| /* $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: |
| sethi %hi(sparc64_kern_pri_context), %l1 |
| ldx [%l1 + %lo(sparc64_kern_pri_context)], %l1 |
| mov PRIMARY_CONTEXT, %g1 |
| stxa %l1, [%g1] ASI_DMMU |
| sethi %hi(KERNBASE), %l1 |
| flush %l1 |
| retl |
| nop |
| |
| .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: |
| TRAP_LOAD_THREAD_REG(%g6, %g1) |
| 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 |
| LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3) |
| |
| /* 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: |
| TRAP_LOAD_THREAD_REG(%g6, %g1) |
| 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,a,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: |
| TRAP_LOAD_THREAD_REG(%g6, %g1) |
| 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. |
| LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3) |
| call mem_address_unaligned |
| add %sp, PTREGS_OFF, %o0 |
| |
| b,pt %xcc, rtrap |
| nop ! yes, the nop is correct |
| spill_fixup_mna: |
| TRAP_LOAD_THREAD_REG(%g6, %g1) |
| 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 |
| |
| .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: |
| TRAP_LOAD_THREAD_REG(%g6, %g1) |
| 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 spitfire_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. |
| LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3) |
| call spitfire_data_access_exception |
| add %sp, PTREGS_OFF, %o0 |
| |
| b,pt %xcc, rtrap |
| nop ! yes, the nop is correct |
| spill_fixup_dax: |
| TRAP_LOAD_THREAD_REG(%g6, %g1) |
| 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 spitfire_data_access_exception |
| add %sp, PTREGS_OFF, %o0 |
| ba,pt %xcc, rtrap |
| clr %l6 |
