From 537d3e8e6beea9a0fbd6469eb38450e718244dad Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Thu, 14 Apr 2016 17:14:53 +0200 Subject: [PATCH] ppc: Fix the bad exception NIP value and the range check in LSWX The range checks in the LSWX instruction are completely insufficient: They do not take the wrap-around case into account, and the check "reg < rx" should be "reg <= rx" instead. Fix it by using the new lsw_reg_in_range() helper function that is already used for LSWI, too. Then there is a second problem: In case the INVAL exception is generated, the NIP value is wrong, it currently points to the instruction before the LSWX instruction. This is because gen_lswx() already decreases the NIP value by 4 (to be prepared for page fault exceptions), and powerpc_excp() later decreases it again by 4 while handling the program exception. So to get this right, we've got to undo the "- 4" from gen_lswx() here before calling helper_raise_exception_err(). Signed-off-by: Thomas Huth Signed-off-by: David Gibson --- target-ppc/mem_helper.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/target-ppc/mem_helper.c b/target-ppc/mem_helper.c index 581d9faa23..6d584c9126 100644 --- a/target-ppc/mem_helper.c +++ b/target-ppc/mem_helper.c @@ -102,8 +102,9 @@ void helper_lswx(CPUPPCState *env, target_ulong addr, uint32_t reg, { if (likely(xer_bc != 0)) { int num_used_regs = (xer_bc + 3) / 4; - if (unlikely((ra != 0 && reg < ra && (reg + num_used_regs) > ra) || - (reg < rb && (reg + num_used_regs) > rb))) { + if (unlikely((ra != 0 && lsw_reg_in_range(reg, num_used_regs, ra)) || + lsw_reg_in_range(reg, num_used_regs, rb))) { + env->nip += 4; /* Compensate the "nip - 4" from gen_lswx() */ helper_raise_exception_err(env, POWERPC_EXCP_PROGRAM, POWERPC_EXCP_INVAL | POWERPC_EXCP_INVAL_LSWX);