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authorAl Viro <viro@zeniv.linux.org.uk>2012-09-30 00:27:40 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-14 19:33:54 -0400
commitc19e6d67e4be16e20ff90f0baa98b16d926d23a5 (patch)
treec5421d406815c7341c26179acf8b71bdaf251a18
parentc4aee363af2a81f9726c5fa13e136ebaf02852bd (diff)
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ia64: don't mess with ar_bspstore in kernel_thread()
the only thing we use that for is in copy_thread(), where the way we set it will result in rbs_size being 0. Just move that calculating rbs_size and copying rbs to non-kernel-thread side of if (user_mode(regs)) in copy_thread() and set rbs_size to 0 on kernel thread side. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--arch/ia64/kernel/process.c9
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 63a77b8b5cfa..6a48775d9363 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -411,12 +411,11 @@ copy_thread(unsigned long clone_flags,
rbs = (unsigned long) current + IA64_RBS_OFFSET;
child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
- rbs_size = stack->ar_bspstore - rbs;
-
- /* copy the parent's register backing store to the child: */
- memcpy((void *) child_rbs, (void *) rbs, rbs_size);
if (likely(user_mode(child_ptregs))) {
+ /* copy the parent's register backing store to the child: */
+ rbs_size = stack->ar_bspstore - rbs;
+ memcpy((void *) child_rbs, (void *) rbs, rbs_size);
if (clone_flags & CLONE_SETTLS)
child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */
if (user_stack_base) {
@@ -433,6 +432,7 @@ copy_thread(unsigned long clone_flags,
* been taken care of by the caller of sys_clone()
* already.
*/
+ rbs_size = 0;
child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */
child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
}
@@ -637,7 +637,6 @@ kernel_thread (int (*fn)(void *), void *arg, unsigned long flags)
regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
regs.pt.cr_ifs = 1UL << 63; /* mark as valid, empty frame */
regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR);
- regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET;
regs.sw.pr = (1 << PRED_KERNEL_STACK);
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs.pt, 0, NULL, NULL);
}