diff options
| author | Juergen Gross | 2018-06-13 11:58:06 +0200 |
|---|---|---|
| committer | Boris Ostrovsky | 2018-08-07 11:37:01 -0400 |
| commit | cd9139220b87f40ea83858de1d6436c639376ce7 (patch) | |
| tree | 3f6e21d752354b5773dc6289246206498094a10d | |
| parent | 405c018a25fe464dc68057bbc8014a58f2bd4422 (diff) | |
xen: don't use privcmd_call() from xen_mc_flush()
Using privcmd_call() for a singleton multicall seems to be wrong, as
privcmd_call() is using stac()/clac() to enable hypervisor access to
Linux user space.
Even if currently not a problem (pv domains can't use SMAP while HVM
and PVH domains can't use multicalls) things might change when
PVH dom0 support is added to the kernel.
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
| -rw-r--r-- | arch/x86/include/asm/xen/hypercall.h | 25 | ||||
| -rw-r--r-- | arch/x86/xen/multicalls.c | 6 |
2 files changed, 22 insertions, 9 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index bfd882617613..6b2f90a0b149 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -209,24 +209,37 @@ extern struct { char _entry[32]; } hypercall_page[]; }) static inline long -privcmd_call(unsigned call, - unsigned long a1, unsigned long a2, - unsigned long a3, unsigned long a4, - unsigned long a5) +xen_single_call(unsigned int call, + unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4, + unsigned long a5) { __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); - stac(); asm volatile(CALL_NOSPEC : __HYPERCALL_5PARAM : [thunk_target] "a" (&hypercall_page[call]) : __HYPERCALL_CLOBBER5); - clac(); return (long)__res; } +static inline long +privcmd_call(unsigned int call, + unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4, + unsigned long a5) +{ + long res; + + stac(); + res = xen_single_call(call, a1, a2, a3, a4, a5); + clac(); + + return res; +} + static inline int HYPERVISOR_set_trap_table(struct trap_info *table) { diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index dc502ca8263e..2bce7958ce8b 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -80,9 +80,9 @@ void xen_mc_flush(void) and just do the call directly. */ mc = &b->entries[0]; - mc->result = privcmd_call(mc->op, - mc->args[0], mc->args[1], mc->args[2], - mc->args[3], mc->args[4]); + mc->result = xen_single_call(mc->op, mc->args[0], mc->args[1], + mc->args[2], mc->args[3], + mc->args[4]); ret = mc->result < 0; break; |