From f81393a5b252df772b934cde81b7e16273afbd43 Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Sun, 23 Jan 2022 17:04:17 +0800 Subject: [PATCH] riscv: extable: fix err reg writing in dedicated uaccess handler Mayuresh reported commit 20802d8d477d ("riscv: extable: add a dedicated uaccess handler") breaks the writev02 test case in LTP. This is due to the err reg isn't correctly set with the errno(-EFAULT in writev02 case). First of all, the err and zero regs are reg numbers rather than reg offsets in struct pt_regs; Secondly, regs_set_gpr() should write the regs when offset isn't zero(zero means epc) Fix it by correcting regs_set_gpr() logic and passing the correct reg offset to it. Reported-by: Mayuresh Chitale Fixes: 20802d8d477d ("riscv: extable: add a dedicated uaccess handler") Signed-off-by: Jisheng Zhang Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/extable.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/riscv/mm/extable.c b/arch/riscv/mm/extable.c index 05978f78579f..35484d830fd6 100644 --- a/arch/riscv/mm/extable.c +++ b/arch/riscv/mm/extable.c @@ -33,7 +33,7 @@ static inline void regs_set_gpr(struct pt_regs *regs, unsigned int offset, if (unlikely(offset > MAX_REG_OFFSET)) return; - if (!offset) + if (offset) *(unsigned long *)((unsigned long)regs + offset) = val; } @@ -43,8 +43,8 @@ static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex, int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data); int reg_zero = FIELD_GET(EX_DATA_REG_ZERO, ex->data); - regs_set_gpr(regs, reg_err, -EFAULT); - regs_set_gpr(regs, reg_zero, 0); + regs_set_gpr(regs, reg_err * sizeof(unsigned long), -EFAULT); + regs_set_gpr(regs, reg_zero * sizeof(unsigned long), 0); regs->epc = get_ex_fixup(ex); return true; -- 2.11.0