x86/asm/crypto: Simplify stack usage in sha-mb functions

sha1_mb_mgr_flush_avx2() and sha1_mb_mgr_submit_avx2() both allocate a
lot of stack space which is never used.  Also, many of the registers
being saved aren't being clobbered so there's no need to save them.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/9402e4d87580d6b2376ed95f67b84bdcce3c830e.1453405861.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S b/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S
index 85c4e1cf717235b8fc1cafcef458c386b84b8f66..672eaeb258a503d9671560b1cff11e599721271b 100644 (file)
--- a/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S
+++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S
@@ -86,16 +86,6 @@
 #define extra_blocks    %arg2
 #define p               %arg2
 
-
-# STACK_SPACE needs to be an odd multiple of 8
-_XMM_SAVE_SIZE  = 10*16
-_GPR_SAVE_SIZE  = 8*8
-_ALIGN_SIZE     = 8
-
-_XMM_SAVE       = 0
-_GPR_SAVE       = _XMM_SAVE + _XMM_SAVE_SIZE
-STACK_SPACE     = _GPR_SAVE + _GPR_SAVE_SIZE + _ALIGN_SIZE
-
 .macro LABEL prefix n
 \prefix\n\():
 .endm
@@ -113,16 +103,7 @@ offset = \_offset
 # JOB* sha1_mb_mgr_flush_avx2(MB_MGR *state)
 # arg 1 : rcx : state
 ENTRY(sha1_mb_mgr_flush_avx2)
-       mov     %rsp, %r10
-       sub     $STACK_SPACE, %rsp
-       and     $~31, %rsp
-       mov     %rbx, _GPR_SAVE(%rsp)
-       mov     %r10, _GPR_SAVE+8*1(%rsp) #save rsp
-       mov     %rbp, _GPR_SAVE+8*3(%rsp)
-       mov     %r12, _GPR_SAVE+8*4(%rsp)
-       mov     %r13, _GPR_SAVE+8*5(%rsp)
-       mov     %r14, _GPR_SAVE+8*6(%rsp)
-       mov     %r15, _GPR_SAVE+8*7(%rsp)
+       push    %rbx
 
        # If bit (32+3) is set, then all lanes are empty
        mov     _unused_lanes(state), unused_lanes
@@ -230,16 +211,7 @@ len_is_0:
        mov     tmp2_w, offset(job_rax)
 
 return:
-
-       mov     _GPR_SAVE(%rsp), %rbx
-       mov     _GPR_SAVE+8*1(%rsp), %r10 #saved rsp
-       mov     _GPR_SAVE+8*3(%rsp), %rbp
-       mov     _GPR_SAVE+8*4(%rsp), %r12
-       mov     _GPR_SAVE+8*5(%rsp), %r13
-       mov     _GPR_SAVE+8*6(%rsp), %r14
-       mov     _GPR_SAVE+8*7(%rsp), %r15
-       mov     %r10, %rsp
-
+       pop     %rbx
        ret
 
 return_null:

diff --git a/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S b/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S
index 2ab9560b53c84db34f32334a036111ab3e601ef7..a5a14c62d843262660067837e31e13e826a71d82 100644 (file)
--- a/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S
+++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S
@@ -94,25 +94,12 @@ DWORD_tmp   = %r9d
 
 lane_data       = %r10
 
-# STACK_SPACE needs to be an odd multiple of 8
-STACK_SPACE     = 8*8 + 16*10 + 8
-
 # JOB* submit_mb_mgr_submit_avx2(MB_MGR *state, job_sha1 *job)
 # arg 1 : rcx : state
 # arg 2 : rdx : job
 ENTRY(sha1_mb_mgr_submit_avx2)
-
-       mov     %rsp, %r10
-       sub     $STACK_SPACE, %rsp
-       and     $~31, %rsp
-
-       mov     %rbx, (%rsp)
-       mov     %r10, 8*2(%rsp) #save old rsp
-       mov     %rbp, 8*3(%rsp)
-       mov     %r12, 8*4(%rsp)
-       mov     %r13, 8*5(%rsp)
-       mov     %r14, 8*6(%rsp)
-       mov     %r15, 8*7(%rsp)
+       push    %rbx
+       push    %rbp
 
        mov     _unused_lanes(state), unused_lanes
        mov     unused_lanes, lane
@@ -203,16 +190,8 @@ len_is_0:
        movl    DWORD_tmp, _result_digest+1*16(job_rax)
 
 return:
-
-       mov     (%rsp), %rbx
-       mov     8*2(%rsp), %r10 #save old rsp
-       mov     8*3(%rsp), %rbp
-       mov     8*4(%rsp), %r12
-       mov     8*5(%rsp), %r13
-       mov     8*6(%rsp), %r14
-       mov     8*7(%rsp), %r15
-       mov     %r10, %rsp
-
+       pop     %rbp
+       pop     %rbx
        ret
 
 return_null: