riscv: Add the support for c.ebreak check in is_valid_bugaddr()
authorVincent Chen <vincentc@andestech.com>
Tue, 5 Mar 2019 03:23:34 +0000 (11:23 +0800)
committerPalmer Dabbelt <palmer@sifive.com>
Fri, 17 May 2019 03:42:12 +0000 (20:42 -0700)
commitee72e0e70cf7c846a4e0b6160f771da8f68571dc
treed08fef2622f07eb5df0825c147348fe149c696f3
parentd18ebc274ca78f61094fba39ec9f206d46be5a85
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>
arch/riscv/include/asm/bug.h
arch/riscv/kernel/traps.c