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>

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 8acaf4e384c0fc45612819f18b97cfe1ce3e1771..a86d7cc2c2d82fa7d0e5c13d1f3188efcd660fba 100644 (file)
--- 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");