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| author |   Toshi Kani <toshi.kani@hpe.com> | 2018-06-27 08:13:46 -0600 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2018-07-04 21:37:08 +0200 |
| commit | f967db0b9ed44ec3057a28f3b28efc51df51b835 (patch) | |
| tree | 2a1e1aba7101d7ccf64a42ac58197a6c1f55f135 /lib/ioremap.c | |
| parent | Linux 4.18-rc3 (diff) | |
| download | linux-dev-f967db0b9ed44ec3057a28f3b28efc51df51b835.tar.xz linux-dev-f967db0b9ed44ec3057a28f3b28efc51df51b835.zip | |
x86/mm: Disable ioremap free page handling on x86-PAE
ioremap() supports pmd mappings on x86-PAE. However, kernel's pmd
tables are not shared among processes on x86-PAE. Therefore, any
update to sync'd pmd entries need re-syncing. Freeing a pte page
also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one().
Disable free page handling on x86-PAE. pud_free_pmd_page() and
pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present.
This assures that ioremap() does not update sync'd pmd entries at the
cost of falling back to pte mappings.
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: cpandya@codeaurora.org
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-2-toshi.kani@hpe.com
Diffstat (limited to 'lib/ioremap.c')
0 files changed, 0 insertions, 0 deletions