um: Fix possible deadlock in sig_handler_common()

We are in atomic context and must not sleep.
Sleeping here is possible since malloc() maps
to kmalloc() with GFP_KERNEL.

Cc: stable@vger.kernel.org
Fixes: b6024b21 ("um: extend fpstate to _xstate to support YMM registers")
Signed-off-by: Richard Weinberger <richard@nod.at>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 8acaf4e384c0..a86d7cc2c2d8 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -15,6 +15,7 @@
 #include <kern_util.h>
 #include <os.h>
 #include <sysdep/mcontext.h>
+#include <um_malloc.h>
 
 void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
         [SIGTRAP]       = relay_signal,
@@ -32,7 +33,7 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
         struct uml_pt_regs *r;
         int save_errno = errno;
 
-        r = malloc(sizeof(struct uml_pt_regs));
+        r = uml_kmalloc(sizeof(struct uml_pt_regs), UM_GFP_ATOMIC);
         if (!r)
                 panic("out of memory");
 
@@ -91,7 +92,7 @@ static void timer_real_alarm_handler(mcontext_t *mc)
 {
         struct uml_pt_regs *regs;
 
-        regs = malloc(sizeof(struct uml_pt_regs));
+        regs = uml_kmalloc(sizeof(struct uml_pt_regs), UM_GFP_ATOMIC);
         if (!regs)
                 panic("out of memory");