Bisected: [PATCH v5 8/8] x86/module: enable ROX caches for module text

From: Sergey Senozhatsky
Date: Thu Oct 10 2024 - 04:48:10 EST


On (24/10/09 21:08), Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
>
> Enable execmem's cache of PMD_SIZE'ed pages mapped as ROX for module
> text allocations.
>

With this modprobe disappoints kmemleak

[ 12.700128] kmemleak: Found object by alias at 0xffffffffa000a000
[ 12.702179] CPU: 5 UID: 0 PID: 410 Comm: modprobe Tainted: G N 6.12.0-rc2+ #760
[ 12.704656] Tainted: [N]=TEST
[ 12.705526] Call Trace:
[ 12.706250] <TASK>
[ 12.706888] dump_stack_lvl+0x3e/0xdb
[ 12.707961] __find_and_get_object+0x100/0x110
[ 12.709256] kmemleak_no_scan+0x2e/0xb0
[ 12.710354] kmemleak_load_module+0xad/0xe0
[ 12.711557] load_module+0x2391/0x45a0
[ 12.712507] __se_sys_finit_module+0x4e0/0x7a0
[ 12.713599] do_syscall_64+0x54/0xf0
[ 12.714477] ? irqentry_exit_to_user_mode+0x33/0x100
[ 12.715696] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 12.716931] RIP: 0033:0x7fc7af51f059
[ 12.717816] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8f 1d 0d 00 f7 d8 64 89 01 48
[ 12.722324] RSP: 002b:00007ffc1d0b0c18 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 12.724173] RAX: ffffffffffffffda RBX: 00005618a9439b20 RCX: 00007fc7af51f059
[ 12.725884] RDX: 0000000000000000 RSI: 000056187aea098b RDI: 0000000000000003
[ 12.727617] RBP: 0000000000000000 R08: 0000000000000060 R09: 00005618a943af60
[ 12.729361] R10: 0000000000000038 R11: 0000000000000246 R12: 000056187aea098b
[ 12.731101] R13: 0000000000040000 R14: 00005618a9439ac0 R15: 0000000000000000
[ 12.732814] </TASK>
[ 12.733362] kmemleak: Object 0xffffffffa0000000 (size 2097152):
[ 12.734800] kmemleak: comm "modprobe", pid 410, jiffies 4294880489
[ 12.736334] kmemleak: min_count = 2
[ 12.737228] kmemleak: count = 0
[ 12.738043] kmemleak: flags = 0x5
[ 12.738917] kmemleak: checksum = 0
[ 12.739783] kmemleak: backtrace:
[ 12.740606] kmemleak_vmalloc+0x29/0xc0
[ 12.741532] kasan_alloc_module_shadow+0xbe/0xe0
[ 12.742649] execmem_vmalloc+0x116/0x220
[ 12.743596] execmem_alloc+0xfb/0x3d0
[ 12.744479] load_module+0x1e84/0x45a0
[ 12.745383] __se_sys_finit_module+0x4e0/0x7a0
[ 12.746452] do_syscall_64+0x54/0xf0
[ 12.747319] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 12.748772] kmemleak: Not scanning unknown object at 0xffffffffa000a000
[ 12.750364] CPU: 5 UID: 0 PID: 410 Comm: modprobe Tainted: G N 6.12.0-rc2+ #760
[ 12.752441] Tainted: [N]=TEST
[ 12.753165] Call Trace:
[ 12.753760] <TASK>
[ 12.754279] dump_stack_lvl+0x3e/0xdb
[ 12.755165] kmemleak_load_module+0xad/0xe0
[ 12.756165] load_module+0x2391/0x45a0
[ 12.757068] __se_sys_finit_module+0x4e0/0x7a0
[ 12.758135] do_syscall_64+0x54/0xf0
[ 12.759099] ? irqentry_exit_to_user_mode+0x33/0x100
[ 12.760292] entry_SYSCALL_64_after_hwframe+0x4b/0x53
[ 12.761508] RIP: 0033:0x7fc7af51f059
[ 12.762372] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 8f 1d 0d 00 f7 d8 64 89 01 48
[ 12.772361] RSP: 002b:00007ffc1d0b0c18 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 12.774957] RAX: ffffffffffffffda RBX: 00005618a9439b20 RCX: 00007fc7af51f059
[ 12.776635] RDX: 0000000000000000 RSI: 000056187aea098b RDI: 0000000000000003
[ 12.778283] RBP: 0000000000000000 R08: 0000000000000060 R09: 00005618a943af60
[ 12.779949] R10: 0000000000000038 R11: 0000000000000246 R12: 000056187aea098b
[ 12.781619] R13: 0000000000040000 R14: 00005618a9439ac0 R15: 0000000000000000
[ 12.783319] </TASK>