1 files changed, 417 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/winfixup.S b/arch/sparc64/kernel/winfixup.S
new file mode 100644
index 000000000000..dfbc7e0dcf70
--- /dev/null
+++ b/arch/sparc64/kernel/winfixup.S
@@ -0,0 +1,417 @@
+/* $Id: winfixup.S,v 1.30 2002/02/09 19:49:30 davem Exp $
+ *
+ * winfixup.S: Handle cases where user stack pointer is found to be bogus.
+ *
+ * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#include <asm/asi.h>
+#include <asm/head.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/processor.h>
+#include <asm/spitfire.h>
+#include <asm/thread_info.h>
+
+	.text
+
+set_pcontext:
+cplus_winfixup_insn_1:
+	sethi	%hi(0), %l1
+	mov	PRIMARY_CONTEXT, %g1
+	sllx	%l1, 32, %l1
+cplus_winfixup_insn_2:
+	sethi	%hi(0), %g2
+	or	%l1, %g2, %l1
+	stxa	%l1, [%g1] ASI_DMMU
+	flush	%g6
+	retl
+	 nop
+
+cplus_wfinsn_1:
+	sethi	%uhi(CTX_CHEETAH_PLUS_NUC), %l1
+cplus_wfinsn_2:
+	sethi	%hi(CTX_CHEETAH_PLUS_CTX0), %g2
+
+	.align	32
+
+	/* Here are the rules, pay attention.
+	 *
+	 * The kernel is disallowed from touching user space while
+	 * the trap level is greater than zero, except for from within
+	 * the window spill/fill handlers.  This must be followed
+	 * so that we can easily detect the case where we tried to
+	 * spill/fill with a bogus (or unmapped) user stack pointer.
+	 *
+	 * These are layed out in a special way for cache reasons,
+	 * don't touch...
+	 */
+	.globl	fill_fixup, spill_fixup
+fill_fixup:
+	rdpr		%tstate, %g1
+	andcc		%g1, TSTATE_PRIV, %g0
+	or		%g4, FAULT_CODE_WINFIXUP, %g4
+	be,pt		%xcc, window_scheisse_from_user_common
+	 and		%g1, TSTATE_CWP, %g1
+
+	/* This is the extremely complex case, but it does happen from
+	 * time to time if things are just right.  Essentially the restore
+	 * done in rtrap right before going back to user mode, with tl=1
+	 * and that levels trap stack registers all setup, took a fill trap,
+	 * the user stack was not mapped in the tlb, and tlb miss occurred,
+	 * the pte found was not valid, and a simple ref bit watch update
+	 * could not satisfy the miss, so we got here.
+	 *
+	 * We must carefully unwind the state so we get back to tl=0, preserve
+	 * all the register values we were going to give to the user.  Luckily
+	 * most things are where they need to be, we also have the address
+	 * which triggered the fault handy as well.
+	 *
+	 * Also note that we must preserve %l5 and %l6.  If the user was
+	 * returning from a system call, we must make it look this way
+	 * after we process the fill fault on the users stack.
+	 *
+	 * First, get into the window where the original restore was executed.
+	 */
+
+	rdpr		%wstate, %g2			! Grab user mode wstate.
+	wrpr		%g1, %cwp			! Get into the right window.
+	sll		%g2, 3, %g2			! NORMAL-->OTHER
+
+	wrpr		%g0, 0x0, %canrestore		! Standard etrap stuff.
+	wrpr		%g2, 0x0, %wstate		! This must be consistent.
+	wrpr		%g0, 0x0, %otherwin		! We know this.
+	call		set_pcontext			! Change contexts...
+	 nop
+	rdpr		%pstate, %l1			! Prepare to change globals.
+	mov		%g6, %o7			! Get current.
+
+	andn		%l1, PSTATE_MM, %l1		! We want to be in RMO
+	stb		%g4, [%g6 + TI_FAULT_CODE]
+	stx		%g5, [%g6 + TI_FAULT_ADDR]
+	wrpr		%g0, 0x0, %tl			! Out of trap levels.
+	wrpr		%l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
+	mov		%o7, %g6
+	ldx		[%g6 + TI_TASK], %g4
+#ifdef CONFIG_SMP
+	mov		TSB_REG, %g1
+	ldxa		[%g1] ASI_IMMU, %g5
+#endif
+
+	/* This is the same as below, except we handle this a bit special
+	 * since we must preserve %l5 and %l6, see comment above.
