Unverified Commit 2bf847db authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Palmer Dabbelt
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riscv: extable: add `type` and `data` fields 



This is a riscv port of commit d6e2cc56 ("arm64: extable: add `type`
and `data` fields").

Signed-off-by: default avatarJisheng Zhang <jszhang@kernel.org>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 6dd10d91

arch/riscv/include/asm/asm-extable.h

+17 −8
Original line number Diff line number Diff line
@@ -2,31 +2,40 @@ 
#ifndef __ASM_ASM_EXTABLE_H

#define __ASM_ASM_EXTABLE_H



#define EX_TYPE_NONE			0

#define EX_TYPE_FIXUP			1

#define EX_TYPE_BPF			2



#ifdef __ASSEMBLY__



#define __ASM_EXTABLE_RAW(insn, fixup)		\

#define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\

	.pushsection	__ex_table, "a";		\

	.balign		4;				\

	.long		((insn) - .);			\

	.long		((fixup) - .);			\

	.short		(type);				\

	.short		(data);				\

	.popsection;



	.macro		_asm_extable, insn, fixup

	__ASM_EXTABLE_RAW(\insn, \fixup)

	__ASM_EXTABLE_RAW(\insn, \fixup, EX_TYPE_FIXUP, 0)

	.endm



#else /* __ASSEMBLY__ */



#include <linux/stringify.h>



#define __ASM_EXTABLE_RAW(insn, fixup)			\

#define __ASM_EXTABLE_RAW(insn, fixup, type, data)	\

	".pushsection	__ex_table, \"a\"\n"		\

	".balign	4\n"				\

	".long		((" insn ") - .)\n"		\

	".long		((" fixup ") - .)\n"		\

	".short		(" type ")\n"			\

	".short		(" data ")\n"			\

	".popsection\n"



#define _ASM_EXTABLE(insn, fixup) __ASM_EXTABLE_RAW(#insn, #fixup)

#define _ASM_EXTABLE(insn, fixup)	\

	__ASM_EXTABLE_RAW(#insn, #fixup, __stringify(EX_TYPE_FIXUP), "0")



#endif /* __ASSEMBLY__ */

arch/riscv/include/asm/extable.h

+14 −3
Original line number Diff line number Diff line
@@ -17,17 +17,28 @@ 


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)



bool fixup_exception(struct pt_regs *regs);



#if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I)

bool rv_bpf_fixup_exception(const struct exception_table_entry *ex, struct pt_regs *regs);

bool ex_handler_bpf(const struct exception_table_entry *ex, struct pt_regs *regs);

#else

static inline bool

rv_bpf_fixup_exception(const struct exception_table_entry *ex,

ex_handler_bpf(const struct exception_table_entry *ex,

	       struct pt_regs *regs)

{

	return false;

arch/riscv/kernel/vmlinux.lds.S

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
 * Copyright (C) 2017 SiFive

 */



#define RO_EXCEPTION_TABLE_ALIGN	16

#define RO_EXCEPTION_TABLE_ALIGN	4



#ifdef CONFIG_XIP_KERNEL

#include "vmlinux-xip.lds.S"

arch/riscv/mm/extable.c

+21 −4
Original line number Diff line number Diff line
@@ -10,6 +10,20 @@ 
#include <linux/extable.h>

#include <linux/module.h>

#include <linux/uaccess.h>

#include <asm/asm-extable.h>



static inline unsigned long

get_ex_fixup(const struct exception_table_entry *ex)

{

	return ((unsigned long)&ex->fixup + ex->fixup);

}



static bool ex_handler_fixup(const struct exception_table_entry *ex,

			     struct pt_regs *regs)

{

	regs->epc = get_ex_fixup(ex);

	return true;

}



bool fixup_exception(struct pt_regs *regs)

{
@@ -19,9 +33,12 @@ bool fixup_exception(struct pt_regs *regs) 
	if (!ex)

		return false;



	if (regs->epc >= BPF_JIT_REGION_START && regs->epc < BPF_JIT_REGION_END)

		return rv_bpf_fixup_exception(ex, regs);

	switch (ex->type) {

	case EX_TYPE_FIXUP:

		return ex_handler_fixup(ex, regs);

	case EX_TYPE_BPF:

		return ex_handler_bpf(ex, regs);

	}



	regs->epc = (unsigned long)&ex->fixup + ex->fixup;

	return true;

	BUG();

}

arch/riscv/net/bpf_jit_comp64.c

+3 −2
Original line number Diff line number Diff line
@@ -459,7 +459,7 @@ static int emit_call(bool fixed, u64 addr, struct rv_jit_context *ctx) 
#define BPF_FIXUP_OFFSET_MASK   GENMASK(26, 0)

#define BPF_FIXUP_REG_MASK      GENMASK(31, 27)



bool rv_bpf_fixup_exception(const struct exception_table_entry *ex,

bool ex_handler_bpf(const struct exception_table_entry *ex,

		    struct pt_regs *regs)

{

	off_t offset = FIELD_GET(BPF_FIXUP_OFFSET_MASK, ex->fixup);
@@ -514,6 +514,7 @@ static int add_exception_handler(const struct bpf_insn *insn, 


	ex->fixup = FIELD_PREP(BPF_FIXUP_OFFSET_MASK, offset) |

		FIELD_PREP(BPF_FIXUP_REG_MASK, dst_reg);

	ex->type = EX_TYPE_BPF;



	ctx->nexentries++;

	return 0;