diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-18 01:11:58 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-11-28 21:49:03 -0500 |
| commit | e0e431aa45416982eb3fddf34cedc72f1c3b3ce3 (patch) | |
| tree | 10f3e3009387881a3c4a209b9d72c453aae865a1 /arch/alpha/kernel/entry.S | |
| parent | 2b067fc9dd143be5e0ee94bae0fbd28ea0a407f8 (diff) | |
alpha: simplify fork and friends
* no need to restore everything from switch_stack when we only need $26
* no need to pass current_pt_regs() manually, we can just as easily
calculate it in alpha_clone/alpha_vfork ($8 + constant)
* interpretation of zero usp as "use the parent's" is simpler in copy_thread();
let fork and vfork just pass 0.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/alpha/kernel/entry.S')
| -rw-r--r-- | arch/alpha/kernel/entry.S | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index a7607832dd4f..cc6d34e9e2ea 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -617,7 +617,6 @@ ret_from_kernel_thread: .ent sys_fork sys_fork: .prologue 0 - mov $sp, $21 bsr $1, do_switch_stack bis $31, SIGCHLD, $16 mov $31, $17 @@ -625,7 +624,9 @@ sys_fork: mov $31, $19 mov $31, $20 jsr $26, alpha_clone - bsr $1, undo_switch_stack +fork_out: + ldq $26, 56($sp) + lda $sp, SWITCH_STACK_SIZE($sp) ret .end sys_fork @@ -634,12 +635,10 @@ sys_fork: .ent sys_clone sys_clone: .prologue 0 - mov $sp, $21 bsr $1, do_switch_stack /* $16, $17, $18, $19, $20 come from the user. */ - jsr $26, alpha_clone - bsr $1, undo_switch_stack - ret + lda $26, fork_out + jsr $31, alpha_clone .end sys_clone .align 4 @@ -647,11 +646,9 @@ sys_clone: .ent sys_vfork sys_vfork: .prologue 0 - mov $sp, $16 bsr $1, do_switch_stack - jsr $26, alpha_vfork - bsr $1, undo_switch_stack - ret + lda $26, fork_out + jsr $31, alpha_vfork .end sys_vfork .align 4 |