Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
x86/debug.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/x86/debug.c b/x86/debug.c
index b645e7b..f66d1d0 100644
--- a/x86/debug.c
+++ b/x86/debug.c
@@ -59,6 +59,13 @@ static void handle_db(struct ex_regs *regs)
}
}
+extern unsigned char handle_db_save_rip;
+asm("handle_db_save_rip:\n"
+ "stc\n"
+ "nop;nop;nop\n"
+ "rclq $1, n(%rip)\n"
+ "iretq\n");
+
static void handle_bp(struct ex_regs *regs)
{
bp_addr = regs->rip;
@@ -178,5 +185,50 @@ int main(int ac, char **av)
db_addr[0] == (unsigned long)&sw_icebp &&
dr6[0] == 0xffff0ff0);
+ set_dr7(0x400);
+ value = KERNEL_DS;
+ set_dr7(0x00f0040a); // 4-byte read or write
+
+ /*
+ * Each invocation of the handler should shift n by 1 and set bit 0 to 1.
+ * We expect a single invocation, so n should become 3. If the entry
+ * RIP is wrong, or if the handler is executed more than once, the value
+ * will not match.
+ */
+ set_idt_entry(1, &handle_db_save_rip, 0);
+
+ n = 1;
+ asm volatile(
+ "clc\n\t"
+ "mov %0,%%ss\n\t"
+ ".byte 0x2e, 0x2e, 0xf1"
+ : "=m" (value) : : "rax");
+ report("MOV SS + watchpoint + ICEBP", n == 3);
+
+ /*
+ * Here the #DB handler is invoked twice, once as a software exception
+ * and once as a software interrupt.
+ */
+ n = 1;
+ asm volatile(
+ "clc\n\t"
+ "mov %0,%%ss\n\t"
+ "int $1"
+ : "=m" (value) : : "rax");
+ report("MOV SS + watchpoint + int $1", n == 7);
+
+ /*
+ * Here the #DB and #BP handlers are invoked once each.
+ */
+ n = 1;
+ bp_addr = 0;
+ asm volatile(
+ "mov %0,%%ss\n\t"
+ ".byte 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0xcc\n\t"
+ "sw_bp2:"
+ : "=m" (value) : : "rax");
+ extern unsigned char sw_bp2;
+ report("MOV SS + watchpoint + INT3",
+ n == 3 && bp_addr == (unsigned long)&sw_bp2);
return report_summary();
}
--
1.8.3.1
