From fef40be6da856afead4177aaa9d869a66fb3381f Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Fri, 16 Jun 2017 00:12:53 +0100 Subject: [PATCH] MIPS: Send SIGILL for linked branches in `__compute_return_epc_for_insn' Fix commit 319824eabc3f ("MIPS: kernel: branch: Do not emulate the branch likelies on MIPS R6") and also send SIGILL rather than returning -SIGILL for BLTZAL, BLTZALL, BGEZAL and BGEZALL instruction encodings no longer supported in R6, except where emulated. Returning -SIGILL is never correct as the API defines this function's result upon error to be -EFAULT and a signal actually issued. Fixes: 319824eabc3f ("MIPS: kernel: branch: Do not emulate the branch likelies on MIPS R6") Signed-off-by: Maciej W. Rozycki Cc: James Hogan Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # 3.19+ Patchwork: https://patchwork.linux-mips.org/patch/16398/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/branch.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c index df5c32b38408d..64c8360e3d62e 100644 --- a/arch/mips/kernel/branch.c +++ b/arch/mips/kernel/branch.c @@ -473,10 +473,8 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, case bltzal_op: case bltzall_op: if (NO_R6EMU && (insn.i_format.rs || - insn.i_format.rt == bltzall_op)) { - ret = -SIGILL; - break; - } + insn.i_format.rt == bltzall_op)) + goto sigill_r2r6; regs->regs[31] = epc + 8; /* * OK we are here either because we hit a NAL @@ -507,10 +505,8 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, case bgezal_op: case bgezall_op: if (NO_R6EMU && (insn.i_format.rs || - insn.i_format.rt == bgezall_op)) { - ret = -SIGILL; - break; - } + insn.i_format.rt == bgezall_op)) + goto sigill_r2r6; regs->regs[31] = epc + 8; /* * OK we are here either because we hit a BAL -- 2.39.5