diff options
author | David S. Miller <davem@davemloft.net> | 2019-11-02 13:12:51 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-11-02 13:54:56 -0700 |
commit | d31e95585ca697fb31440c6fe30113adc85ecfbd (patch) | |
tree | 4936ea0aaa6b2aeeee4db51e3c60d938c9b9ed96 /arch/x86/kernel/head64.c | |
parent | c23fcbbc6aa4e0bb615e8a7f23e1f32aec235a1c (diff) | |
parent | 1204c70d9dcba31164f78ad5d8c88c42335d51f8 (diff) | |
download | linux-d31e95585ca697fb31440c6fe30113adc85ecfbd.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The only slightly tricky merge conflict was the netdevsim because the
mutex locking fix overlapped a lot of driver reload reorganization.
The rest were (relatively) trivial in nature.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/kernel/head64.c')
-rw-r--r-- | arch/x86/kernel/head64.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 29ffa495bd1c..206a4b6144c2 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -222,13 +222,31 @@ unsigned long __head __startup_64(unsigned long physaddr, * we might write invalid pmds, when the kernel is relocated * cleanup_highmap() fixes this up along with the mappings * beyond _end. + * + * Only the region occupied by the kernel image has so far + * been checked against the table of usable memory regions + * provided by the firmware, so invalidate pages outside that + * region. A page table entry that maps to a reserved area of + * memory would allow processor speculation into that area, + * and on some hardware (particularly the UV platform) even + * speculative access to some reserved areas is caught as an + * error, causing the BIOS to halt the system. */ pmd = fixup_pointer(level2_kernel_pgt, physaddr); - for (i = 0; i < PTRS_PER_PMD; i++) { + + /* invalidate pages before the kernel image */ + for (i = 0; i < pmd_index((unsigned long)_text); i++) + pmd[i] &= ~_PAGE_PRESENT; + + /* fixup pages that are part of the kernel image */ + for (; i <= pmd_index((unsigned long)_end); i++) if (pmd[i] & _PAGE_PRESENT) pmd[i] += load_delta; - } + + /* invalidate pages after the kernel image */ + for (; i < PTRS_PER_PMD; i++) + pmd[i] &= ~_PAGE_PRESENT; /* * Fixup phys_base - remove the memory encryption mask to obtain |