diff options
author | Arnd Bergmann <arnd@arndb.de> | 2019-03-04 21:52:39 +0100 |
---|---|---|
committer | Juergen Gross <jgross@suse.com> | 2019-03-05 12:07:32 +0100 |
commit | b1ddd406cd1e9bb51fa90d03ee562c832e38eb52 (patch) | |
tree | 01ada3c648984bced35c52dcca18c03df594e2f6 /arch/x86/include/asm/xen | |
parent | 85eb278c1899f78d1429b45ffa84039d9011cb55 (diff) | |
download | linux-stable-b1ddd406cd1e9bb51fa90d03ee562c832e38eb52.tar.gz linux-stable-b1ddd406cd1e9bb51fa90d03ee562c832e38eb52.tar.bz2 linux-stable-b1ddd406cd1e9bb51fa90d03ee562c832e38eb52.zip |
xen: remove pre-xen3 fallback handlers
The legacy hypercall handlers were originally added with
a comment explaining that "copying the argument structures in
HYPERVISOR_event_channel_op() and HYPERVISOR_physdev_op() into the local
variable is sufficiently safe" and only made sure to not write
past the end of the argument structure, the checks in linux/string.h
disagree with that, when link-time optimizations are used:
In function 'memcpy',
inlined from 'pirq_query_unmask' at drivers/xen/fallback.c:53:2,
inlined from '__startup_pirq' at drivers/xen/events/events_base.c:529:2,
inlined from 'restore_pirqs' at drivers/xen/events/events_base.c:1439:3,
inlined from 'xen_irq_resume' at drivers/xen/events/events_base.c:1581:2:
include/linux/string.h:350:3: error: call to '__read_overflow2' declared with attribute error: detected read beyond size of object passed as 2nd parameter
__read_overflow2();
^
Further research turned out that only Xen 3.0.2 or earlier required the
fallback at all, while all versions in use today don't need it.
As far as I can tell, it is not even possible to run a mainline kernel
on those old Xen releases, at the time when they were in use, only
a patched kernel was supported anyway.
Fixes: cf47a83fb06e ("xen/hypercall: fix hypercall fallback code for very old hypervisors")
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/include/asm/xen')
-rw-r--r-- | arch/x86/include/asm/xen/hypercall.h | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index ef05bea7010d..de6f0d59a24f 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -332,15 +332,11 @@ HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val, return _hypercall4(int, update_va_mapping, va, new_val.pte, new_val.pte >> 32, flags); } -extern int __must_check xen_event_channel_op_compat(int, void *); static inline int HYPERVISOR_event_channel_op(int cmd, void *arg) { - int rc = _hypercall2(int, event_channel_op, cmd, arg); - if (unlikely(rc == -ENOSYS)) - rc = xen_event_channel_op_compat(cmd, arg); - return rc; + return _hypercall2(int, event_channel_op, cmd, arg); } static inline int @@ -355,15 +351,10 @@ HYPERVISOR_console_io(int cmd, int count, char *str) return _hypercall3(int, console_io, cmd, count, str); } -extern int __must_check xen_physdev_op_compat(int, void *); - static inline int HYPERVISOR_physdev_op(int cmd, void *arg) { - int rc = _hypercall2(int, physdev_op, cmd, arg); - if (unlikely(rc == -ENOSYS)) - rc = xen_physdev_op_compat(cmd, arg); - return rc; + return _hypercall2(int, physdev_op, cmd, arg); } static inline int |