+	 */
+	call		do_sparc64_fault
+	 add		%sp, PTREGS_OFF, %o0
+	ba,pt		%xcc, rtrap
+	 nop						! yes, nop is correct
+
+	/* Be very careful about usage of the alternate globals here.
+	 * You cannot touch %g4/%g5 as that has the fault information
+	 * should this be from usermode.  Also be careful for the case
+	 * where we get here from the save instruction in etrap.S when
+	 * coming from either user or kernel (does not matter which, it
+	 * is the same problem in both cases).  Essentially this means
+	 * do not touch %g7 or %g2 so we handle the two cases fine.
+	 */
+spill_fixup:
+	ldx		[%g6 + TI_FLAGS], %g1
+	andcc		%g1, _TIF_32BIT, %g0
+	ldub		[%g6 + TI_WSAVED], %g1
+
+	sll		%g1, 3, %g3
+	add		%g6, %g3, %g3
+	stx		%sp, [%g3 + TI_RWIN_SPTRS]
+	sll		%g1, 7, %g3
+	bne,pt		%xcc, 1f
+	 add		%g6, %g3, %g3
+	stx		%l0, [%g3 + TI_REG_WINDOW + 0x00]
+	stx		%l1, [%g3 + TI_REG_WINDOW + 0x08]
+
+	stx		%l2, [%g3 + TI_REG_WINDOW + 0x10]
+	stx		%l3, [%g3 + TI_REG_WINDOW + 0x18]
+	stx		%l4, [%g3 + TI_REG_WINDOW + 0x20]
+	stx		%l5, [%g3 + TI_REG_WINDOW + 0x28]
+	stx		%l6, [%g3 + TI_REG_WINDOW + 0x30]
+	stx		%l7, [%g3 + TI_REG_WINDOW + 0x38]
+	stx		%i0, [%g3 + TI_REG_WINDOW + 0x40]
+	stx		%i1, [%g3 + TI_REG_WINDOW + 0x48]
+
+	stx		%i2, [%g3 + TI_REG_WINDOW + 0x50]
+	stx		%i3, [%g3 + TI_REG_WINDOW + 0x58]
+	stx		%i4, [%g3 + TI_REG_WINDOW + 0x60]
+	stx		%i5, [%g3 + TI_REG_WINDOW + 0x68]
+	stx		%i6, [%g3 + TI_REG_WINDOW + 0x70]
+	b,pt		%xcc, 2f
+	 stx		%i7, [%g3 + TI_REG_WINDOW + 0x78]
+1:	stw		%l0, [%g3 + TI_REG_WINDOW + 0x00]
+
+	stw		%l1, [%g3 + TI_REG_WINDOW + 0x04]
+	stw		%l2, [%g3 + TI_REG_WINDOW + 0x08]
+	stw		%l3, [%g3 + TI_REG_WINDOW + 0x0c]
+	stw		%l4, [%g3 + TI_REG_WINDOW + 0x10]
+	stw		%l5, [%g3 + TI_REG_WINDOW + 0x14]
+	stw		%l6, [%g3 + TI_REG_WINDOW + 0x18]
+	stw		%l7, [%g3 + TI_REG_WINDOW + 0x1c]
+	stw		%i0, [%g3 + TI_REG_WINDOW + 0x20]
+
+	stw		%i1, [%g3 + TI_REG_WINDOW + 0x24]
+	stw		%i2, [%g3 + TI_REG_WINDOW + 0x28]
+	stw		%i3, [%g3 + TI_REG_WINDOW + 0x2c]
+	stw		%i4, [%g3 + TI_REG_WINDOW + 0x30]
+	stw		%i5, [%g3 + TI_REG_WINDOW + 0x34]
+	stw		%i6, [%g3 + TI_REG_WINDOW + 0x38]
+	stw		%i7, [%g3 + TI_REG_WINDOW + 0x3c]
+2:	add		%g1, 1, %g1
+
+	stb		%g1, [%g6 + TI_WSAVED]
+	rdpr		%tstate, %g1
+	andcc		%g1, TSTATE_PRIV, %g0
+	saved
+	and		%g1, TSTATE_CWP, %g1
+	be,pn		%xcc, window_scheisse_from_user_common
+	 mov		FAULT_CODE_WRITE | FAULT_CODE_DTLB | FAULT_CODE_WINFIXUP, %g4
