Re: 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 via svn-src-head <[email protected]>
| Newsgroups | gmane.os.freebsd.current.scm,gmane.os.freebsd.current,gmane.os.freebsd.devel.hackers,gmane.os.freebsd.devel.ppc |
|---|---|
| Message-ID | <[email protected]> |
[mountd failure example: also at sz_size2index_lookup assert for the same zero'd memory problem.] > On 2020-May-7, at 00:46, Mark Millard <[email protected]> wrote: > > [__je_sz_size2index_tab seems messed up in 2 of the > asserting contexts: first 384 are zero in both. More > before that is also messed up (all zero). I show the > details later below.] > > On 2020-May-6, at 16:57, Mark Millard <marklmi at yahoo.com> wrote: > >> [This explores process crashes that happen during system >> shutdown, in a context not having MALLOC_PRODUCTION= . >> So assert failures are reported as the stopping points.] >> >> It looks like shutdown -p now, shutdown -r now, and the >> like can lead some processes to assert during their exit >> attempt, including a sshd failure (that I've not seen >> before), rpcbind, and nfsd. I show information about the >> observed asserts for those below. >> >> >> sshd hit an assert, failing slab == extent_slab_get(extent) : >> >> (gdb) bt >> #0 thr_kill () at thr_kill.S:4 >> #1 0x50927170 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52 >> #2 0x50886cc0 in abort () at /usr/src/lib/libc/stdlib/abort.c:67 >> #3 0x508834b0 in arena_dalloc (tsdn=<optimized out>, ptr=<optimized out>, tcache=<optimized out>, alloc_ctx=<optimized out>, slow_path=<optimized out>) >> at /usr/src/contrib/jemalloc/include/jemalloc/internal/arena_inlines_b.h:315 >> #4 idalloctm (tsdn=0x500dd040, ptr=0x5008a180, tcache=0x500dd160, alloc_ctx=<optimized out>, is_internal=<optimized out>, slow_path=<optimized out>) >> at /usr/src/contrib/jemalloc/include/jemalloc/internal/jemalloc_internal_inlines_c.h:118 >> #5 0x5087b0a4 in ifree (tsd=0x500dd040, ptr=0x5008a180, tcache=0x500dd160, slow_path=<optimized out>) at jemalloc_jemalloc.c:2590 >> #6 0x5087acac in __je_free_default (ptr=0x5008a180) at jemalloc_jemalloc.c:2784 >> #7 0x5087b294 in __free (ptr=0x5008a180) at jemalloc_jemalloc.c:2852 >> #8 0x10029464 in server_accept_loop (config_s=<optimized out>, sock_in=<optimized out>, sock_out=<optimized out>, newsock=<optimized out>) at /usr/src/crypto/openssh/sshd.c:1185 >> #9 main (ac=<optimized out>, av=0xffffde3c) at /usr/src/crypto/openssh/sshd.c:2009 >> >> . . . >> (gdb) up >> #2 0x50886cc0 in abort () at /usr/src/lib/libc/stdlib/abort.c:67 >> 67 (void)raise(SIGABRT); >> (gdb) up >> #3 0x508834b0 in arena_dalloc (tsdn=<optimized out>, ptr=<optimized out>, tcache=<optimized out>, alloc_ctx=<optimized out>, slow_path=<optimized out>) >> at /usr/src/contrib/jemalloc/include/jemalloc/internal/arena_inlines_b.h:315 >> 315 assert(slab == extent_slab_get(extent)); >> >> (gdb) list >> 310 rtree_ctx = tsd_rtree_ctx(tsdn_tsd(tsdn)); >> 311 extent_t *extent = rtree_extent_read(tsdn, &extents_rtree, >> 312 rtree_ctx, (uintptr_t)ptr, true); >> 313 assert(szind == extent_szind_get(extent)); >> 314 assert(szind < SC_NSIZES); >> 315 assert(slab == extent_slab_get(extent)); >> 316 } >> 317 >> 318 if (likely(slab)) { >> 319 /* Small allocation. */ >> >> More fully: >> >> 285 JEMALLOC_ALWAYS_INLINE void >> 286 arena_dalloc(tsdn_t *tsdn, void *ptr, tcache_t *tcache, >> 287 alloc_ctx_t *alloc_ctx, bool slow_path) { >> 288 assert(!tsdn_null(tsdn) || tcache == NULL); >> 289 assert(ptr != NULL); >> 290 >> 291 if (unlikely(tcache == NULL)) { >> 292 arena_dalloc_no_tcache(tsdn, ptr); >> 293 return; >> 294 } >> 295 >> 296 szind_t szind; >> 297 bool slab; >> 298 rtree_ctx_t *rtree_ctx; >> 299 if (alloc_ctx != NULL) { >> 300 szind = alloc_ctx->szind; >> 301 slab = alloc_ctx->slab; >> 302 assert(szind != SC_NSIZES); >> 303 } else { >> 304 rtree_ctx = tsd_rtree_ctx(tsdn_tsd(tsdn)); >> 305 rtree_szind_slab_read(tsdn, &extents_rtree, rtree_ctx, >> 306 (uintptr_t)ptr, true, &szind, &slab); >> 307 } >> 308 >> 309 if (config_debug) { >> 310 rtree_ctx = tsd_rtree_ctx(tsdn_tsd(tsdn)); >> 311 extent_t *extent = rtree_extent_read(tsdn, &extents_rtree, >> 312 rtree_ctx, (uintptr_t)ptr, true); >> 313 assert(szind == extent_szind_get(extent)); >> 314 assert(szind < SC_NSIZES); >> 315 assert(slab == extent_slab_get(extent)); >> 316 } >> 317 >> 318 if (likely(slab)) { >> 319 /* Small allocation. */ >> 320 tcache_dalloc_small(tsdn_tsd(tsdn), tcache, ptr, szind, >> 321 slow_path); >> 322 } else { >> 323 arena_dalloc_large(tsdn, ptr, tcache, szind, slow_path); >> 324 } >> 325 } > > The following are only shown for contrast with the later > cases of lots of zeros showing up where below shows > non-zero values (taken from sshd.core, which failed > differently): > > (gdb) x/4x __je_arenas+16368/4 > 0x50981ab0 <__je_arenas+16368>: 0x00000000 0x00000000 0x00000000 0x00000009 > (gdb) print/x __je_arenas_lock > $1 = {{{prof_data = {tot_wait_time = {ns = 0x0}, max_wait_time = {ns = 0x0}, n_wait_times = 0x0, n_spin_acquired = 0x0, max_n_thds = 0x0, n_waiting_thds = {repr = 0x0}, n_owner_switches = 0x0, > prev_owner = 0x0, n_lock_ops = 0x0}, lock = 0x5008bf00, postponed_next = 0x50974070, locked = {repr = 0x0}}}, witness = {name = 0x50760b04, rank = 0x3, comp = 0x0, opaque = 0x0, link = { > qre_next = 0x50981b10, qre_prev = 0x50981b10}}, lock_order = 0x0} > (gdb) print/x __je_narenas_auto > $2 = 0x8 > (gdb) print/x malloc_conf > $3 = 0x0 > (gdb) print/x __je_ncpus > $4 = 0x2 > (gdb) print/x __je_manual_arena_base > $5 = 0x9 > (gdb) print/x __je_sz_pind2sz_tab > $6 = {0x1000, 0x2000, 0x3000, 0x4000, 0x5000, 0x6000, 0x7000, 0x8000, 0xa000, 0xc000, 0xe000, 0x10000, 0x14000, 0x18000, 0x1c000, 0x20000, 0x28000, 0x30000, 0x38000, 0x40000, 0x50000, 0x60000, > 0x70000, 0x80000, 0xa0000, 0xc0000, 0xe0000, 0x100000, 0x140000, 0x180000, 0x1c0000, 0x200000, 0x280000, 0x300000, 0x380000, 0x400000, 0x500000, 0x600000, 0x700000, 0x800000, 0xa00000, 0xc00000, > 0xe00000, 0x1000000, 0x1400000, 0x1800000, 0x1c00000, 0x2000000, 0x2800000, 0x3000000, 0x3800000, 0x4000000, 0x5000000, 0x6000000, 0x7000000, 0x8000000, 0xa000000, 0xc000000, 0xe000000, > 0x10000000, 0x14000000, 0x18000000, 0x1c000000, 0x20000000, 0x28000000, 0x30000000, 0x38000000, 0x40000000, 0x50000000, 0x60000000, 0x70000000, 0x70001000} > (gdb) print/x __je_sz_index2size_tab > $7 = {0x8, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80, 0xa0, 0xc0, 0xe0, 0x100, 0x140, 0x180, 0x1c0, 0x200, 0x280, 0x300, 0x380, 0x400, 0x500, 0x600, 0x700, 0x800, 0xa00, 0xc00, 0xe00, 0x1000, > 0x1400, 0x1800, 0x1c00, 0x2000, 0x2800, 0x3000, 0x3800, 0x4000, 0x5000, 0x6000, 0x7000, 