Signed-off-by: Nathan Lynch <ntl@xxxxxxxxx>
---
clone_ppc.c | 43 ++++++++++++++++++++++++++++++++
clone_ppc_.S | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 120 insertions(+), 0 deletions(-)
diff --git a/clone_ppc.c b/clone_ppc.c
index 49797fd..c9eee8b 100644
--- a/clone_ppc.c
+++ b/clone_ppc.c
@@ -56,3 +56,46 @@ int clone_with_pids(int (*fn)(void *), void *child_stack, int flags,
}
#endif
+
+#include "eclone.h"
+
+extern int __eclone(int (*fn)(void *arg),
+ void *child_sp,
+ int flags,
+ void *fn_arg,
+ struct clone_args *args,
+ size_t args_size,
+ pid_t *pids);
+
+int eclone(int (*fn)(void *), void *fn_arg, int clone_flags_low,
+ struct clone_args *clone_args, pid_t *pids)
+{
+ struct clone_args my_args;
+ unsigned long child_sp;
+ int newpid;
+
+ if (clone_args->child_stack)
+ child_sp = clone_args->child_stack +
+ clone_args->child_stack_size - 1;
+ else
+ child_sp = 0;
+
+ my_args = *clone_args;
+ my_args.child_stack = child_sp;
+ my_args.child_stack_size = 0;
+
+ newpid = __eclone(fn,
+ (void *)child_sp,
+ clone_flags_low,
+ fn_arg,
+ &my_args,
+ sizeof(my_args),
+ pids);
+
+ if (newpid < 0) {
+ errno = -newpid;
+ newpid = -1;
+ }
+
+ return newpid;
+}
diff --git a/clone_ppc_.S b/clone_ppc_.S
index cb3e053..fa89c31 100644
--- a/clone_ppc_.S
+++ b/clone_ppc_.S
@@ -88,3 +88,80 @@ parent:
neg r3,r3
blr
+#ifndef __NR_eclone
+#define __NR_eclone 323
+#endif
+
+/* int [r3] eclone(int (*fn)(void *arg) [r3],
+ * void *child_sp [r4],
+ * int flags [r5],
+ * void *fn_arg [r6],
+ * struct clone_args *args [r7],
+ * size_t args_size [r8],
+ * pid_t *pids [r9]);
+ * Creates a child task with the pids specified by pids.
+ * Returns to parent only, child execution and exit is handled here.
+ * On error, returns negated errno. On success, returns the pid of the child
+ * created.
+ */
+
+.globl __eclone
+__eclone:
+
+ /* No argument validation. */
+
+ /* Set up parent's stack frame. */
+ stwu r1,-32(r1)
+
+ /* Save non-volatiles (r28-r31) which we plan to use. */
+ stmw r28,16(r1)
+
+ /* Set up child's stack frame. */
+ clrrwi r4,r4,4
+ li r0,0
+ stw r0,-16(r4)
+
+ /* Save fn, stack pointer, flags, and fn_arg across system call. */
+ mr r28,r3
+ mr r29,r4
+ mr r30,r5
+ mr r31,r6
+
+ /* Set up arguments for system call. */
+ mr r3,r5 /* flags */
+ mr r4,r7 /* clone_args */
+ mr r5,r8 /* clone_args' size */
+ mr r6,r9 /* pids */
+
+ /* Do the system call */
+ li r0,__NR_eclone
+ sc
+
+ /* Parent or child? */
+ cmpwi cr1,r3,0
+ crandc 4*cr1+eq,4*cr1+eq,4*cr0+so
+ bne cr1,eclone_parent
+
+ /* Child. Call fn. */
+ mtctr r28
+ mr r3,r31
+ bctrl
+
+ /* Assume result of fn in r3 and exit. */
+ li r0,__NR_exit
+ sc
+
+eclone_parent:
+ /* Restore non-volatiles. */
+ lmw r28,16(r1)
+
+ addi r1,r1,32
+
+ /* Return to caller on success. */
+ bnslr
+
+ /* Handle error. Negate the return value to signal an error
+ * to the caller, which must set errno.
+ */
+ neg r3,r3
+ blr
--
1.6.2.5
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