Clear the IT state when invoking a Thumb-2 signal handler

If a process is interrupted during an If-Then block and a signal is
invoked, the ITSTATE bits must be cleared otherwise the handler would
not run correctly.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Joseph S. Myers <joseph@codesourcery.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 80b8b5c7e07a..442b87476f97 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -426,9 +426,13 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
                  */
                 thumb = handler & 1;
 
-                if (thumb)
+                if (thumb) {
                         cpsr |= PSR_T_BIT;
-                else
+#if __LINUX_ARM_ARCH__ >= 7
+                        /* clear the If-Then Thumb-2 execution state */
+                        cpsr &= ~PSR_IT_MASK;
+#endif
+                } else
                         cpsr &= ~PSR_T_BIT;
         }
 #endif