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author | Juergen Gross <jgross@suse.com> | 2018-11-07 20:01:00 +0300 |
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committer | Juergen Gross <jgross@suse.com> | 2018-11-09 10:16:55 +0300 |
commit | 1457d8cf7664f34c4ba534c1073821a559a2f6f9 (patch) | |
tree | cb6435f561fe83789ecd108c5812e1e5667ae900 /arch/x86/xen | |
parent | 6cc4a0863c9709c512280c64e698d68443ac8053 (diff) | |
download | linux-1457d8cf7664f34c4ba534c1073821a559a2f6f9.tar.xz |
x86/xen: fix pv boot
Commit 9da3f2b7405440 ("x86/fault: BUG() when uaccess helpers fault on
kernel addresses") introduced a regression for booting Xen PV guests.
Xen PV guests are using __put_user() and __get_user() for accessing the
p2m map (physical to machine frame number map) as accesses might fail
in case of not populated areas of the map.
With above commit using __put_user() and __get_user() for accessing
kernel pages is no longer valid. So replace the Xen hack by adding
appropriate p2m access functions using the default fixup handler.
Fixes: 9da3f2b7405440 ("x86/fault: BUG() when uaccess helpers fault on kernel addresses")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/xen')
-rw-r--r-- | arch/x86/xen/p2m.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c index d6d74efd8912..4fe84436d5a7 100644 --- a/arch/x86/xen/p2m.c +++ b/arch/x86/xen/p2m.c @@ -656,8 +656,7 @@ bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) /* * The interface requires atomic updates on p2m elements. - * xen_safe_write_ulong() is using __put_user which does an atomic - * store via asm(). + * xen_safe_write_ulong() is using an atomic store via asm(). */ if (likely(!xen_safe_write_ulong(xen_p2m_addr + pfn, mfn))) return true; |