linux/arch/x86/mm
Steven Rostedt (Google) a970174d7a x86/mm: Do not verify W^X at boot up
Adding on the kernel command line "ftrace=function" triggered:

  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
  Call Trace:
     __change_page_attr_set_clr+0x146/0x8a6
     change_page_attr_set_clr+0x135/0x268
     change_page_attr_clear.constprop.0+0x16/0x1c
     set_memory_x+0x2c/0x32
     arch_ftrace_update_trampoline+0x218/0x2db
     ftrace_update_trampoline+0x16/0xa1
     __register_ftrace_function+0x93/0xb2
     ftrace_startup+0x21/0xf0
     register_ftrace_function_nolock+0x26/0x40
     register_ftrace_function+0x4e/0x143
     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

This is because at boot up, kernel text is writable, and there's no
reason to do tricks to updated it.  But the verifier does not
distinguish updates at boot up and at run time, and causes a warning at
time of boot.

Add a check for system_state == SYSTEM_BOOTING and allow it if that is
the case.

[ These SYSTEM_BOOTING special cases are all pretty horrid, but the x86
  text_poke() code does some odd things at bootup, forcing this for now
    - Linus ]

Link: https://lore.kernel.org/r/20221024112730.180916b3@gandalf.local.home
Fixes: 652c5bf380 ("x86/mm: Refuse W^X violations")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-10-24 18:05:27 -07:00
..
pat x86/mm: Do not verify W^X at boot up 2022-10-24 18:05:27 -07:00
amdtopology.c x86/mm: Replace nodes_weight() with nodes_empty() where appropriate 2022-04-10 22:35:38 +02:00
cpu_entry_area.c x86/sev: Make the #VC exception stacks part of the default stacks storage 2021-10-06 21:48:27 +02:00
debug_pagetables.c mm: introduce include/linux/pgtable.h 2020-06-09 09:39:13 -07:00
dump_pagetables.c mm: don't include asm/pgtable.h if linux/mm.h is already included 2020-06-09 09:39:13 -07:00
extable.c x86: simplify load_unaligned_zeropad() implementation 2022-08-16 11:03:38 -07:00
fault.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
highmem_32.c x86/mm/highmem: Use generic kmap atomic implementation 2020-11-06 23:14:55 +01:00
hugetlbpage.c mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry 2022-08-08 18:06:43 -07:00
ident_map.c x86/mm/ident_map: Check for errors from ident_pud_init() 2020-10-28 14:48:30 +01:00
init_32.c x86: mm: rename __is_kernel_text() to is_x86_32_kernel_text() 2021-11-09 10:02:51 -08:00
init_64.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
init.c mm/swap: cache maximum swapfile size when init swap 2022-09-26 19:46:05 -07:00
iomap_32.c io-mapping: Cleanup atomic iomap 2020-11-06 23:14:58 +01:00
ioremap.c mm: kmsan: maintain KMSAN metadata for page operations 2022-10-03 14:03:20 -07:00
kasan_init_64.c memblock: use memblock_free for freeing virtual pointers 2021-11-06 13:30:41 -07:00
kaslr.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
kmmio.c x86: Fix various typos in comments 2021-03-18 15:31:53 +01:00
kmsan_shadow.c x86: kmsan: handle CPU entry area 2022-10-03 14:03:26 -07:00
maccess.c x86: Share definition of __is_canonical_address() 2022-02-02 13:11:42 +01:00
Makefile x86: kmsan: handle CPU entry area 2022-10-03 14:03:26 -07:00
mem_encrypt_amd.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
mem_encrypt_boot.S objtool: Update Retpoline validation 2022-06-27 10:33:59 +02:00
mem_encrypt_identity.c x86/sev: Add SEV-SNP feature detection/setup 2022-04-07 16:47:11 +02:00
mem_encrypt.c virtio: replace arch_has_restricted_virtio_memory_access() 2022-06-06 08:22:01 +02:00
mm_internal.h x86/mm: thread pgprot_t through init_memory_mapping() 2020-04-10 15:36:21 -07:00
mmap.c x86/mm/mmap: Fix -Wmissing-prototypes warnings 2020-04-22 20:19:48 +02:00
mmio-mod.c x86: Replace cpumask_weight() with cpumask_empty() where appropriate 2022-04-10 22:35:38 +02:00
numa_32.c x86/mm: Drop deprecated DISCONTIGMEM support for 32-bit 2020-05-28 18:34:30 +02:00
numa_64.c
numa_emulation.c x86/mm: Replace nodes_weight() with nodes_empty() where appropriate 2022-04-10 22:35:38 +02:00
numa_internal.h
numa.c x86/numa: Use cpumask_available instead of hardcoded NULL check 2022-08-03 11:44:57 +02:00
pf_in.c
pf_in.h
pgprot.c x86/mm: move protection_map[] inside the platform 2022-07-17 17:14:38 -07:00
pgtable_32.c mm: remove unneeded includes of <asm/pgalloc.h> 2020-08-07 11:33:26 -07:00
pgtable.c mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG 2022-09-26 19:46:08 -07:00
physaddr.c mm, x86/mm: Untangle address space layout definitions from basic pgtable type definitions 2019-12-10 10:12:55 +01:00
physaddr.h
pkeys.c x86/pkeys: Clarify PKRU_AD_KEY macro 2022-06-07 16:06:33 -07:00
pti.c randstruct: Reorganize Kconfigs and attribute macros 2022-05-08 01:33:06 -07:00
srat.c
testmmiotrace.c remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
tlb.c x86/mm/tlb: Ignore f->new_tlb_gen when zero 2022-07-19 09:04:52 -07:00