diff options
| author | Atsushi Kumagai <ats-kumagai@wm.jp.nec.com> | 2016-05-26 15:49:59 +0900 |
|---|---|---|
| committer | Atsushi Kumagai <ats-kumagai@wm.jp.nec.com> | 2016-06-07 13:01:46 +0900 |
| commit | ecf7a13945bf4f68328a015732d476b3ef9f0162 (patch) | |
| tree | fbd21dca6eb2cbb86a1d8b847e39221502ea18bf /arch | |
| parent | 11a6dae4a39b52237ad2cd6e25492c7d1438ea8f (diff) | |
[PATCH] Skip null entries to walk page tables correctly
If there is a null page table entry, the current code try
to read 0x0 for -e option as lower page table although it
should be skipped. This behavior will cause unexpected results.
Especially if pfn:0 is on a memory hole or excluded, this
feature will be disabled completely.
Signed-off-by: Atsushi Kumagai <ats-kumagai@wm.jp.nec.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86_64.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86_64.c b/arch/x86_64.c index c51e26e..ddf7be6 100644 --- a/arch/x86_64.c +++ b/arch/x86_64.c @@ -537,6 +537,8 @@ find_vmemmap_x86_64() } /* mask the pgd entry for the address of the pud page */ pud_addr &= PMASK; + if (pud_addr == 0) + continue; /* read the entire pud page */ if (!readmem(PADDR, (unsigned long long)pud_addr, (void *)pud_page, PTRS_PER_PUD * sizeof(unsigned long))) { @@ -549,6 +551,8 @@ find_vmemmap_x86_64() pudindex < PTRS_PER_PUD; pudindex++, pudp++) { pmd_addr = *pudp & PMASK; /* read the entire pmd page */ + if (pmd_addr == 0) + continue; if (!readmem(PADDR, pmd_addr, (void *)pmd_page, PTRS_PER_PMD * sizeof(unsigned long))) { ERRMSG("Can't get pud entry for slot %ld.\n", pudindex); |