diff options
| author | Denys Vlasenko <dvlasenk@redhat.com> | 2015-07-03 23:19:02 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-07-06 15:56:50 +0300 |
| commit | c73e36b775a777abd67a1e15481923fcbd2040e1 (patch) | |
| tree | 73eaac0ac71250279e146f17b6db0a7b53a813be /arch/x86/entry | |
| parent | 1c4c7159ed2468f3ac4ce5a7f08d79663d381a93 (diff) | |
| download | linux-c73e36b775a777abd67a1e15481923fcbd2040e1.tar.xz | |
x86/asm/entry/32: Replace RESTORE_RSI_RDI with open-coded 32-bit reads
This doesn't change much, but uses shorter 32-bit insns:
-48 8b 74 24 68 mov 0x68(%rsp),%rsi
-48 8b 7c 24 70 mov 0x70(%rsp),%rdi
-48 8b 54 24 60 mov 0x60(%rsp),%rdx
+8b 54 24 60 mov 0x60(%rsp),%edx
+8b 74 24 68 mov 0x68(%rsp),%esi
+8b 7c 24 70 mov 0x70(%rsp),%edi
and does the loads in pt_regs order.
Since these are the only uses of RESTORE_RSI_RDI[_RDX], drop
these macros.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1435954742-2545-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/calling.h | 6 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64_compat.S | 7 |
2 files changed, 5 insertions, 8 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index f4e6308c4200..519207f2ee76 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -193,12 +193,6 @@ For 32-bit we have the following conventions - kernel is built with .macro RESTORE_C_REGS_EXCEPT_RCX_R11 RESTORE_C_REGS_HELPER 1,0,0,1,1 .endm - .macro RESTORE_RSI_RDI - RESTORE_C_REGS_HELPER 0,0,0,0,0 - .endm - .macro RESTORE_RSI_RDI_RDX - RESTORE_C_REGS_HELPER 0,0,0,0,1 - .endm .macro REMOVE_PT_GPREGS_FROM_STACK addskip=0 subq $-(15*8+\addskip), %rsp diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index bb187a6a877c..b868cfc72985 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -140,7 +140,8 @@ sysexit_from_sys_call: */ andl $~TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS) movl RIP(%rsp), %ecx /* User %eip */ - RESTORE_RSI_RDI + movl RSI(%rsp), %esi + movl RDI(%rsp), %edi xorl %edx, %edx /* Do not leak kernel information */ xorq %r8, %r8 xorq %r9, %r9 @@ -366,7 +367,9 @@ cstar_dispatch: sysretl_from_sys_call: andl $~TS_COMPAT, ASM_THREAD_INFO(TI_status, %rsp, SIZEOF_PTREGS) - RESTORE_RSI_RDI_RDX + movl RDX(%rsp), %edx + movl RSI(%rsp), %esi + movl RDI(%rsp), %edi movl RIP(%rsp), %ecx movl EFLAGS(%rsp), %r11d xorq %r10, %r10 |