0x8000, 0xa000, 0xc000, 0xe000, 0x10000, 0x14000, 0x18000, 0x1c000, 0x20000, 0x28000, 0x30000, 0x38000, > 0x40000, 0x50000, 0x60000, 0x70000, 0x80000, 0xa0000, 0xc0000, 0xe0000, 0x100000, 0x140000, 0x180000, 0x1c0000, 0x200000, 0x280000, 0x300000, 0x380000, 0x400000, 0x500000, 0x600000, 0x700000, > 0x800000, 0xa00000, 0xc00000, 0xe00000, 0x1000000, 0x1400000, 0x1800000, 0x1c00000, 0x2000000, 0x2800000, 0x3000000, 0x3800000, 0x4000000, 0x5000000, 0x6000000, 0x7000000, 0x8000000, 0xa000000, > 0xc000000, 0xe000000, 0x10000000, 0x14000000, 0x18000000, 0x1c000000, 0x20000000, 0x28000000, 0x30000000, 0x38000000, 0x40000000, 0x50000000, 0x60000000, 0x70000000} > (gdb) print/x __je_sz_size2index_tab > $2 = {0x0, 0x0, 0x1, 0x2, 0x2, 0x3, 0x3, 0x4, 0x4, 0x5, 0x5, 0x6, 0x6, 0x7, 0x7, 0x8, 0x8, 0x9, 0x9, 0x9, 0x9, 0xa, 0xa, 0xa, 0xa, 0xb, 0xb, 0xb, 0xb, 0xc, 0xc, 0xc, 0xc, 0xd, 0xd, 0xd, 0xd, 0xd, > 0xd, 0xd, 0xd, 0xe, 0xe, 0xe, 0xe, 0xe, 0xe, 0xe, 0xe, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0xf, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x11 <repeats 16 times>, 0x12 <repeats 16 times>, > 0x13 <repeats 16 times>, 0x14 <repeats 16 times>, 0x15 <repeats 32 times>, 0x16 <repeats 32 times>, 0x17 <repeats 32 times>, 0x18 <repeats 32 times>, 0x19 <repeats 64 times>, > 0x1a <repeats 64 times>, 0x1b <repeats 64 times>, 0x1c <repeats 64 times>} > > >> rpcbind hit an assert, failing ret == sz_size2index_compute(size) : >> >> (gdb) bt >> #0 thr_kill () at thr_kill.S:4 >> #1 0x502f2170 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52 >> #2 0x50251d04 in abort () at /usr/src/lib/libc/stdlib/abort.c:79 >> #3 0x5024f260 in sz_size2index_lookup (size=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:159 >> #4 sz_size2index (size=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:166 >> #5 imalloc_body (sopts=0xffffb360, dopts=0xffffb340, tsd=0x5009a018) at jemalloc_jemalloc.c:2066 >> #6 0x50244874 in imalloc (sopts=0xffffb360, dopts=0xffffb340) at /usr/src/contrib/jemalloc/include/jemalloc/internal/tsd.h:331 >> #7 0x50244fe8 in __calloc (num=1, size=96) at jemalloc_jemalloc.c:2498 >> #8 0x50265690 in svc_xprt_alloc () at /usr/src/lib/libc/rpc/svc.c:541 >> #9 0x502635f4 in makefd_xprt (fd=14, sendsize=9000, recvsize=9000) at /usr/src/lib/libc/rpc/svc_vc.c:250 >> #10 0x502644b4 in rendezvous_request (xprt=0x5004c000, msg=<optimized out>) at /usr/src/lib/libc/rpc/svc_vc.c:315 >> #11 0x50265a98 in svc_getreq_common (fd=<optimized out>) at /usr/src/lib/libc/rpc/svc.c:640 >> #12 0x50265d1c in svc_getreq_poll (pfdp=<optimized out>, pollretval=1) at /usr/src/lib/libc/rpc/svc.c:739 >> #13 0x10018568 in my_svc_run () at /usr/src/usr.sbin/rpcbind/rpcb_svc_com.c:1167 >> #14 0x10014ad8 in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/usr.sbin/rpcbind/rpcbind.c:250 >> (gdb) up 3 >> #3 0x5024f260 in sz_size2index_lookup (size=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:159 >> 159 assert(ret == sz_size2index_compute(size)); >> (gdb) print ret >> $1 = 0 >> >> 154 JEMALLOC_ALWAYS_INLINE szind_t >> 155 sz_size2index_lookup(size_t size) { >> 156 assert(size <= SC_LOOKUP_MAXCLASS); >> 157 szind_t ret = (sz_size2index_tab[(size + (ZU(1) << SC_LG_TINY_MIN) - 1) >> 158 >> SC_LG_TINY_MIN]); >> 159 assert(ret == sz_size2index_compute(size)); >> 160 return