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authorThomas Huth <thuth@redhat.com>2022-12-01 19:44:43 +0100
committerThomas Huth <thuth@redhat.com>2022-12-03 22:04:40 +0100
commit21be74a9a59d1e4954ebb59dcbee0fda0b19de00 (patch)
tree08c7b4fc054bcc9e9c79d92a4256bcfb6e2d7573 /target/s390x
parent0f0a9e4e5c38c45ca7e6ac09cb36db21d42ec6dd (diff)
target/s390x/tcg: Fix and improve the SACF instruction
The SET ADDRESS SPACE CONTROL FAST instruction is not privileged, it can be used from problem space, too. Just the switching to the home address space is privileged and should still generate a privilege exception. This bug is e.g. causing programs like Java that use the "getcpu" vdso kernel function to crash (see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=990417#26 ). While we're at it, also check if DAT is not enabled. In that case the instruction is supposed to generate a special operation exception. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/655 Message-Id: <20221201184443.136355-1-thuth@redhat.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
Diffstat (limited to 'target/s390x')
-rw-r--r--target/s390x/tcg/cc_helper.c7
-rw-r--r--target/s390x/tcg/insn-data.h.inc2
2 files changed, 8 insertions, 1 deletions
diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c
index b2e8d3d9f5..b36f8cdc8b 100644
--- a/target/s390x/tcg/cc_helper.c
+++ b/target/s390x/tcg/cc_helper.c
@@ -487,6 +487,10 @@ void HELPER(sacf)(CPUS390XState *env, uint64_t a1)
{
HELPER_LOG("%s: %16" PRIx64 "\n", __func__, a1);
+ if (!(env->psw.mask & PSW_MASK_DAT)) {
+ tcg_s390_program_interrupt(env, PGM_SPECIAL_OP, GETPC());
+ }
+
switch (a1 & 0xf00) {
case 0x000:
env->psw.mask &= ~PSW_MASK_ASC;
@@ -497,6 +501,9 @@ void HELPER(sacf)(CPUS390XState *env, uint64_t a1)
env->psw.mask |= PSW_ASC_SECONDARY;
break;
case 0x300:
+ if ((env->psw.mask & PSW_MASK_PSTATE) != 0) {
+ tcg_s390_program_interrupt(env, PGM_PRIVILEGED, GETPC());
+ }
env->psw.mask &= ~PSW_MASK_ASC;
env->psw.mask |= PSW_ASC_HOME;
break;
diff --git a/target/s390x/tcg/insn-data.h.inc b/target/s390x/tcg/insn-data.h.inc
index 7e952bdfc8..54d4250c9f 100644
--- a/target/s390x/tcg/insn-data.h.inc
+++ b/target/s390x/tcg/insn-data.h.inc
@@ -1365,7 +1365,7 @@
/* SERVICE CALL LOGICAL PROCESSOR (PV hypercall) */
F(0xb220, SERVC, RRE, Z, r1_o, r2_o, 0, 0, servc, 0, IF_PRIV | IF_IO)
/* SET ADDRESS SPACE CONTROL FAST */
- F(0xb279, SACF, S, Z, 0, a2, 0, 0, sacf, 0, IF_PRIV)
+ C(0xb279, SACF, S, Z, 0, a2, 0, 0, sacf, 0)
/* SET CLOCK */
F(0xb204, SCK, S, Z, 0, m2_64a, 0, 0, sck, 0, IF_PRIV | IF_IO)
/* SET CLOCK COMPARATOR */