Josh Poimboeuf a683f7da21 kmod/core: fix crash with !CONFIG_DEBUG_SET_MODULE_RONX ... When loading a patch module on a kernel with !CONFIG_DEBUG_SET_MODULE_RONX, the following crash occurs: loading core module: /root/src/kpatch/kpatch/../kmod/core/kpatch.ko loading patch module: kpatch-meminfo-string.ko BUG: unable to handle kernel paging request at ffffffffa0010cc0 IP: [<ffffffff8125ecb0>] do_init_module+0x84/0x1af PGD 13d3067 PUD 13d4063 PMD 1e1ee067 PTE 1e1a0161 Oops: 0003 [#1] Modules linked in: kpatch_meminfo_string(O+) kpatch(O) CPU: 0 PID: 149 Comm: insmod Tainted: G O K 4.1.0+ #1 task: ffff88001e17b810 ti: ffff88001e1cc000 task.ti: ffff88001e1cc000 RIP: 0010:[<ffffffff8125ecb0>] [<ffffffff8125ecb0>] do_init_module+0x84/0x1af RSP: 0018:ffff88001e1cfda8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffffffa0010cc0 RCX: 0000000080a02001 RDX: 0000000000000024 RSI: 0000000000000000 RDI: ffffffff813fabe0 RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000d0000000 R10: ffffffffa000e000 R11: 0000000000000001 R12: ffff88001eb58638 R13: ffffffffa0010d10 R14: 0000000000000001 R15: 0000000000000000 FS: 00007f0ae00aa700(0000) GS:ffffffff813e1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffffffffa0010cc0 CR3: 000000001e181000 CR4: 00000000000006b0 Stack: ffff88001e1cfed8 0000000000000001 ffffffffa0010cc0 ffffffff81058aac ffff88001e207680 00000000810a462f ffffc90000096890 0000000000000e00 ffffffff00000016 ffffffff8126cd40 ffff88001eaa6a08 ffff88001e1cfe48 Call Trace: [<ffffffff81058aac>] ? load_module+0x18ad/0x18e9 [<ffffffff81056290>] ? copy_module_from_fd+0x86/0xdf [<ffffffff81058c1e>] ? SyS_finit_module+0x56/0x61 [<ffffffff81261854>] ? system_call_fastpath+0x12/0x6a Code: f8 00 00 00 74 23 49 c7 c0 80 ca 26 81 48 8d 53 18 89 c1 4c 89 c6 48 c7 c7 6d ef 36 81 31 c0 e8 16 fb ff ff e8 18 06 00 00 31 f6 <c7> 03 00 00 00 00 48 89 da 48 c7 c7 c0 c9 3f 81 e8 7e b3 dd ff RIP [<ffffffff8125ecb0>] do_init_module+0x84/0x1af RSP <ffff88001e1cfda8> CR2: ffffffffa0010cc0 With !CONFIG_DEBUG_SET_MODULE_RONX, module text and rodata pages are writable, and the debug_align() macro allows the module struct to share a page with executable text. When klp_write_module_reloc() calls set_memory_ro() on the page, it effectively turns the module struct into a read-only structure, resulting in a page fault when load_module() does "mod->state = MODULE_STATE_LIVE". Fixes: #497		2015-11-03 14:44:00 -06:00
..
core.c	kmod/core: fix crash with !CONFIG_DEBUG_SET_MODULE_RONX	2015-11-03 14:44:00 -06:00
kpatch.h	allow patched modules to call external functions	2014-10-06 23:16:13 -05:00
Makefile	add support for shadow variables	2014-09-08 13:36:37 -05:00
shadow.c	kpatch-build: fix shadow_get function	2015-10-12 17:15:00 +08:00