+	retry
+
+window_scheisse_from_user_common:
+	stb		%g4, [%g6 + TI_FAULT_CODE]
+	stx		%g5, [%g6 + TI_FAULT_ADDR]
+	wrpr		%g1, %cwp
+	ba,pt		%xcc, etrap
+	 rd		%pc, %g7
+	call		do_sparc64_fault
+	 add		%sp, PTREGS_OFF, %o0
+	ba,a,pt		%xcc, rtrap_clr_l6
+
+	.globl		winfix_mna, fill_fixup_mna, spill_fixup_mna
+winfix_mna:
+	andn		%g3, 0x7f, %g3
+	add		%g3, 0x78, %g3
+	wrpr		%g3, %tnpc
+	done
+fill_fixup_mna:
+	rdpr		%tstate, %g1
+	andcc		%g1, TSTATE_PRIV, %g0
+	be,pt		%xcc, window_mna_from_user_common
+	 and		%g1, TSTATE_CWP, %g1
+
+	/* Please, see fill_fixup commentary about why we must preserve
+	 * %l5 and %l6 to preserve absolute correct semantics.
+	 */
+	rdpr		%wstate, %g2			! Grab user mode wstate.
+	wrpr		%g1, %cwp			! Get into the right window.
+	sll		%g2, 3, %g2			! NORMAL-->OTHER
+	wrpr		%g0, 0x0, %canrestore		! Standard etrap stuff.
+
+	wrpr		%g2, 0x0, %wstate		! This must be consistent.
+	wrpr		%g0, 0x0, %otherwin		! We know this.
+	call		set_pcontext			! Change contexts...
+	 nop
+	rdpr		%pstate, %l1			! Prepare to change globals.
+	mov		%g4, %o2			! Setup args for
+	mov		%g5, %o1			! final call to mem_address_unaligned.
+	andn		%l1, PSTATE_MM, %l1		! We want to be in RMO
+
+	mov		%g6, %o7			! Stash away current.
+	wrpr		%g0, 0x0, %tl			! Out of trap levels.
+	wrpr		%l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
+	mov		%o7, %g6			! Get current back.
+	ldx		[%g6 + TI_TASK], %g4		! Finish it.
+#ifdef CONFIG_SMP
+	mov		TSB_REG, %g1
+	ldxa		[%g1] ASI_IMMU, %g5
+#endif
+	call		mem_address_unaligned
+	 add		%sp, PTREGS_OFF, %o0
+
+	b,pt		%xcc, rtrap
+	 nop						! yes, the nop is correct
+spill_fixup_mna:
+	ldx		[%g6 + TI_FLAGS], %g1
+	andcc		%g1, _TIF_32BIT, %g0
+	ldub		[%g6 + TI_WSAVED], %g1
+	sll		%g1, 3, %g3
+	add		%g6, %g3, %g3
+	stx		%sp, [%g3 + TI_RWIN_SPTRS]
+
+	sll		%g1, 7, %g3
+	bne,pt		%xcc, 1f
+	 add		%g6, %g3, %g3
+	stx		%l0, [%g3 + TI_REG_WINDOW + 0x00]
+	stx		%l1, [%g3 + TI_REG_WINDOW + 0x08]
+	stx		%l2, [%g3 + TI_REG_WINDOW + 0x10]
+	stx		%l3, [%g3 + TI_REG_WINDOW + 0x18]
+	stx		%l4, [%g3 + TI_REG_WINDOW + 0x20]
+
+	stx		%l5, [%g3 + TI_REG_WINDOW + 0x28]
+	stx		%l6, [%g3 + TI_REG_WINDOW + 0x30]
+	stx		%l7, [%g3 + TI_REG_WINDOW + 0x38]
+	stx		%i0, [%g3 + TI_REG_WINDOW + 0x40]
+	stx		%i1, [%g3 + TI_REG_WINDOW + 0x48]
+	stx		%i2, [%g3 + TI_REG_WINDOW + 0x50]
+	stx		%i3, [%g3 + TI_REG_WINDOW + 0x58]
