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| author | Andy Lutomirski <luto@kernel.org> | 2018-04-04 00:39:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-04-09 18:23:50 +0200 |
| commit | 071ccc966ba5db1ac8f5c24b0faebb37698f68db (patch) | |
| tree | 47e024d956113461ee2ccab53115f4efd18ff432 | |
| parent | x86/uapi: Fix asm/bootparam.h userspace compilation errors (diff) | |
| download | linux-071ccc966ba5db1ac8f5c24b0faebb37698f68db.tar.xz linux-071ccc966ba5db1ac8f5c24b0faebb37698f68db.zip | |
x86/entry/64: Drop idtentry's manual stack switch for user entries
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 the following commit:
7f2590a110b8 ("x86/entry/64: Use a per-CPU trampoline stack for IDT entries")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/90aab80c1f906e70742eaa4512e3c9b5e62d59d4.1522794757.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/entry/entry_64.S | 4 |
1 files 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 |