linux_dsm_epyc7002/arch/x86
Dave Hansen 60f583d56a x86: Do not try to sync identity map for non-mapped pages
kernel_map_sync_memtype() is called from a variety of contexts.  The
pat.c code that calls it seems to ensure that it is not called for
non-ram areas by checking via pat_pagerange_is_ram().  It is important
that it only be called on the actual identity map because there *IS*
no map to sync for highmem pages, or for memory holes.

The ioremap.c uses are not as careful as those from pat.c, and call
kernel_map_sync_memtype() on PCI space which is in the middle of the
kernel identity map _range_, but is not actually mapped.

This patch adds a check to kernel_map_sync_memtype() which probably
duplicates some of the checks already in pat.c.  But, it is necessary
for the ioremap.c uses and shouldn't hurt other callers.

I have reproduced this bug and this patch fixes it for me and the
original bug reporter:

	https://lkml.org/lkml/2013/2/5/396

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20130307163151.D9B58C4E@kernel.stglabs.ibm.com
Signed-off-by: Dave Hansen <dave@sr71.net>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2013-03-07 13:23:28 -08:00
..
boot
configs
crypto
ia32
include x86, doc: Be explicit about what the x86 struct boot_params requires 2013-03-06 20:34:43 -08:00
kernel
kvm
lguest
lib
math-emu
mm x86: Do not try to sync identity map for non-mapped pages 2013-03-07 13:23:28 -08:00
net
oprofile
pci
platform
power
realmode
syscalls
tools
um
vdso
video
xen
.gitignore
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Kconfig.debug
Makefile
Makefile_32.cpu
Makefile.um