[PATCH] x86/entry/64: Drop idtentry's manual stack switch for user entries

[Andy Lutomirski]

For non-paranoid entries, idtentry knows how to switch from the
kernel stack to the user stack, as does error_entry.  This results
in pointless duplication and code bloat.  Make idtentry stop
thinking about stacks for non-paranoid entries.

This reduces text size by 5377 bytes.

This goes back to commit 7f2590a110b8 ("x86/entry/64: Use a per-CPU
trampoline stack for IDT entries").

Signed-off-by: Andy Lutomirski <l...@kernel.org>
---

Hi all-

I have more cleanups in the works, but this is enough of I win by itself
that I wanted to get it out there.

 arch/x86/entry/entry_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 9b114675fbc0..e237913a056b 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -908,7 +908,7 @@ ENTRY(\sym)
        pushq   $-1                             /* ORIG_RAX: no syscall to 
restart */
        .endif
 
-       .if \paranoid < 2
+       .if \paranoid == 1
        testb   $3, CS-ORIG_RAX(%rsp)           /* If coming from userspace, 
switch stacks */
        jnz     .Lfrom_usermode_switch_stack_\@
        .endif
@@ -955,7 +955,7 @@ ENTRY(\sym)
        jmp     error_exit
        .endif
 
-       .if \paranoid < 2
+       .if \paranoid == 1
        /*
         * Entry from userspace.  Switch stacks and treat it
         * as a normal entry.  This means that paranoid handlers
-- 
2.14.3