riscv: Add the support for c.ebreak check in is_valid_bugaddr()

The macro __BUG_INSN currently is defined as the "ebreak" opcode.
The is_valid_bugaddr() function compares the instruction pointed to by
$sepc with macro __BUG_INSN to check whether the current trap exception
is caused by an "ebreak" instruction. However, this check flow is possibly
erroneous because if C extension is supported, the expected trap
instruction "ebreak" is possibly translated to "c.ebreak" by the assembler.
Therefore, it requires a mechanism to distinguish the length of the
instruction in $spec and compare it to the correct trap instruction.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Vincent Chen
2019-03-05 11:23:34 +08:00
committed by Palmer Dabbelt
parent d18ebc274c
commit ee72e0e70c
2 changed files with 23 additions and 4 deletions

View File

@@ -21,7 +21,12 @@
#include <asm/asm.h>
#ifdef CONFIG_GENERIC_BUG
#define __BUG_INSN _AC(0x00100073, UL) /* ebreak */
#define __INSN_LENGTH_MASK _UL(0x3)
#define __INSN_LENGTH_32 _UL(0x3)
#define __COMPRESSED_INSN_MASK _UL(0xffff)
#define __BUG_INSN_32 _UL(0x00100073) /* ebreak */
#define __BUG_INSN_16 _UL(0x9002) /* c.ebreak */
#ifndef __ASSEMBLY__
typedef u32 bug_insn_t;