diff options
| -rw-r--r-- | sys/arch/sparc64/sparc64/locore.s | 71 |
1 files changed, 69 insertions, 2 deletions
diff --git a/sys/arch/sparc64/sparc64/locore.s b/sys/arch/sparc64/sparc64/locore.s index 49c659ea9e2..7c7a58a383f 100644 --- a/sys/arch/sparc64/sparc64/locore.s +++ b/sys/arch/sparc64/sparc64/locore.s @@ -1,4 +1,4 @@ -/* $OpenBSD: locore.s,v 1.52 2005/08/08 19:48:37 kettenis Exp $ */ +/* $OpenBSD: locore.s,v 1.53 2006/01/03 20:57:36 kettenis Exp $ */ /* $NetBSD: locore.s,v 1.137 2001/08/13 06:10:10 jdolecek Exp $ */ /* @@ -918,7 +918,7 @@ kdatafault: UTRAP 0x031 ! 031 = data MMU miss -- no MMU VTRAP T_DATA_ERROR, winfault ! 032 = data fetch fault VTRAP T_DATA_PROT, winfault ! 033 = data fetch fault - TRAP T_ALIGN ! 034 = address alignment error -- we could fix it inline... + VTRAP T_ALIGN, checkalign ! 034 = address alignment error -- we could fix it inline... ! sir; nop; TA8 ! DEBUG -- trap all kernel alignment errors TRAP T_LDDF_ALIGN ! 035 = LDDF address alignment error -- we could fix it inline... TRAP T_STDF_ALIGN ! 036 = STDF address alignment error -- we could fix it inline... @@ -2609,6 +2609,73 @@ fp_exception: NOTREACHED /* + * We're here because we took an alignment fault in NUCLEUS context. + * This could be a kernel bug or it could be due to saving or restoring + * a user window to/from an invalid stack pointer. + * + * If the latter is the case, we could try to emulate unaligned accesses, + * but we really don't know where to store the registers since we can't + * determine if there's a stack bias. Or we could store all the regs + * into the PCB and punt, until the user program uses up all the CPU's + * register windows and we run out of places to store them. So for + * simplicity we'll just blow them away and enter the trap code which + * will generate a bus error. Debugging the problem will be a bit + * complicated since lots of register windows will be lost, but what + * can we do? + * + * XXX The trap code generates SIGKILL for now. + */ +checkalign: + rdpr %tl, %g2 + subcc %g2, 1, %g1 + bneg,pn %icc, slowtrap ! Huh? + sethi %hi(CPCB), %g6 ! Get current pcb + + wrpr %g1, 0, %tl + rdpr %tt, %g7 + rdpr %tstate, %g4 + andn %g7, 0x07f, %g5 ! Window spill traps are all 0b 0000 10xx xxxx + cmp %g5, 0x080 ! Window fill traps are all 0b 0000 11xx xxxx + bne,a,pn %icc, slowtrap + nop + + /* + * %g1 -- current tl + * %g2 -- original tl + * %g4 -- tstate + * %g7 -- tt + */ + + and %g4, CWP, %g5 + wrpr %g5, %cwp ! Go back to the original register window + + rdpr %otherwin, %g6 + rdpr %cansave, %g5 + add %g5, %g6, %g5 + wrpr %g0, 0, %otherwin ! Just blow away all user windows + wrpr %g5, 0, %cansave + rdpr %canrestore, %g5 + wrpr %g5, 0, %cleanwin + + wrpr %g0, T_ALIGN, %tt ! This was an alignment fault + /* + * Now we need to determine if this was a userland store/load or not. + * Userland stores occur in anything other than the kernel spill/fill + * handlers (trap type 0x9x/0xdx). + */ + and %g7, 0xff0, %g5 + cmp %g5, 0x90 + bz,pn %icc, slowtrap + nop + cmp %g5, 0xd0 + bz,pn %icc, slowtrap + nop + and %g7, 0xfc0, %g5 + wrpr %g5, 0, %tt + ba,a,pt %icc, slowtrap + nop + +/* * slowtrap() builds a trap frame and calls trap(). * This is called `slowtrap' because it *is*.... * We have to build a full frame for ptrace(), for instance. |