE_H */
diff --git a/arch/riscv/include/asm/extable.h b/arch/riscv/include/asm/extable.h
index 512012d193dc..3eb5c1f7bf34 100644
--- a/arch/riscv/include/asm/extable.h
+++ b/arch/riscv/include/asm/extable.h
@@ -32,7 +32,11 @@ do { \
(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);
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index b85e9e82f082..9c454f90fd3d 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -13,8 +13,7 @@ endif
KCOV_INSTRUMENT_init.o := n

obj-y += init.o
-obj-y += extable.o
-obj-$(CONFIG_MMU) += fault.o pageattr.o
+obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o
obj-y += cacheflush.o
obj-y += context.o
obj-y += pgtable.o
--
2.40.0

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