linux-user: Renumber TARGET_QEMU_ESIGRETURN, make it not arch-specific

Currently we define a QEMU-internal errno TARGET_QEMU_ESIGRETURN
only on the MIPS and PPC targets; move this to errno_defs.h
so it is available for all architectures, and renumber it to 513.
We pick 513 because this is safe from future use as a system call return
value: Linux uses it as ERESTART_NOINTR internally and never allows that
errno to escape to userspace.

Signed-off-by: Timothy Edward Baldwin <[email protected]>
Message-id: 1441497448[email protected]
[PMM: TARGET_ERESTARTSYS split out into preceding patch, add comment]
Reviewed-by: Peter Maydell <[email protected]>
Reviewed-by: Laurent Vivier <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>
Signed-off-by: Riku Voipio <[email protected]>

diff --git a/linux-user/errno_defs.h b/linux-user/errno_defs.h
index b7a8c9ff951b5cef3f8280f4b9dc157523691c89..65522c45160ee8a92cd54f9a86f46d9e49dd467a 100644 (file)
--- a/linux-user/errno_defs.h
+++ b/linux-user/errno_defs.h
@@ -147,3 +147,12 @@
  * kernel uses for the same purpose.
  */
 #define TARGET_ERESTARTSYS     512     /* Restart system call (if SA_RESTART) */
+
+/* QEMU internal, not visible to the guest. This is returned by the
+ * do_sigreturn() code after a successful sigreturn syscall, to indicate
+ * that it has correctly set the guest registers and so the main loop
+ * should not touch them. We use the value the guest would use for
+ * ERESTART_NOINTR (which is kernel internal) to guarantee that we won't
+ * clash with a valid guest errno now or in the future.
+ */
+#define TARGET_QEMU_ESIGRETURN 513     /* Return from signal */

diff --git a/linux-user/mips/target_syscall.h b/linux-user/mips/target_syscall.h
index 68db160e535639736d8da3a824bee687dd7faef1..e8e305cc9c198122aa03c7315501a098fe5b03bb 100644 (file)
--- a/linux-user/mips/target_syscall.h
+++ b/linux-user/mips/target_syscall.h
@@ -222,10 +222,6 @@ struct target_pt_regs {
 #define TARGET_ENOTRECOVERABLE 166     /* State not recoverable */
 
 
-
-/* Nasty hack: define a fake errno value for use by sigreturn.  */
-#define TARGET_QEMU_ESIGRETURN 255
-
 #define UNAME_MACHINE "mips"
 #define UNAME_MINIMUM_RELEASE "2.6.32"
 

diff --git a/linux-user/mips64/target_syscall.h b/linux-user/mips64/target_syscall.h
index 0e0c2d232f97c015c5510107ec7d61632e219b29..5789e8615078b903468268d480e0299f9a4795d5 100644 (file)
--- a/linux-user/mips64/target_syscall.h
+++ b/linux-user/mips64/target_syscall.h
@@ -219,10 +219,6 @@ struct target_pt_regs {
 #define TARGET_ENOTRECOVERABLE 166     /* State not recoverable */
 
 
-
-/* Nasty hack: define a fake errno value for use by sigreturn. */
-#define TARGET_QEMU_ESIGRETURN 255
-
 #define UNAME_MACHINE "mips64"
 #define UNAME_MINIMUM_RELEASE "2.6.32"
 

diff --git a/linux-user/ppc/target_syscall.h b/linux-user/ppc/target_syscall.h
index 35cab5946257aa49432b0257d0a38211dc3a2511..7ca83c228093f20f4ab1cf32d11509d215880ff3 100644 (file)
--- a/linux-user/ppc/target_syscall.h
+++ b/linux-user/ppc/target_syscall.h
@@ -53,8 +53,6 @@ struct target_revectored_struct {
        abi_ulong __map[8];                     /* 256 bits */
 };
 
-/* Nasty hack: define a fake errno value for use by sigreturn.  */
-#define TARGET_QEMU_ESIGRETURN 255
 
 /*
  * flags masks