ret; >> 161 } > > gdb reports for sz_size2index_tab (really JEMALLOC_N(sz_size2index_tab), > i.e., __je_sz_size2index_tab): > > (gdb) print/x __je_sz_size2index_tab > $1 = {0x0 <repeats 384 times>, 0x1a, 0x1b <repeats 64 times>, 0x1c <repeats 64 times>} > > Also: > > (gdb) x/4x __je_arenas+16368/4 > 0x5034cab0 <__je_arenas+16368>: 0x00000000 0x00000000 0x00000000 0x00000000 > (gdb) print/x __je_arenas_lock > $8 = {{{prof_data = {tot_wait_time = {ns = 0x0}, max_wait_time = {ns = 0x0}, n_wait_times = 0x0, n_spin_acquired = 0x0, max_n_thds = 0x0, n_waiting_thds = {repr = 0x0}, n_owner_switches = 0x0, > prev_owner = 0x0, n_lock_ops = 0x0}, lock = 0x0, postponed_next = 0x0, locked = {repr = 0x0}}}, witness = {name = 0x0, rank = 0x0, comp = 0x0, opaque = 0x0, link = {qre_next = 0x0, > qre_prev = 0x0}}, lock_order = 0x0} > (gdb) print/x __je_narenas_auto > $9 = 0x0 > (gdb) print/x malloc_conf > $10 = 0x0 > (gdb) print/x __je_ncpus > $11 = 0x0 > (gdb) print/x __je_manual_arena_base > $12 = 0x0 > (gdb) print/x __je_sz_pind2sz_tab > $13 = {0x0 <repeats 72 times>} > (gdb) print/x __je_sz_index2size_tab > $14 = {0x0 <repeats 104 times>} > > >> nfsd hit an assert, failing ret == sz_size2index_compute(size) > > [Correction: That should have referenced sz_index2size_lookup(index).] > >> (also, but a different caller of sz_size2index): > > [Correction: The "also" comment should be ignored: > sz_index2size_lookup(index) is referenced below.] > >> >> (gdb) bt >> #0 thr_kill () at thr_kill.S:4 >> #1 0x502b2170 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52 >> #2 0x50211cc0 in abort () at /usr/src/lib/libc/stdlib/abort.c:67 >> #3 0x50206104 in sz_index2size_lookup (index=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:200 >> #4 sz_index2size (index=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:207 >> #5 ifree (tsd=0x50094018, ptr=0x50041028, tcache=0x50094138, slow_path=<optimized out>) at jemalloc_jemalloc.c:2583 >> #6 0x50205cac in __je_free_default (ptr=0x50041028) at jemalloc_jemalloc.c:2784 >> #7 0x50206294 in __free (ptr=0x50041028) at jemalloc_jemalloc.c:2852 >> #8 0x50287ec8 in ns_src_free (src=0x50329004, srclistsize=<optimized out>) at /usr/src/lib/libc/net/nsdispatch.c:452 >> #9 ns_dbt_free (dbt=0x50329000) at /usr/src/lib/libc/net/nsdispatch.c:436 >> #10 vector_free (vec=0x50329000, count=<optimized out>, esize=12, free_elem=<optimized out>) at /usr/src/lib/libc/net/nsdispatch.c:253 >> #11 nss_atexit () at /usr/src/lib/libc/net/nsdispatch.c:578 >> #12 0x5028d958 in __cxa_finalize (dso=0x0) at /usr/src/lib/libc/stdlib/atexit.c:240 >> #13 0x502117f8 in exit (status=0) at /usr/src/lib/libc/stdlib/exit.c:74 >> #14 0x10013f9c in child_cleanup (signo=<optimized out>) at /usr/src/usr.sbin/nfsd/nfsd.c:969 >> #15 <signal handler called> >> #16 0x00000000 in ?? () >> >> (gdb) up 3 >> #3 0x50206104 in sz_index2size_lookup (index=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:200 >> 200 assert(ret == sz_index2size_compute(index)); >> >> (ret is optimized out.) >> >> 197 JEMALLOC_ALWAYS_INLINE size_t >> 198 sz_index2size_lookup(szind_t index) { >> 199 size_t ret = (size_t)sz_index2size_tab[index]; >> 200 assert(ret == sz_index2size_compute(index)); >> 201 return ret; >> 202 } > > (gdb) print/x __je_sz_index2size_tab > $3 = {0x0 <repeats 104 