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b14b8b1ed0
Since the conversion to generic ptdump we see crashes on 64-bit:
BUG: Unable to handle kernel data access on read at 0xc0eeff7f00000000
Faulting instruction address: 0xc00000000045e5fc
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP __walk_page_range+0x2bc/0xce0
LR __walk_page_range+0x240/0xce0
Call Trace:
__walk_page_range+0x240/0xce0 (unreliable)
walk_page_range_novma+0x74/0xb0
ptdump_walk_pgd+0x98/0x170
ptdump_check_wx+0x88/0xd0
mark_rodata_ro+0x48/0x80
kernel_init+0x74/0x1a0
ret_from_kernel_thread+0x5c/0x64
What's happening is that have walked off the end of the kernel page
tables, and started dereferencing junk values.
That happens because we initialised the ptdump_range to span all the way
up to 0xffffffffffffffff:
static struct ptdump_range ptdump_range[] __ro_after_init = {
{TASK_SIZE_MAX, ~0UL},
But the kernel page tables don't span that far. So on 64-bit set the end
of the range to be the address immediately past the end of the kernel
page tables, to limit the page table walk to valid addresses.
Fixes:
|
||
|---|---|---|
| .. | ||
| book3s32 | ||
| book3s64 | ||
| kasan | ||
| nohash | ||
| ptdump | ||
| cacheflush.c | ||
| copro_fault.c | ||
| dma-noncoherent.c | ||
| drmem.c | ||
| fault.c | ||
| hugetlbpage.c | ||
| init-common.c | ||
| init_32.c | ||
| init_64.c | ||
| ioremap.c | ||
| ioremap_32.c | ||
| ioremap_64.c | ||
| maccess.c | ||
| Makefile | ||
| mem.c | ||
| mmap.c | ||
| mmu_context.c | ||
| mmu_decl.h | ||
| numa.c | ||
| pageattr.c | ||
| pgtable-frag.c | ||
| pgtable.c | ||
| pgtable_32.c | ||
| pgtable_64.c | ||
| slice.c | ||