linux-user: Clean up handling of clone() argument order

Linux manages to have three separate orderings of the arguments to
the clone() syscall on different architectures. In the kernel these
are selected via CONFIG_CLONE_BACKWARDS and CONFIG_CLONE_BACKWARDS2.
Clean up our implementation of this to use similar #define names
rather than a TARGET_* ifdef ladder.

This includes behaviour changes fixing bugs on cris, x86-64, m68k,
openrisc and unicore32.  cris had explicit but wrong handling; the
others were just incorrectly using QEMU's default, which happened
to be the equivalent of CONFIG_CLONE_BACKWARDS. (unicore32 appears
to be broken in the mainline kernel in that it tries to use arg3 for
both parent_tidptr and newtls simultaneously -- we don't attempt
to emulate this bug...)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>

diff --git a/linux-user/arm/syscall.h b/linux-user/arm/syscall.h
index 003d42470172115cd48e9f944fc448fe77d8bc41..73f29314f68677f45d5ca371cf4d58b016a2847c 100644 (file)
--- a/linux-user/arm/syscall.h
+++ b/linux-user/arm/syscall.h
@@ -40,3 +40,5 @@ struct target_pt_regs {
 #else
 #define UNAME_MACHINE "armv5tel"
 #endif
+
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/cris/syscall.h b/linux-user/cris/syscall.h
index 50e50b4f3f242fb504abf111131ceac2218957fa..832ee64bd83efb0fa77b7cf0e0335cb589c64d4f 100644 (file)
--- a/linux-user/cris/syscall.h
+++ b/linux-user/cris/syscall.h
@@ -38,4 +38,6 @@ struct target_pt_regs {
         unsigned long eda;
 };
 
+#define TARGET_CLONE_BACKWARDS2
+
 #endif

diff --git a/linux-user/i386/syscall.h b/linux-user/i386/syscall.h
index 266e2c4c83f22756e51fdd5c2a6cce22c527cff0..12b8c3b672999da280f5f1ac54aeeec136c8df76 100644 (file)
--- a/linux-user/i386/syscall.h
+++ b/linux-user/i386/syscall.h
@@ -144,3 +144,5 @@ struct target_vm86plus_struct {
 };
 
 #define UNAME_MACHINE "i686"
+
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/microblaze/syscall.h b/linux-user/microblaze/syscall.h
index c3e5c55b3d4d468962dd9732472f6bc8ee4fd3d0..d550989d5e495485415e824b93f330343b7889fc 100644 (file)
--- a/linux-user/microblaze/syscall.h
+++ b/linux-user/microblaze/syscall.h
@@ -48,4 +48,6 @@ struct target_pt_regs {
         uint32_t kernel_mode;
 };
 
+#define TARGET_CLONE_BACKWARDS
+
 #endif

diff --git a/linux-user/mips/syscall.h b/linux-user/mips/syscall.h
index 3deb862cc4f636a96913f5157b25864fa7fadac0..9d437d918bdd128c566cbf26976f8543d1f55cbb 100644 (file)
--- a/linux-user/mips/syscall.h
+++ b/linux-user/mips/syscall.h
@@ -225,3 +225,5 @@ struct target_pt_regs {
 #define TARGET_QEMU_ESIGRETURN 255
 
 #define UNAME_MACHINE "mips"
+
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/mips64/syscall.h b/linux-user/mips64/syscall.h
index cd707df32f346a3e1de7c6be25774283456eac28..1710f766e26b09d7ee81cef420ce01feb4d0e0f4 100644 (file)
--- a/linux-user/mips64/syscall.h
+++ b/linux-user/mips64/syscall.h
@@ -222,3 +222,5 @@ struct target_pt_regs {
 #define TARGET_QEMU_ESIGRETURN 255
 
