[PATCH] Provide a NetBSD specific aarch64 cpu_signal_handler

[Nick Hudson <skrll@netbsd.org>]

Fix qemu build on NetBSD/evbarm-aarch64 by providing a NetBSD specific
cpu_signal_handler.

Signed-off-by: Nick Hudson <skrll@netbsd.org>
---
 accel/tcg/user-exec.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 4be78eb9b3..dd128adc00 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -523,6 +523,31 @@ int cpu_signal_handler(int host_signum, void *pinfo,
 
 #elif defined(__aarch64__)
 
+#if defined(__NetBSD__)
+
+#include <ucontext.h>
+#include <sys/siginfo.h>
+
+int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
+{
+    ucontext_t *uc = puc;
+    siginfo_t *si = pinfo;
+    unsigned long pc;
+    int is_write;
+    uint32_t esr;
+
+    pc = uc->uc_mcontext.__gregs[_REG_PC];
+    esr = si->si_trap;
+
+    /* siginfo_t::si_trap is the ESR value, for data aborts ESR.EC
+     * is 0b10010x: then bit 6 is the WnR bit
+     */
+    is_write = extract32(esr, 27, 5) == 0x12 && extract32(esr, 6, 1) == 1;
+    return handle_cpu_signal(pc, si, is_write, &uc->uc_sigmask);
+}
+
+#else
+
 #ifndef ESR_MAGIC
 /* Pre-3.16 kernel headers don't have these, so provide fallback definitions */
 #define ESR_MAGIC 0x45535201
@@ -585,6 +610,7 @@ int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
     }
     return handle_cpu_signal(pc, info, is_write, &uc->uc_sigmask);
 }
+#endif
 
 #elif defined(__s390__)
 
-- 
2.17.1