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> Date: Sun, 25 May 2025 23:20:46 +0200
> From: Jeremie Courreges-Anglas <jca@wxcvbn.org>
>
> On Thu, May 22, 2025 at 08:19:38PM +0200, Mark Kettenis wrote:
> > > Date: Thu, 22 May 2025 18:54:08 +0200
> > > From: Jeremie Courreges-Anglas <jca@wxcvbn.org>
> [...]
> > > *Bzzzt*
> > >
> > > The same LDOM was busy compiling two devel/llvm copies under dpb(1).
> > > Input welcome, I'm not sure yet what other ddb commands could help.
> > >
> > > login: panic: trap type 0x34 (mem address not aligned): pc=1012f68 npc=1012f6c pstate=820006<PRIV,IE>
> > > Stopped at db_enter+0x8: nop
> > > TID PID UID PRFLAGS PFLAGS CPU COMMAND
> > > 57488 1522 0 0x11 0 1 perl
> > > 435923 9891 55 0x1000002 0 4 cc1plus
> > > 135860 36368 55 0x1000002 0 13 cc1plus
> > > 333743 96489 55 0x1000002 0 0 cc1plus
> > > 433162 55422 55 0x1000002 0 9 cc1plus
> > > 171658 49723 55 0x1000002 0 5 cc1plus
> > > 47127 57536 55 0x1000002 0 10 cc1plus
> > > 56600 9350 55 0x1000002 0 14 cc1plus
> > > 159792 13842 55 0x1000002 0 6 cc1plus
> > > 510019 10312 55 0x1000002 0 8 cc1plus
> > > 20489 65709 55 0x1000002 0 15 cc1plus
> > > 337455 42430 55 0x1000002 0 12 cc1plus
> > > 401407 80906 55 0x1000002 0 11 cc1plus
> > > 22993 62317 55 0x1000002 0 2 cc1plus
> > > 114916 17058 55 0x1000002 0 7 cc1plus
> > > *435412 33034 0 0x14000 0x200 3K pagedaemon
> > > trap(400fe6b19b0, 34, 1012f68, 820006, 3, 42) at trap+0x334
> > > Lslowtrap_reenter(40015a58a00, 77b5db2000, deadbeefdeadc0c7, 1d8, 2df0fc468, 468) at Lslowtrap_reenter+0xf8
> > > pmap_page_protect(40010716ab8, c16, 1cc9860, 193dfa0, 1cc9000, 1cc9000) at pmap_page_protect+0x1fc
> > > uvm_pagedeactivate(40010716a50, 40015a50d24, 18667a0, 0, 0, 1c8dac0) at uvm_pagedeactivate+0x54
> > > uvmpd_scan_active(0, 0, 270f2, 18667a0, 0, ffffffffffffffff) at uvmpd_scan_active+0x150
> > > uvm_pageout(400fe6b1e08, 55555556, 18667a0, 1c83f08, 1c83000, 1c8dc18) at uvm_pageout+0x2dc
> > > proc_trampoline(0, 0, 0, 0, 0, 0) at proc_trampoline+0x10
> > > https://www.openbsd.org/ddb.html describes the minimum info required in bug
> > > reports. Insufficient info makes it difficult to find and fix bugs.
> >
> > If there are pmap issues, pmap_page_protect() is certainly the first
> > place I'd look. I'll start looking, but don't expect to have much
> > time until after monday.
>
> Indeed this crash lies in pmap_page_protect(). llvm-objdump -dlS says
> it's stopped at l.2499:
>
> } else {
> pv_entry_t firstpv;
> /* remove mappings */
>
> firstpv = pa_to_pvh(pa);
> mtx_enter(&pg->mdpage.pvmtx);
>
> /* First remove the entire list of continuation pv's*/
> while ((pv = firstpv->pv_next) != NULL) {
> --> data = pseg_get(pv->pv_pmap, pv->pv_va & PV_VAMASK);
>
> /* Save REF/MOD info */
> firstpv->pv_va |= pmap_tte2flags(data);
>
> ; /sys/arch/sparc64/sparc64/pmap.c:2499
> ; data = pseg_get(pv->pv_pmap, pv->pv_va & PV_VAMASK);
> 3c10: a7 29 30 0d sllx %g4, 13, %l3
> 3c14: d2 5c 60 10 ldx [%l1+16], %o1
> 3c18: d0 5c 60 08 ldx [%l1+8], %o0
> --> 3c1c: 40 00 00 00 call 0
> 3c20: 92 0a 40 13 and %o1, %l3, %o1
>
> As discussed with miod I suspect the crash actually lies inside
> pseg_get(), but I can't prove it.
Can you try the diff below. I've nuked pmap_collect() on other
architectures since it is hard to make "mpsafe". The current sparc64
certainly isn't.
If this fixes the crashes, I can see if it is possible to make it
"mpsafe" on sparc64.
Index: arch/sparc64/sparc64/pmap.c
===================================================================
RCS file: /cvs/src/sys/arch/sparc64/sparc64/pmap.c,v
diff -u -p -r1.121 pmap.c
--- arch/sparc64/sparc64/pmap.c 26 Jun 2024 01:40:49 -0000 1.121
+++ arch/sparc64/sparc64/pmap.c 25 May 2025 22:02:13 -0000
@@ -1533,43 +1533,6 @@ pmap_release(struct pmap *pm)
void
pmap_collect(struct pmap *pm)
{
- int i, j, k, n, m, s;
- paddr_t *pdir, *ptbl;
- /* This is a good place to scan the pmaps for page tables with
- * no valid mappings in them and free them. */
-
- /* NEVER GARBAGE COLLECT THE KERNEL PMAP */
- if (pm == pmap_kernel())
- return;
-
- s = splvm();
- for (i=0; i<STSZ; i++) {
- if ((pdir = (paddr_t *)(u_long)ldxa((vaddr_t)&pm->pm_segs[i], ASI_PHYS_CACHED))) {
- m = 0;
- for (k=0; k<PDSZ; k++) {
- if ((ptbl = (paddr_t *)(u_long)ldxa((vaddr_t)&pdir[k], ASI_PHYS_CACHED))) {
- m++;
- n = 0;
- for (j=0; j<PTSZ; j++) {
- int64_t data = ldxa((vaddr_t)&ptbl[j], ASI_PHYS_CACHED);
- if (data&TLB_V)
- n++;
- }
- if (!n) {
- /* Free the damn thing */
- stxa((paddr_t)(u_long)&pdir[k], ASI_PHYS_CACHED, 0);
- pmap_free_page((paddr_t)ptbl, pm);
- }
- }
- }
- if (!m) {
- /* Free the damn thing */
- stxa((paddr_t)(u_long)&pm->pm_segs[i], ASI_PHYS_CACHED, 0);
- pmap_free_page((paddr_t)pdir, pm);
- }
- }
- }
- splx(s);
}
void