s390/signal: always restore saved runtime instrumentation psw bit

Commit "s390: fix handling of runtime instrumentation psw bit" (5ebf250dab)
changed the behavior of setting the runtime instrumentation psw bit.  This
commit restores the original logic:

1. When returning from the signal handler, the runtime instrumentation psw bit
   is restored to its saved state.
2. If the runtime instrumentation psw bit is enabled during the signal handler,
   it is always turned off when leaving the signal handler.  The saved state
   is restored as described in 1.  That also implies that turning on runtime
   instrumentation in the signal handler is only effective while running in the
   signal context.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>

diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index 6e24429784097c034d41072929e446a5ef49cab4..95e7ba0fbb7eb1323b45300c4f6afcae04103dc8 100644 (file)
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -194,7 +194,7 @@ static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
                return -EINVAL;
 
        /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
-       regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+       regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
                (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
                (__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
                (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index fb535874a2464853168c9a9182620acf10e37c74..d8fd508ccd1e180b7679d24939b253d31a56bc26 100644 (file)
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -94,7 +94,7 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
                return -EINVAL;
 
        /* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
-       regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+       regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
                (user_sregs.regs.psw.mask & (PSW_MASK_USER | PSW_MASK_RI));
        /* Check for invalid user address space control. */
        if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)