times>} > > Also: > > (gdb) x/4x __je_arenas+16368/4 > 0x5030cab0 <__je_arenas+16368>: 0x00000000 0x00000000 0x00000000 0x00000000 > (gdb) print/x __je_arenas_lock > $8 = {{{prof_data = {tot_wait_time = {ns = 0x0}, max_wait_time = {ns = 0x0}, n_wait_times = 0x0, n_spin_acquired = 0x0, max_n_thds = 0x0, n_waiting_thds = {repr = 0x0}, n_owner_switches = 0x0, > prev_owner = 0x0, n_lock_ops = 0x0}, lock = 0x0, postponed_next = 0x0, locked = {repr = 0x0}}}, witness = {name = 0x0, rank = 0x0, comp = 0x0, opaque = 0x0, link = {qre_next = 0x0, > qre_prev = 0x0}}, lock_order = 0x0} > (gdb) print/x __je_narenas_auto > $9 = 0x0 > (gdb) print/x malloc_conf > $10 = 0x0 > (gdb) print/x __je_ncpus > $11 = 0x0 > (gdb) print/x __je_manual_arena_base > $12 = 0x0 > (gdb) print/x __je_sz_pind2sz_tab > $13 = {0x0 <repeats 72 times>} > (gdb) print/x __je_sz_size2index_tab > $1 = {0x0 <repeats 384 times>, 0x1a, 0x1b <repeats 64 times>, 0x1c <repeats 64 times>} > >> Booting and immediately trying something like: >> >> service nfsd stop >> >> did not lead to a failure. But may be after >> a while it would and be less drastic than a >> reboot or power down. > > More detail: > > So, for rpcbind and nfds at some point a large part of > __je_sz_size2index_tab is being stomped on, as is all of > __je_sz_index2size_tab and more. > > For rpcbind, the following area is zero but in a > live process is not all-zero (I show the partially > non-zero live-process context instead of the all-zero > .core file content): > > 0x5034cab0 <__je_arenas+16368>: 0x00000000 0x00000000 0x00000000 0x00000009 > 0x5034cac0 <__je_arenas_lock>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5034cad0 <__je_arenas_lock+16>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5034cae0 <__je_arenas_lock+32>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5034caf0 <__je_arenas_lock+48>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5034cb00 <__je_arenas_lock+64>: 0x00000000 0x5033f070 0x00000000 0x00000000 > 0x5034cb10 <__je_arenas_lock+80>: 0x5012bb04 0x00000003 0x00000000 0x00000000 > 0x5034cb20 <__je_arenas_lock+96>: 0x5034cb10 0x5034cb10 0x00000000 0x00000000 > > Then the memory in the crash continues to be zero until: > > 0x5034d000 <__je_sz_size2index_tab+384>: 0x1a1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b > > Notice the interesting page boundary for where non-zero > is first available again! > > Between __je_arenas_lock and __je_sz_size2index_tab are: > > 0x5034cb30 __je_narenas_auto > 0x5034cb38 malloc_conf > 0x5034cb3c __je_ncpus > 0x5034cb40 __je_manual_arena_base > 0x5034cb80 __je_sz_pind2sz_tab > 0x5034ccc0 __je_sz_index2size_tab > 0x5034ce80 __je_sz_size2index_tab > > For nfsd, it is similar (again showing the partially > non-zero live process context instead of the all-zeros > from the .core file): > > 0x5030cab0 <__je_arenas+16368>: 0x00000000 0x00000000 0x00000000 0x00000009 > 0x5030cac0 <__je_arenas_lock>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5030cad0 <__je_arenas_lock+16>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5030cae0 <__je_arenas_lock+32>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5030caf0 <__je_arenas_lock+48>: 0x00000000 0x00000000 0x00000000 0x00000000 > 0x5030cb00 <__je_arenas_lock+64>: 0x00000000 0x502ff070 0x00000000 0x00000000 > 0x5030cb10 <__je_arenas_lock+80>: 0x500ebb04 0x00000003 0x00000000 0x00000000 > 0x5030cb20 <__je_arenas_lock+96>: 0x5030cb10 0x5030cb10 0x00000000 0x00000000 > > Then the memory in the crash continues to be zero until: > > 0x5030d000 <__je_sz_size2index_tab+384>: 0x1a1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b > > Notice the interesting page boundary for where non-zero > is first available again! > > Between __je_arenas_lock and __je_sz_size2index_tab are: > > 0x5030cb30 __je_narenas_auto > 0x5030cb38 malloc_conf > 0x5030cb3c __je_ncpus > 0x5030cb40 __je_manual_arena_base > 0x5030cb80 __je_sz_pind2sz_tab > 0x5030ccc0 __je_sz_index2size_tab > 0x5030ce80 __je_sz_size2index_tab > > > Note: because __je_arenas is normally > mostly zero for these contexts, I can > not tell where the memory trashing > started, only where it replaced non-zero > values with zeros. > I got a mountd assert failure in sz_size2index_lookup while attempting __calloc during makefd_xprt. (gdb) bt #0 thr_kill () at thr_kill.S:4 #1 0x50301170 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52 #2 0x50260cc0 in abort () at /usr/src/lib/libc/stdlib/abort.c:67 #3 0x5025e260 in sz_size2index_lookup (size=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:159 #4 sz_size2index (size=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:166 #5 imalloc_body (sopts=0xffffd000, dopts=0xffffcfe0, tsd=0x50094018) at jemalloc_jemalloc.c:2066 #6 0x50253874 in imalloc (sopts=0xffffd000, dopts=0xffffcfe0) at /usr/src/contrib/jemalloc/include/jemalloc/internal/tsd.h:331 #7 0x50253fe8 in __calloc (num=1, size=96) at jemalloc_jemalloc.c:2498 #8 0x50274690 in svc_xprt_alloc () at /usr/src/lib/libc/rpc/svc.c:541 #9 0x502725f4 in makefd_xprt (fd=10, sendsize=9000, recvsize=9000) at /usr/src/lib/libc/rpc/svc_vc.c:250 #10 0x502734b4 in rendezvous_request (xprt=0x5007b120, msg=<optimized out>) at /usr/src/lib/libc/rpc/svc_vc.c:315 #11 0x50274a98 in svc_getreq_common (fd=<optimized out>) at /usr/src/lib/libc/rpc/svc.c:640 #12 0x502748e0 in svc_getreqset (readfds=<optimized out>) at /usr/src/lib/libc/rpc/svc.c:611 #13 0x1001434c in main (argc=<optimized out>, argv=0xffffde3c) at /usr/src/usr.sbin/mountd/mountd.c:683 (gdb) up 3 #3 0x5025e260 in sz_size2index_lookup (size=<optimized out>) at /usr/src/contrib/jemalloc/include/jemalloc/internal/sz.h:159 159 assert(ret == sz_size2index_compute(size)); Again there is that area of memory that has been zeroed, with the same stopping point in __je_sz_size2index_tab: (gdb) print/x __je_narenas_auto $2 = 0x0 (gdb) print/x malloc_conf $3 = 0x0 (gdb) print/x __je_ncpus $4 = 0x0 (gdb) print/x __je_manual_arena_base $5 = 0x0 (gdb) print/x __je_sz_pind2sz_tab $6 = {0x0 <repeats 72 times>} (gdb) print/x __je_sz_size2index_tab $7 = {0x0 <repeats 384 times>, 0x1a, 0x1b <repeats 64 times>, 0x1c <repeats 64 times>} Showing where the zeroing stopped: . . . (gdb) x/156x __je_sz_size2index_tab 0x5035be80 <__je_sz_size2index_tab>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035be90 <__je_sz_size2index_tab+16>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bea0 <__je_sz_size2index_tab+32>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035beb0 <__je_sz_size2index_tab+48>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bec0 <__je_sz_size2index_tab+64>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bed0 <__je_sz_size2index_tab+80>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bee0 <__je_sz_size2index_tab+96>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bef0 <__je_sz_size2index_tab+112>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf00 <__je_sz_size2index_tab+128>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf10 <__je_sz_size2index_tab+144>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf20 <__je_sz_size2index_tab+160>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf30 <__je_sz_size2index_tab+176>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf40 <__je_sz_size2index_tab+192>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf50 <__je_sz_size2index_tab+208>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf60 <__je_sz_size2index_tab+224>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf70 <__je_sz_size2index_tab+240>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf80 <__je_sz_size2index_tab+256>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bf90 <__je_sz_size2index_tab+272>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bfa0 <__je_sz_size2index_tab+288>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bfb0 <__je_sz_size2index_tab+304>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bfc0 <__je_sz_size2index_tab+320>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bfd0 <__je_sz_size2index_tab+336>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bfe0 <__je_sz_size2index_tab+352>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035bff0 <__je_sz_size2index_tab+368>: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035c000 <__je_sz_size2index_tab+384>: 0x1a1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x5035c010 <__je_sz_size2index_tab+400>: 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x5035c020 <__je_sz_size2index_tab+416>: 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x5035c030 <__je_sz_size2index_tab+432>: 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x1b1b1b1b 0x5035c040 <__je_sz_size2index_tab+448>: 0x1b1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x5035c050 <__je_sz_size2index_tab+464>: 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x5035c060 <__je_sz_size2index_tab+480>: 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x5035c070 <__je_sz_size2index_tab+496>: 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x1c1c1c1c 0x5035c080 <__je_sz_size2index_tab+512>: 0x1c000000 0x00000000 0x50303474 0x00000000 0x5035c090: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035c0a0: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035c0b0: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035c0c0: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035c0d0: 0x00000000 0x00000000 0x00000000 0x00000000 0x5035c0e0: 0x00000000 0x00000000 0x00000000 0x00000000 Again: a nice page boundary: 0x5035c000 for where the zeros stop. Note that, despite the address ranges shifting around between programs, the same global variables are being stomped on, stopping at the same index into __je_sz_size2index_tab in each of the 3 programs. It always is page aligned there in my context. (The sshd example is different. I've yet to explore it much.) === Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)