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authorJisheng Zhang <jszhang@kernel.org>2021-05-16 17:00:38 +0800
committerPalmer Dabbelt <palmerdabbelt@google.com>2021-06-01 21:15:09 -0700
commit8a4102a0cf07cc76a18f373f6b49485258cc6af4 (patch)
treedc4aeed465e570da398bce8224ca865e0dc80420 /arch
parent6efb943b8616ec53a5e444193dccf1af9ad627b5 (diff)
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: 2bfc6cd81bd17e43 ("riscv: Move kernel mapping outside of linear mapping") Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/riscv/mm/init.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 4faf8bd157ea..4c4c92ce0bb8 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -746,14 +746,18 @@ void __init protect_kernel_text_data(void)
unsigned long init_data_start = (unsigned long)__init_data_begin;
unsigned long rodata_start = (unsigned long)__start_rodata;
unsigned long data_start = (unsigned long)_data;
- unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
+#if defined(CONFIG_64BIT) && defined(CONFIG_MMU)
+ unsigned long end_va = kernel_virt_addr + load_sz;
+#else
+ unsigned long end_va = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
+#endif
set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT);
set_memory_ro(init_text_start, (init_data_start - init_text_start) >> PAGE_SHIFT);
set_memory_nx(init_data_start, (rodata_start - init_data_start) >> PAGE_SHIFT);
/* rodata section is marked readonly in mark_rodata_ro */
set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
- set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
+ set_memory_nx(data_start, (end_va - data_start) >> PAGE_SHIFT);
}
void mark_rodata_ro(void)