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path: root/drivers/char/hw_random/via-rng.c
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Diffstat (limited to 'drivers/char/hw_random/via-rng.c')
-rw-r--r--drivers/char/hw_random/via-rng.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
index f7feae4ebb5e..128202e18fc9 100644
--- a/drivers/char/hw_random/via-rng.c
+++ b/drivers/char/hw_random/via-rng.c
@@ -31,6 +31,7 @@
#include <asm/io.h>
#include <asm/msr.h>
#include <asm/cpufeature.h>
+#include <asm/i387.h>
#define PFX KBUILD_MODNAME ": "
@@ -67,16 +68,23 @@ enum {
* Another possible performance boost may come from simply buffering
* until we have 4 bytes, thus returning a u32 at a time,
* instead of the current u8-at-a-time.
+ *
+ * Padlock instructions can generate a spurious DNA fault, so
+ * we have to call them in the context of irq_ts_save/restore()
*/
static inline u32 xstore(u32 *addr, u32 edx_in)
{
u32 eax_out;
+ int ts_state;
+
+ ts_state = irq_ts_save();
asm(".byte 0x0F,0xA7,0xC0 /* xstore %%edi (addr=%0) */"
:"=m"(*addr), "=a"(eax_out)
:"D"(addr), "d"(edx_in));
+ irq_ts_restore(ts_state);
return eax_out;
}