Messages in this thread | | | Date | Mon, 24 Oct 2022 11:27:30 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v2] x86/mm: Refuse W^X violations |
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On Mon, 29 Aug 2022 12:18:03 +0200 Peter Zijlstra <peterz@infradead.org> wrote:
> x86 has STRICT_*_RWX, but not even a warning when someone violates it. > > Add this warning and fully refuse the transition. > > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
So, this now triggers on enabling function tracing at boot up:
"ftrace=function"
This:
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 Kernel/User page tables isolation: enabled ftrace: allocating 68738 entries in 269 pages ftrace: allocated 269 pages with 4 groups Starting tracer 'function' ------------[ cut here ]------------ CPA detected W^X violation: 8000000000000063 -> 0000000000000063 range: 0xffffffffc0013000 - 0xffffffffc0013fff PFN 10031b WARNING: CPU: 0 PID: 0 at arch/x86/mm/pat/set_memory.c:609 verify_rwx+0x61/0x6d Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.1.0-rc1-test+ #3 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 RIP: 0010:verify_rwx+0x61/0x6d Code: e5 01 00 75 27 49 c1 e0 0c 48 89 d1 48 89 fe 48 c7 c7 5b b3 92 84 4e 8d 44 02 ff 48 89 da c6 05 71 29 e5 01 01 e8 35 90 e2 00 <0f> 0b 48 89 d8 5b 5d e9 6f 95 1a 01 0f 1f 44 00 00 55 48 89 e5 53 RSP: 0000:ffffffff84c03b08 EFLAGS: 00010086 RAX: 0000000000000000 RBX: 0000000000000063 RCX: 0000000000000003 RDX: 0000000000000003 RSI: ffffffff84c039b0 RDI: 0000000000000001 RBP: ffffffff84c03b10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000025 R12: ffff8e730031c098 R13: 000000000010031b R14: 800000010031b063 R15: 8000000000000063 FS: 0000000000000000(0000) GS:ffff8e7416a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8e73fd801000 CR3: 00000001fcc22001 CR4: 00000000000606f0 Call Trace: <TASK> __change_page_attr_set_clr+0x146/0x8a6 ? __mutex_unlock_slowpath+0x41/0x213 ? mutex_unlock+0x12/0x18 ? _vm_unmap_aliases+0x126/0x136 change_page_attr_set_clr+0x135/0x268 ? find_vmap_area+0x32/0x3e ? __fentry__+0x10/0x10 change_page_attr_clear.constprop.0+0x16/0x1c set_memory_x+0x2c/0x32 arch_ftrace_update_trampoline+0x218/0x2db ? ftrace_caller_op_ptr+0x17/0x17 ftrace_update_trampoline+0x16/0xa1 ? tracing_gen_ctx+0x1c/0x1c __register_ftrace_function+0x93/0xb2 ftrace_startup+0x21/0xf0 ? tracing_gen_ctx+0x1c/0x1c register_ftrace_function_nolock+0x26/0x40 register_ftrace_function+0x4e/0x143 ? mutex_unlock+0x12/0x18 ? tracing_gen_ctx+0x1c/0x1c function_trace_init+0x7d/0xc3 tracer_init+0x23/0x2c tracing_set_tracer+0x1d5/0x206 register_tracer+0x1c0/0x1e4 init_function_trace+0x90/0x96 early_trace_init+0x25c/0x352 start_kernel+0x424/0x6e4 x86_64_start_reservations+0x24/0x2a x86_64_start_kernel+0x8c/0x95 secondary_startup_64_no_verify+0xe0/0xeb </TASK> ---[ end trace 0000000000000000 ]---
-- Steve
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