* swsusp: fix x86-64 [was Re: swsusp: solving build issue leads to crash on x86-64]
2004-09-16 19:22 swsusp: solving build issue leads to crash on x86-64 Pavel Machek
@ 2004-09-16 20:32 ` Pavel Machek
0 siblings, 0 replies; 2+ messages in thread
From: Pavel Machek @ 2004-09-16 20:32 UTC (permalink / raw)
To: JBeulich, Andrew Morton; +Cc: kernel list, Patrick Mochel, seife
Hi!
I could not get accessing __nosave variables from assembly right, so I
simply eliminated memory accesses and cleaned up code at the same
time. Please apply,
Pavel
> Do you remember that build issue, where you needed to added ', "aw"'
> to make linker happy? Well, too late I found that it breaks swsusp in
> quite a ugly way. Try it on x86-64: it works without "aw", breaks with
> it.
>
> I'm doing this for now. I'll probably just rewrite assemlby not to
> require those variables, but understanding what went wrong there would
> be welcome.
>
> # .section .data.nosave, "aw"
> .section .data.nosave
> .align 8
> loop:
> .quad 0
> loop2:
> .quad 0
> .previous
--- linux-mm/arch/x86_64/kernel/suspend_asm.S 2004-09-15 12:58:08.000000000 +0200
+++ linux64/arch/x86_64/kernel/suspend_asm.S 2004-09-16 22:20:21.000000000 +0200
@@ -39,29 +39,28 @@
/* set up cr3 */
leaq init_level4_pgt(%rip),%rax
subq $__START_KERNEL_map,%rax
- movq %rax,%cr3
+ movq %rax,%cr3
movq mmu_cr4_features(%rip), %rax
movq %rax, %rdx
-
andq $~(1<<7), %rdx # PGE
- movq %rdx, %cr4; # turn off PGE
- movq %cr3, %rcx; # flush TLB
- movq %rcx, %cr3;
- movq %rax, %cr4; # turn PGE back on
+ movq %rdx, %cr4; # turn off PGE
+ movq %cr3, %rcx; # flush TLB
+ movq %rcx, %cr3;
+ movq %rax, %cr4; # turn PGE back on
movl nr_copy_pages(%rip), %eax
xorl %ecx, %ecx
- movq $0, loop(%rip)
+ movq $0, %r10
testl %eax, %eax
- je .L108
+ jz done
.L105:
xorl %esi, %esi
- movq $0, loop2(%rip)
+ movq $0, %r11
jmp .L104
.p2align 4,,7
-.L111:
- movq loop(%rip), %rcx
+copy_one_page:
+ movq %r10, %rcx
.L104:
movq pagedir_nosave(%rip), %rdx
movq %rcx, %rax
@@ -71,27 +70,26 @@
movzbl (%rsi,%rax), %eax
movb %al, (%rsi,%rcx)
- movq %cr3, %rax; # flush TLB
- movq %rax, %cr3;
+ movq %cr3, %rax; # flush TLB
+ movq %rax, %cr3;
- movq loop2(%rip), %rax
+ movq %r11, %rax
incq %rax
cmpq $4095, %rax
movq %rax, %rsi
- movq %rax, loop2(%rip)
- jbe .L111
- movq loop(%rip), %rax
+ movq %rax, %r11
+ jbe copy_one_page
+ movq %r10, %rax
incq %rax
movq %rax, %rcx
- movq %rax, loop(%rip)
+ movq %rax, %r10
mov nr_copy_pages(%rip), %eax
cmpq %rax, %rcx
jb .L105
-.L108:
- .align 4
+done:
movl $24, %eax
-
- movl %eax, %ds
+ movl %eax, %ds
+
movq saved_context_esp(%rip), %rsp
movq saved_context_ebp(%rip), %rbp
movq saved_context_eax(%rip), %rax
@@ -111,11 +109,3 @@
pushq saved_context_eflags(%rip) ; popfq
call swsusp_restore
ret
-
- .section .data.nosave, "aw"
- .align 8
-loop:
- .quad 0
-loop2:
- .quad 0
- .previous
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!
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