linux/arch/riscv/mm
Jisheng Zhang 8a4102a0cf
riscv: mm: Fix W+X mappings at boot
When the kernel mapping was moved the last 2GB of the address space,
(__va(PFN_PHYS(max_low_pfn))) is much smaller than the .data section
start address, the last set_memory_nx() in protect_kernel_text_data()
will fail, thus the .data section is still mapped as W+X. This results
in below W+X mapping waring at boot. Fix it by passing the correct
.data section page num to the set_memory_nx().

[    0.396516] ------------[ cut here ]------------
[    0.396889] riscv/mm: Found insecure W+X mapping at address (____ptrval____)/0xffffffff80c00000
[    0.398347] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/ptdump.c:258 note_page+0x244/0x24a
[    0.398964] Modules linked in:
[    0.399459] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc1+ #14
[    0.400003] Hardware name: riscv-virtio,qemu (DT)
[    0.400591] epc : note_page+0x244/0x24a
[    0.401368]  ra : note_page+0x244/0x24a
[    0.401772] epc : ffffffff80007c86 ra : ffffffff80007c86 sp : ffffffe000e7bc30
[    0.402304]  gp : ffffffff80caae88 tp : ffffffe000e70000 t0 : ffffffff80cb80cf
[    0.402800]  t1 : ffffffff80cb80c0 t2 : 0000000000000000 s0 : ffffffe000e7bc80
[    0.403310]  s1 : ffffffe000e7bde8 a0 : 0000000000000053 a1 : ffffffff80c83ff0
[    0.403805]  a2 : 0000000000000010 a3 : 0000000000000000 a4 : 6c7e7a5137233100
[    0.404298]  a5 : 6c7e7a5137233100 a6 : 0000000000000030 a7 : ffffffffffffffff
[    0.404849]  s2 : ffffffff80e00000 s3 : 0000000040000000 s4 : 0000000000000000
[    0.405393]  s5 : 0000000000000000 s6 : 0000000000000003 s7 : ffffffe000e7bd48
[    0.405935]  s8 : ffffffff81000000 s9 : ffffffffc0000000 s10: ffffffe000e7bd48
[    0.406476]  s11: 0000000000001000 t3 : 0000000000000072 t4 : ffffffffffffffff
[    0.407016]  t5 : 0000000000000002 t6 : ffffffe000e7b978
[    0.407435] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003
[    0.408052] Call Trace:
[    0.408343] [<ffffffff80007c86>] note_page+0x244/0x24a
[    0.408855] [<ffffffff8010c5a6>] ptdump_hole+0x14/0x1e
[    0.409263] [<ffffffff800f65c6>] walk_pgd_range+0x2a0/0x376
[    0.409690] [<ffffffff800f6828>] walk_page_range_novma+0x4e/0x6e
[    0.410146] [<ffffffff8010c5f8>] ptdump_walk_pgd+0x48/0x78
[    0.410570] [<ffffffff80007d66>] ptdump_check_wx+0xb4/0xf8
[    0.410990] [<ffffffff80006738>] mark_rodata_ro+0x26/0x2e
[    0.411407] [<ffffffff8031961e>] kernel_init+0x44/0x108
[    0.411814] [<ffffffff80002312>] ret_from_exception+0x0/0xc
[    0.412309] ---[ end trace 7ec3459f2547ea83 ]---
[    0.413141] Checked W+X mappings: failed, 512 W+X pages found

Fixes: 2bfc6cd81b ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-01 21:15:09 -07:00
..
cacheflush.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
context.c RISC-V: Implement ASID allocator 2021-02-18 23:18:06 -08:00
extable.c riscv: abstract out CSR names for supervisor vs machine mode 2019-11-05 09:20:42 -08:00
fault.c RISC-V Patches for the 5.13 Merge Window, Part 1 2021-05-06 09:24:18 -07:00
hugetlbpage.c hugetlbfs: remove hugetlb_add_hstate() warning for existing hstate 2020-06-03 20:09:46 -07:00
init.c riscv: mm: Fix W+X mappings at boot 2021-06-01 21:15:09 -07:00
kasan_init.c RISC-V Patches for the 5.13 Merge Window, Part 1 2021-05-06 09:24:18 -07:00
Makefile riscv: Fixup patch_text panic in ftrace 2021-01-14 15:09:04 -08:00
pageattr.c RISC-V Patches for the 5.11 Merge Window, Part 1 2020-12-18 10:43:07 -08:00
physaddr.c riscv: Move kernel mapping outside of linear mapping 2021-04-26 08:25:04 -07:00
ptdump.c riscv: Remove 32b kernel mapping from page table dump 2021-05-01 08:53:32 -07:00
tlbflush.c RISC-V: Issue a tlb page flush if possible 2019-10-29 11:32:18 -07:00