Users of handle_exception() should always save and restore the handlers.
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Michal Luczaj <mhal@xxxxxxx>
---
v1 -> v2: No changes
x86/emulator.c | 78 ++++++++++++++++++++++++++------------------------
1 file changed, 41 insertions(+), 37 deletions(-)
diff --git a/x86/emulator.c b/x86/emulator.c
index cd78e3c..769a049 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -710,6 +710,7 @@ static __attribute__((target("sse2"))) void test_sse_exceptions(void *cross_mem)
void *page2 = (void *)(&bytes[4096]);
struct pte_search search;
pteval_t orig_pte;
+ handler old;
// setup memory for unaligned access
mem = (uint32_t *)(&bytes[8]);
@@ -725,10 +726,10 @@ static __attribute__((target("sse2"))) void test_sse_exceptions(void *cross_mem)
asm("movupd %1, %0" : "=m"(*mem) : "x"(vv) : "memory");
report(sseeq(v, mem), "movupd unaligned");
exceptions = 0;
- handle_exception(GP_VECTOR, unaligned_movaps_handler);
+ old = handle_exception(GP_VECTOR, unaligned_movaps_handler);
asm("movaps %1, %0\n\t unaligned_movaps_cont:"
: "=m"(*mem) : "x"(vv));
- handle_exception(GP_VECTOR, 0);
+ handle_exception(GP_VECTOR, old);
report(exceptions == 1, "unaligned movaps exception");
// setup memory for cross page access
@@ -746,10 +747,10 @@ static __attribute__((target("sse2"))) void test_sse_exceptions(void *cross_mem)
invlpg(page2);
exceptions = 0;
- handle_exception(PF_VECTOR, cross_movups_handler);
+ old = handle_exception(PF_VECTOR, cross_movups_handler);
asm("movups %1, %0\n\t cross_movups_cont:" : "=m"(*mem) : "x"(vv) :
"memory");
- handle_exception(PF_VECTOR, 0);
+ handle_exception(PF_VECTOR, old);
report(exceptions == 1, "movups crosspage exception");
// restore invalidated page
@@ -817,36 +818,38 @@ static void advance_rip_and_note_exception(struct ex_regs *regs)
static void test_mmx_movq_mf(uint64_t *mem)
{
- /* movq %mm0, (%rax) */
- extern char movq_start, movq_end;
-
- uint16_t fcw = 0; /* all exceptions unmasked */
- write_cr0(read_cr0() & ~6); /* TS, EM */
- exceptions = 0;
- handle_exception(MF_VECTOR, advance_rip_and_note_exception);
- asm volatile("fninit; fldcw %0" : : "m"(fcw));
- asm volatile("fldz; fldz; fdivp"); /* generate exception */
-
- rip_advance = &movq_end - &movq_start;
- asm(KVM_FEP "movq_start: movq %mm0, (%rax); movq_end:");
- /* exit MMX mode */
- asm volatile("fnclex; emms");
- report(exceptions == 1, "movq mmx generates #MF");
- handle_exception(MF_VECTOR, 0);
+ /* movq %mm0, (%rax) */
+ extern char movq_start, movq_end;
+ handler old;
+
+ uint16_t fcw = 0; /* all exceptions unmasked */
+ write_cr0(read_cr0() & ~6); /* TS, EM */
+ exceptions = 0;
+ old = handle_exception(MF_VECTOR, advance_rip_and_note_exception);
+ asm volatile("fninit; fldcw %0" : : "m"(fcw));
+ asm volatile("fldz; fldz; fdivp"); /* generate exception */
+
+ rip_advance = &movq_end - &movq_start;
+ asm(KVM_FEP "movq_start: movq %mm0, (%rax); movq_end:");
+ /* exit MMX mode */
+ asm volatile("fnclex; emms");
+ report(exceptions == 1, "movq mmx generates #MF");
+ handle_exception(MF_VECTOR, old);
}
static void test_jmp_noncanonical(uint64_t *mem)
{
extern char nc_jmp_start, nc_jmp_end;
+ handler old;
*mem = 0x1111111111111111ul;
exceptions = 0;
rip_advance = &nc_jmp_end - &nc_jmp_start;
- handle_exception(GP_VECTOR, advance_rip_and_note_exception);
+ old = handle_exception(GP_VECTOR, advance_rip_and_note_exception);
asm volatile ("nc_jmp_start: jmp *%0; nc_jmp_end:" : : "m"(*mem));
report(exceptions == 1, "jump to non-canonical address");
- handle_exception(GP_VECTOR, 0);
+ handle_exception(GP_VECTOR, old);
}
static void test_movabs(uint64_t *mem)
@@ -979,22 +982,23 @@ static void ss_bad_rpl(struct ex_regs *regs)
static void test_sreg(volatile uint16_t *mem)
{
- u16 ss = read_ss();
+ u16 ss = read_ss();
+ handler old;
- // check for null segment load
- *mem = 0;
- asm volatile("mov %0, %%ss" : : "m"(*mem));
- report(read_ss() == 0, "mov null, %%ss");
-
- // check for exception when ss.rpl != cpl on null segment load
- exceptions = 0;
- handle_exception(GP_VECTOR, ss_bad_rpl);
- *mem = 3;
- asm volatile("mov %0, %%ss; ss_bad_rpl_cont:" : : "m"(*mem));
- report(exceptions == 1 && read_ss() == 0,
- "mov null, %%ss (with ss.rpl != cpl)");
- handle_exception(GP_VECTOR, 0);
- write_ss(ss);
+ // check for null segment load
+ *mem = 0;
+ asm volatile("mov %0, %%ss" : : "m"(*mem));
+ report(read_ss() == 0, "mov null, %%ss");
+
+ // check for exception when ss.rpl != cpl on null segment load
+ exceptions = 0;
+ old = handle_exception(GP_VECTOR, ss_bad_rpl);
+ *mem = 3;
+ asm volatile("mov %0, %%ss; ss_bad_rpl_cont:" : : "m"(*mem));
+ report(exceptions == 1 && read_ss() == 0,
+ "mov null, %%ss (with ss.rpl != cpl)");
+ handle_exception(GP_VECTOR, old);
+ write_ss(ss);
}
static uint64_t usr_gs_mov(void)
--
2.37.1
