[PULL 25/68] target/arm/arm-semi: Capture errno in softmmu version of set_swi_errno()

[Peter Maydell <peter.maydell@linaro.org>]

The set_swi_errno() function is called to capture the errno
from a host system call, so that we can return -1 from the
semihosting function and later allow the guest to get a more
specific error code with the SYS_ERRNO function. It comes in
two versions, one for user-only and one for softmmu. We forgot
to capture the errno in the softmmu version; fix the error.

(Semihosting calls directed to gdb are unaffected because
they go through a different code path that captures the
error return from the gdbstub call in arm_semi_cb() or
arm_semi_flen_cb().)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-2-peter.maydell@linaro.org
---
 target/arm/arm-semi.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/target/arm/arm-semi.c b/target/arm/arm-semi.c
index 90423a35deb..03e60105c05 100644
--- a/target/arm/arm-semi.c
+++ b/target/arm/arm-semi.c
@@ -114,8 +114,13 @@ static inline uint32_t set_swi_errno(TaskState *ts, uint32_t code)
     return code;
 }
 #else
+static target_ulong syscall_err;
+
 static inline uint32_t set_swi_errno(CPUARMState *env, uint32_t code)
 {
+    if (code == (uint32_t)-1) {
+        syscall_err = errno;
+    }
     return code;
 }
 
@@ -124,10 +129,6 @@ static inline uint32_t set_swi_errno(CPUARMState *env, uint32_t code)
 
 static target_ulong arm_semi_syscall_len;
 
-#if !defined(CONFIG_USER_ONLY)
-static target_ulong syscall_err;
-#endif
-
 static void arm_semi_cb(CPUState *cs, target_ulong ret, target_ulong err)
 {
     ARMCPU *cpu = ARM_CPU(cs);
-- 
2.20.1