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authorThomas Huth <thuth@redhat.com>2016-04-14 17:14:53 +0200
committerDavid Gibson <david@gibson.dropbear.id.au>2016-04-18 15:14:38 +1000
commit537d3e8e6beea9a0fbd6469eb38450e718244dad (patch)
tree89b8bd2b951197ebc8d5500168518422f41cb6ae
parentafbee7128c2399b6fca7b744ee560e3a1851118e (diff)
downloadqemu-arm-537d3e8e6beea9a0fbd6469eb38450e718244dad.tar.gz
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 <thuth@redhat.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
-rw-r--r--target-ppc/mem_helper.c5
1 files 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);