svn commit: r360233 - in head: contrib/jemalloc . . . : This partially breaks a 2-socket 32-bit powerpc (old PowerMac G4) based on head -r360311

[Mark Millard]

On 2020-Jun-16, at 19:32, Justin Hibbits <chmeeedalf at gmail.com> wrote:

> (Removing hackers and current, too many cross-lists already, and those
> interested in reading this are probably already on ppc@)
> 
> Mark,
> 
> Can you try this updated patch?  Again, I've only compiled it, I
> haven't tested it, so it may also explode.  However, it more closely
> mimics exactly what moea64 does.

Sure . . . But no luck.

Same crash, same backtrace related information,
other than the "in page" figure and the "time"
figure:

panic: vm_page_free_prep: mapping flags set in page 0xd0300fc0
cpuid = 0
time = 1592362496
KDB: stack backtrace:
0xd2dc4340: at kdb_backtrace+0x64
0xd2dc43a0: at vpanic+0x208
0xd2dc4410: at panic+0x64
0xd2dc4450: at vm_page_free_prep+0x348
0xd2dc4470: at vm_page_free_toq+0x3c
0xd2dc4490: at vm_page_free+0x20
0xd2dc44a0: at vm_object_collapse+0x4ac
0xd2dc4510: at vm_object_deallocate+0x430
0xd2dc4550: at vm_map_process_deferred+0xec
0xd2dc4570: at vm_map_remove+0x12c
0xd2dc4590: at exec_new_vmspace+0x20c
0xd2dc45f0: at exec_elf32_imgact+0xa70
0xd2dc46a0: at kern_execve+0x600
0xd2dc4910: at sys_execve+0x84
0xd2dc4970: at trap+0x748
0xd2dc4a10: at powerpc_interrupt+0x178
0xd2dc4a40: user SC trap by 0x100d71f8: srr1=0xf032
            r1=0xffffd810 cr=0x82000280 xer=0 ctr=0x10173810 frame=0xd2dc4a48
KDB: enter: panic

/wrkdirs/usr/ports/devel/gdb/work-py37/gdb-9.1/gdb/inferior.c:283: internal-error: struct inferior *find_inferior_pid(int): Assertion `pid != 0' failed.


FYI . . .

(m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0
is failing when (m->oflags & VPO_UNMANAGED) == 0 holds in
vm_page_free_prep. See the last KASSERT in the code
quoted below. Does this suggest the lack of someplace
not clearing some flags in m->a.flags that should be
doing so?

static bool
vm_page_free_prep(vm_page_t m)
{
 
        /*
         * Synchronize with threads that have dropped a reference to this
         * page.
         */
        atomic_thread_fence_acq();
 
#if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP)
        if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) {
                uint64_t *p;
                int i;
                p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
                for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++)
                        KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx",
                            m, i, (uintmax_t)*p));
        }
#endif
        if ((m->oflags & VPO_UNMANAGED) == 0) {
                KASSERT(!pmap_page_is_mapped(m),
                    ("vm_page_free_prep: freeing mapped page %p", m));
                KASSERT((m->a.flags & (PGA_EXECUTABLE | PGA_WRITEABLE)) == 0,
                    ("vm_page_free_prep: mapping flags set in page %p", m));
        } else {
. . .



===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)