diff options
| author | Michael Ellerman <mpe@ellerman.id.au> | 2017-05-16 20:42:53 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-05-17 11:56:33 +1000 |
| commit | bfb9956ab4d8242f4594b5f4bee534b935384fd9 (patch) | |
| tree | 9c51d8a21e963362e7705049d2a61acab84d6159 /arch | |
| parent | d04c02f8aa96d82e4cbe783f85a820aae820e746 (diff) | |
| download | linux-bfb9956ab4d8242f4594b5f4bee534b935384fd9.tar.bz2 | |
powerpc/mm: Fix crash in page table dump with huge pages
The page table dump code doesn't know about huge pages, so currently
it crashes (or walks random memory, usually leading to a crash), if it
finds a huge page. On Book3S we only see huge pages in the Linux page
tables when we're using the P9 Radix MMU.
Teaching the code to properly handle huge pages is a bit more involved,
so for now just prevent the crash.
Cc: stable@vger.kernel.org # v4.10+
Fixes: 8eb07b187000 ("powerpc/mm: Dump linux pagetables")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/mm/dump_linuxpagetables.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/powerpc/mm/dump_linuxpagetables.c b/arch/powerpc/mm/dump_linuxpagetables.c index d659345a98d6..44fe4833910f 100644 --- a/arch/powerpc/mm/dump_linuxpagetables.c +++ b/arch/powerpc/mm/dump_linuxpagetables.c @@ -16,6 +16,7 @@ */ #include <linux/debugfs.h> #include <linux/fs.h> +#include <linux/hugetlb.h> #include <linux/io.h> #include <linux/mm.h> #include <linux/sched.h> @@ -391,7 +392,7 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { addr = start + i * PMD_SIZE; - if (!pmd_none(*pmd)) + if (!pmd_none(*pmd) && !pmd_huge(*pmd)) /* pmd exists */ walk_pte(st, pmd, addr); else @@ -407,7 +408,7 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) for (i = 0; i < PTRS_PER_PUD; i++, pud++) { addr = start + i * PUD_SIZE; - if (!pud_none(*pud)) + if (!pud_none(*pud) && !pud_huge(*pud)) /* pud exists */ walk_pmd(st, pud, addr); else @@ -427,7 +428,7 @@ static void walk_pagetables(struct pg_state *st) */ for (i = 0; i < PTRS_PER_PGD; i++, pgd++) { addr = KERN_VIRT_START + i * PGDIR_SIZE; - if (!pgd_none(*pgd)) + if (!pgd_none(*pgd) && !pgd_huge(*pgd)) /* pgd exists */ walk_pud(st, pgd, addr); else |