+	stx		%i4, [%g3 + TI_REG_WINDOW + 0x60]
+
+	stx		%i5, [%g3 + TI_REG_WINDOW + 0x68]
+	stx		%i6, [%g3 + TI_REG_WINDOW + 0x70]
+	stx		%i7, [%g3 + TI_REG_WINDOW + 0x78]
+	b,pt		%xcc, 2f
+	 add		%g1, 1, %g1
+1:	std		%l0, [%g3 + TI_REG_WINDOW + 0x00]
+	std		%l2, [%g3 + TI_REG_WINDOW + 0x08]
+	std		%l4, [%g3 + TI_REG_WINDOW + 0x10]
+
+	std		%l6, [%g3 + TI_REG_WINDOW + 0x18]
+	std		%i0, [%g3 + TI_REG_WINDOW + 0x20]
+	std		%i2, [%g3 + TI_REG_WINDOW + 0x28]
+	std		%i4, [%g3 + TI_REG_WINDOW + 0x30]
+	std		%i6, [%g3 + TI_REG_WINDOW + 0x38]
+	add		%g1, 1, %g1
+2:	stb		%g1, [%g6 + TI_WSAVED]
+	rdpr		%tstate, %g1
+
+	andcc		%g1, TSTATE_PRIV, %g0
+	saved
+	be,pn		%xcc, window_mna_from_user_common
+	 and		%g1, TSTATE_CWP, %g1
+	retry
+window_mna_from_user_common:
+	wrpr		%g1, %cwp
+	sethi		%hi(109f), %g7
+	ba,pt		%xcc, etrap
+109:	 or		%g7, %lo(109b), %g7
+	mov		%l4, %o2
+	mov		%l5, %o1
+	call		mem_address_unaligned
+	 add		%sp, PTREGS_OFF, %o0
+	ba,pt		%xcc, rtrap
+	 clr		%l6
+	
+	/* These are only needed for 64-bit mode processes which
+	 * put their stack pointer into the VPTE area and there
+	 * happens to be a VPTE tlb entry mapped there during
+	 * a spill/fill trap to that stack frame.
+	 */
+	.globl		winfix_dax, fill_fixup_dax, spill_fixup_dax
+winfix_dax:
+	andn		%g3, 0x7f, %g3
+	add		%g3, 0x74, %g3
+	wrpr		%g3, %tnpc
+	done
+fill_fixup_dax:
+	rdpr		%tstate, %g1
+	andcc		%g1, TSTATE_PRIV, %g0
+	be,pt		%xcc, window_dax_from_user_common
+	 and		%g1, TSTATE_CWP, %g1
+
+	/* Please, see fill_fixup commentary about why we must preserve
+	 * %l5 and %l6 to preserve absolute correct semantics.
+	 */
+	rdpr		%wstate, %g2			! Grab user mode wstate.
+	wrpr		%g1, %cwp			! Get into the right window.
+	sll		%g2, 3, %g2			! NORMAL-->OTHER
+	wrpr		%g0, 0x0, %canrestore		! Standard etrap stuff.
+
+	wrpr		%g2, 0x0, %wstate		! This must be consistent.
+	wrpr		%g0, 0x0, %otherwin		! We know this.
+	call		set_pcontext			! Change contexts...
+	 nop
+	rdpr		%pstate, %l1			! Prepare to change globals.
+	mov		%g4, %o1			! Setup args for
+	mov		%g5, %o2			! final call to data_access_exception.
+	andn		%l1, PSTATE_MM, %l1		! We want to be in RMO
+
+	mov		%g6, %o7			! Stash away current.
+	wrpr		%g0, 0x0, %tl			! Out of trap levels.
+	wrpr		%l1, (PSTATE_IE | PSTATE_AG | PSTATE_RMO), %pstate
+	mov		%o7, %g6			! Get current back.
+	ldx		[%g6 + TI_TASK], %g4		! Finish it.
