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author | Stefan Agner <stefan.agner@toradex.com> | 2019-11-12 13:57:30 +0100 |
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committer | Stefan Agner <stefan.agner@toradex.com> | 2019-11-12 13:57:30 +0100 |
commit | 401bf3f29b1aa6d9ca32bd3252fc9beabe93d80b (patch) | |
tree | 6dd86325823a9b44b6e696acbd077e68c47d3108 /arch/x86/kernel/head64.c | |
parent | 5a9c845fe261dec87f892f3fd3c2e32604d952c0 (diff) | |
parent | b260a0862e3a9fccdac23ec3b783911b098c1c74 (diff) |
Merge tag 'v5.3.10' into toradex_5.3.ytoradex_5.3.y
This is the 5.3.10 stable release
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 |