Some of the code test sequences (e.g. push_es) clobber ES. That causes
trouble for future rep string instructions. So save and restore ES
around the test code sequence in exec_in_big_real_mode.
Signed-off-by: Bill Wendling <morbo@xxxxxxxxxx>
---
x86/realmode.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/x86/realmode.c b/x86/realmode.c
index 5dbc2aa..629a221 100644
--- a/x86/realmode.c
+++ b/x86/realmode.c
@@ -164,7 +164,10 @@ static void exec_in_big_real_mode(struct insn_desc *insn)
"and $-2, %[tmp] \n\t"
"mov %[tmp], %%cr0 \n\t"
- "pushw %[save]+36; popfw \n\t"
+ /* Save ES, because it is clobbered by some tests. */
+ "pushw %%es \n\t"
+
+ "pushw %[save]+36; popfw \n\t"
"xchg %%eax, %[save]+0 \n\t"
"xchg %%ebx, %[save]+4 \n\t"
"xchg %%ecx, %[save]+8 \n\t"
@@ -190,6 +193,9 @@ static void exec_in_big_real_mode(struct insn_desc *insn)
"pushfl \n\t"
"popl %[save]+36 \n\t"
+ /* Restore ES for future rep string operations. */
+ "popw %%es \n\t"
+
/* Restore DF for the harness code */
"cld\n\t"
"xor %[tmp], %[tmp] \n\t"
@@ -1312,10 +1318,8 @@ static void test_lds_lss(void)
outregs.eax == (unsigned long)desc.address &&
outregs.ebx == desc.sel);
- MK_INSN(les, "push %es\n\t"
- "les (%ebx), %eax\n\t"
- "mov %es, %ebx\n\t"
- "pop %es\n\t");
+ MK_INSN(les, "les (%ebx), %eax\n\t"
+ "mov %es, %ebx\n\t");
exec_in_big_real_mode(&insn_les);
report("les", R_AX | R_BX,
outregs.eax == (unsigned long)desc.address &&
--
2.24.0.rc1.363.gb1bccd3e3d-goog