+#ifdef CONFIG_SMP
+	mov		TSB_REG, %g1
+	ldxa		[%g1] ASI_IMMU, %g5
+#endif
+	call		data_access_exception
+	 add		%sp, PTREGS_OFF, %o0
+
+	b,pt		%xcc, rtrap
+	 nop						! yes, the nop is correct
+spill_fixup_dax:
+	ldx		[%g6 + TI_FLAGS], %g1
+	andcc		%g1, _TIF_32BIT, %g0
+	ldub		[%g6 + TI_WSAVED], %g1
+	sll		%g1, 3, %g3
+	add		%g6, %g3, %g3
+	stx		%sp, [%g3 + TI_RWIN_SPTRS]
+
+	sll		%g1, 7, %g3
+	bne,pt		%xcc, 1f
+	 add		%g6, %g3, %g3
+	stx		%l0, [%g3 + TI_REG_WINDOW + 0x00]
+	stx		%l1, [%g3 + TI_REG_WINDOW + 0x08]
+	stx		%l2, [%g3 + TI_REG_WINDOW + 0x10]
+	stx		%l3, [%g3 + TI_REG_WINDOW + 0x18]
+	stx		%l4, [%g3 + TI_REG_WINDOW + 0x20]
+
+	stx		%l5, [%g3 + TI_REG_WINDOW + 0x28]
+	stx		%l6, [%g3 + TI_REG_WINDOW + 0x30]
+	stx		%l7, [%g3 + TI_REG_WINDOW + 0x38]
+	stx		%i0, [%g3 + TI_REG_WINDOW + 0x40]
+	stx		%i1, [%g3 + TI_REG_WINDOW + 0x48]
+	stx		%i2, [%g3 + TI_REG_WINDOW + 0x50]
+	stx		%i3, [%g3 + TI_REG_WINDOW + 0x58]
+	stx		%i4, [%g3 + TI_REG_WINDOW + 0x60]
+
+	stx		%i5, [%g3 + TI_REG_WINDOW + 0x68]
+	stx		%i6, [%g3 + TI_REG_WINDOW + 0x70]
+	stx		%i7, [%g3 + TI_REG_WINDOW + 0x78]
+	b,pt		%xcc, 2f
+	 add		%g1, 1, %g1
+1:	std		%l0, [%g3 + TI_REG_WINDOW + 0x00]
+	std		%l2, [%g3 + TI_REG_WINDOW + 0x08]
+	std		%l4, [%g3 + TI_REG_WINDOW + 0x10]
+
+	std		%l6, [%g3 + TI_REG_WINDOW + 0x18]
+	std		%i0, [%g3 + TI_REG_WINDOW + 0x20]
+	std		%i2, [%g3 + TI_REG_WINDOW + 0x28]
+	std		%i4, [%g3 + TI_REG_WINDOW + 0x30]
+	std		%i6, [%g3 + TI_REG_WINDOW + 0x38]
+	add		%g1, 1, %g1
+2:	stb		%g1, [%g6 + TI_WSAVED]
+	rdpr		%tstate, %g1
+
+	andcc		%g1, TSTATE_PRIV, %g0
+	saved
+	be,pn		%xcc, window_dax_from_user_common
+	 and		%g1, TSTATE_CWP, %g1
+	retry
+window_dax_from_user_common:
+	wrpr		%g1, %cwp
+	sethi		%hi(109f), %g7
+	ba,pt		%xcc, etrap
+109:	 or		%g7, %lo(109b), %g7
+	mov		%l4, %o1
+	mov		%l5, %o2
+	call		data_access_exception
+	 add		%sp, PTREGS_OFF, %o0
+	ba,pt		%xcc, rtrap
+	 clr		%l6
+	
+
+	.globl		cheetah_plus_patch_winfixup
+cheetah_plus_patch_winfixup:
+	sethi			%hi(cplus_wfinsn_1), %o0
+	sethi			%hi(cplus_winfixup_insn_1), %o2
+	lduw			[%o0 + %lo(cplus_wfinsn_1)], %o1
+	or			%o2, %lo(cplus_winfixup_insn_1), %o2
+	stw			%o1, [%o2]
+	flush			%o2
+
+	sethi			%hi(cplus_wfinsn_2), %o0
+	sethi			%hi(cplus_winfixup_insn_2), %o2
+	lduw			[%o0 + %lo(cplus_wfinsn_2)], %o1
+	or			%o2, %lo(cplus_winfixup_insn_2), %o2
+	stw			%o1, [%o2]
+	flush			%o2
+
+	retl
+	 nop