 #define UNAME_MACHINE "mips64"
+
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/ppc/syscall.h b/linux-user/ppc/syscall.h
index 481047b2dd6d3430cf96c40acf9cd55d96a5c5a8..ba36acbc337b677770a925b9215caf8b808d5e02 100644 (file)
--- a/linux-user/ppc/syscall.h
+++ b/linux-user/ppc/syscall.h
@@ -62,3 +62,5 @@ struct target_revectored_struct {
 #else
 #define UNAME_MACHINE "ppc"
 #endif
+
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/s390x/syscall.h b/linux-user/s390x/syscall.h
index e4603b79c3d47f986633d7cc2703ccd141e20d1b..ea8c30484052a9367d504db9359d6926726ddf9c 100644 (file)
--- a/linux-user/s390x/syscall.h
+++ b/linux-user/s390x/syscall.h
@@ -21,3 +21,5 @@ struct target_pt_regs {
 };
 
 #define UNAME_MACHINE "s390x"
+
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/sparc/syscall.h b/linux-user/sparc/syscall.h
index 5a9bb7e546983201b106d47d3c74571d21dd9c1b..4cd64bf41dd2d96b02f3324627769b7dc27e029f 100644 (file)
--- a/linux-user/sparc/syscall.h
+++ b/linux-user/sparc/syscall.h
@@ -7,3 +7,10 @@ struct target_pt_regs {
 };
 
 #define UNAME_MACHINE "sun4"
+
+/* SPARC kernels don't define this in their Kconfig, but they have the
+ * same ABI as if they did, implemented by sparc-specific code which fishes
+ * directly in the u_regs() struct for half the parameters in sparc_do_fork()
+ * and copy_thread().
+ */
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/sparc64/syscall.h b/linux-user/sparc64/syscall.h
index 81a816de94a37da75145b57e7a9e626ec285ffc5..e60bf311c02e1d9817f61364f0f9312dbf2f56d1 100644 (file)
--- a/linux-user/sparc64/syscall.h
+++ b/linux-user/sparc64/syscall.h
@@ -8,3 +8,10 @@ struct target_pt_regs {
 };
 
 #define UNAME_MACHINE "sun4u"
+
+/* SPARC kernels don't define this in their Kconfig, but they have the
+ * same ABI as if they did, implemented by sparc-specific code which fishes
+ * directly in the u_regs() struct for half the parameters in sparc_do_fork()
+ * and copy_thread().
+ */
+#define TARGET_CLONE_BACKWARDS

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 642d0a362072ad73e859ae2cf01d7b64e872e495..b167d7f3aeddf0c979bac698776c7477e2d0d588 100644 (file)
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6956,16 +6956,20 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
         ret = get_errno(fsync(arg1));
         break;
     case TARGET_NR_clone:
-#if defined(TARGET_SH4) || defined(TARGET_ALPHA)
-        ret = get_errno(do_fork(cpu_env, arg1, arg2, arg3, arg5, arg4));
-#elif defined(TARGET_CRIS)
-        ret = get_errno(do_fork(cpu_env, arg2, arg1, arg3, arg4, arg5));
-#elif defined(TARGET_MICROBLAZE)
+        /* Linux manages to have three different orderings for its
+         * arguments to clone(); the BACKWARDS and BACKWARDS2 defines
+         * match the kernel's CONFIG_CLONE_* settings.
+         * Microblaze is further special in that it uses a sixth
+         * implicit argument to clone for the TLS pointer.
+         */
+#if defined(TARGET_MICROBLAZE)
         ret = get_errno(do_fork(cpu_env, arg1, arg2, arg4, arg6, arg5));
-#elif defined(TARGET_S390X)
+#elif defined(TARGET_CLONE_BACKWARDS)
+        ret = get_errno(do_fork(cpu_env, arg1, arg2, arg3, arg4, arg5));
+#elif defined(TARGET_CLONE_BACKWARDS2)
         ret = get_errno(do_fork(cpu_env, arg2, arg1, arg3, arg5, arg4));
 #else
-        ret = get_errno(do_fork(cpu_env, arg1, arg2, arg3, arg4, arg5));
+        ret = get_errno(do_fork(cpu_env, arg1, arg2, arg3, arg5, arg4));
 #endif
         break;
 #ifdef __NR_exit_group