On Wed, Jun 26, 2024 at 7:45 PM Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> wrote: > > On 6/26/24 3:40 AM, Mateusz Guzik wrote: > > On Tue, Jun 04, 2024 at 10:41:40AM -0700, Sidhartha Kumar wrote: > >> Use mas->store_type to simplify the logic of identifying the type of > >> write. > >> > >> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> > >> --- > >> lib/maple_tree.c | 6 ++---- > >> 1 file changed, 2 insertions(+), 4 deletions(-) > >> > >> diff --git a/lib/maple_tree.c b/lib/maple_tree.c > >> index 314691fd1c67..faadddbe2086 100644 > >> --- a/lib/maple_tree.c > >> +++ b/lib/maple_tree.c > >> @@ -3437,12 +3437,10 @@ static noinline_for_kasan int mas_commit_b_node(struct ma_wr_state *wr_mas, > >> enum maple_type b_type = b_node->type; > >> > >> old_enode = wr_mas->mas->node; > >> - if ((b_end < mt_min_slots[b_type]) && > >> - (!mte_is_root(old_enode)) && > >> - (mas_mt_height(wr_mas->mas) > 1)) > >> + if (wr_mas->mas->store_type == wr_rebalance) > >> return mas_rebalance(wr_mas->mas, b_node); > >> > >> - if (b_end >= mt_slots[b_type]) > >> + if (wr_mas->mas->store_type == wr_split_store) > >> return mas_split(wr_mas->mas, b_node); > >> > >> if (mas_reuse_node(wr_mas, b_node, end)) > > > > > > This reliably results in "kernel BUG at mm/mmap.c:3412!". > > > > bt below > > > > reliably reproduces as follows: spawn "perf top", hit enter twice to > > disassemble a func. tui hangs indefinitely, console shows the splat > > below. > > > > Hello, > > Thanks for your report. When I run perf top and disassemble a function tui > doesn't hang. In dmesg I see: > > [ 17.836399] perf: interrupt took too long (2705 > 2500), lowering > kernel.perf_event_max_sample_rate to 73000 > [ 17.837532] perf: interrupt took too long (3561 > 3381), lowering > kernel.perf_event_max_sample_rate to 56000 > [ 17.838818] perf: interrupt took too long (4654 > 4451), lowering > kernel.perf_event_max_sample_rate to 42000 > [ 17.840267] perf: interrupt took too long (5930 > 5817), lowering > kernel.perf_event_max_sample_rate to 33000 > > > but not the bug that your seeing. Could you send your config file so I could > test with that? > https://people.freebsd.org/~mjg/.linux-crap/.config-maple-crash I verified again this reliably crashes when going to: commit 30e5748b1d44e3eefc41773e27c63e51910ed718 (HEAD) Author: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx> Date: Tue Jun 18 13:47:45 2024 -0700 maple_tree: simplify mas_commit_b_node() on linux-next Userspace is Debian 12 (which may be of significance), but just in case I'll note I'm building the kernel on a Ubuntu 24.04. > Thanks, > Sid > > > > > I verified going one commit down produces a working kernel. > > > > kernel BUG at mm/mmap.c:3412! > > [ 35.820042] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > > [ 35.821101] CPU: 4 PID: 1066 Comm: perf-top-UI Tainted: G W 6.10.0-rc5-00304-g30e5748b1d44 #155 > > [ 35.822929] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014 > > [ 35.824957] RIP: 0010:exit_mmap+0x392/0x3a0 > > [ 35.825794] Code: ef e8 02 9f fe ff eb d7 be 01 00 00 00 48 89 ef e8 73 a3 fe ff eb be 31 f6 48 89 ef > > e8 a7 a2 fe ff eb a8 0f 0b e9 75 fe ff ff <0f> 0b e8 a7 b2 c1 00 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 > > [ 35.829141] RSP: 0018:ff7fe6c8c2393c40 EFLAGS: 00010293 > > [ 35.830103] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > > [ 35.831398] RDX: ff39fe34499c3c00 RSI: 0000000000000001 RDI: ff39fe34499c3c08 > > [ 35.832705] RBP: ff39fe3441a28580 R08: 000000000000000c R09: 0000000000000060 > > [ 35.834010] R10: ff39fe3450ad5600 R11: 0000000000000000 R12: 00000000000000e8 > > [ 35.835295] R13: 0000000000003593 R14: ff39fe3441a28628 R15: ff39fe3441a285c0 > > [ 35.836569] FS: 0000000000000000(0000) GS:ff39fe39a7700000(0000) knlGS:0000000000000000 > > [ 35.838042] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 35.839093] CR2: 00007efd624f39ed CR3: 000000010130e001 CR4: 0000000000371ef0 > > [ 35.840389] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [ 35.841892] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 > > [ 35.843182] Call Trace: > > [ 35.843646] <TASK> > > [ 35.844051] ? die+0x36/0x90 > > [ 35.844602] ? do_trap+0xdd/0x100 > > [ 35.845226] ? exit_mmap+0x392/0x3a0 > > [ 35.845915] ? do_error_trap+0x65/0x80 > > [ 35.846614] ? exit_mmap+0x392/0x3a0 > > [ 35.847287] ? exc_invalid_op+0x50/0x70 > > [ 35.847999] ? exit_mmap+0x392/0x3a0 > > [ 35.848662] ? asm_exc_invalid_op+0x1a/0x20 > > [ 35.849437] ? exit_mmap+0x392/0x3a0 > > [ 35.850120] __mmput+0x3d/0x130 > > [ 35.850713] begin_new_exec+0x4ed/0xb00 > > [ 35.851428] ? load_elf_phdrs+0x6c/0xc0 > > [ 35.852150] load_elf_binary+0x2ca/0x15a0 > > [ 35.852890] ? __kernel_read+0x1d8/0x2f0 > > [ 35.853621] ? __kernel_read+0x1d8/0x2f0 > > [ 35.854348] ? load_misc_binary+0x1f6/0x310 > > [ 35.855113] bprm_execve+0x243/0x600 > > [ 35.855784] do_execveat_common.isra.0+0x1bd/0x220 > > [ 35.856672] __x64_sys_execve+0x36/0x40 > > [ 35.857384] do_syscall_64+0x52/0x150 > > [ 35.858088] entry_SYSCALL_64_after_hwframe+0x76/0x7e > > [ 35.859014] RIP: 0033:0x7efd624f3a17 > > [ 35.859677] Code: Unable to access opcode bytes at 0x7efd624f39ed. > > [ 35.860790] RSP: 002b:00007efd48bf8dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000003b > > [ 35.862170] RAX: ffffffffffffffda RBX: 000055e5736a44e3 RCX: 00007efd624f3a17 > > [ 35.863472] RDX: 000055e59c315000 RSI: 00007efd48bf9050 RDI: 000055e5736a44e3 > > [ 35.864768] RBP: 00007efd48bf8e40 R08: 0000000000000000 R09: 00007efd48c006c0 > > [ 35.866475] R10: 00007efd62430e50 R11: 0000000000000202 R12: 00007efd48bf9050 > > [ 35.868167] R13: 000055e59c315000 R14: 0000000000000001 R15: 0000000000000001 > > [ 35.869873] </TASK> > > [ 35.870676] Modules linked in: > > [ 35.871944] ---[ end trace 0000000000000000 ]--- > > > -- Mateusz Guzik <mjguzik gmail.com>
