From e7cc4173115347bcdaa5de2824dd46ef2c58425f Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Thu, 30 Apr 2015 21:19:55 -0700 Subject: [PATCH] signals, ptrace, sched: Fix a misaligned load inside ptrace_attach() The misaligned load exception arises when running ptrace_attach() on the RISC-V (which hasn't been upstreamed yet). The problem is that wait_on_bit() takes a void* but then proceeds to call test_bit(), which takes a long*. This allows an int-aligned pointer to be passed to test_bit(), which promptly fails. This will manifest on any other asm-generic port where unaligned loads trap, where sizeof(long) > sizeof(int), and where task_struct.jobctl ends up not being long-aligned. This patch changes task_struct.jobctl to be a long, which ensures it has the correct alignment. Signed-off-by: Palmer Dabbelt Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Chris Metcalf Cc: Andrew Morton Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Cc: bobby.prani@gmail.com Cc: oleg@redhat.com Cc: paulmck@linux.vnet.ibm.com Cc: richard@nod.at Cc: vdavydov@parallels.com Link: http://lkml.kernel.org/r/1430453997-32459-2-git-send-email-palmer@dabbelt.com Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 4f066cb625ad..fb650a2f4a73 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1374,7 +1374,7 @@ struct task_struct { int exit_state; int exit_code, exit_signal; int pdeath_signal; /* The signal sent when the parent dies */ - unsigned int jobctl; /* JOBCTL_*, siglock protected */ + unsigned long jobctl; /* JOBCTL_*, siglock protected */ /* Used for emulating ABI behavior of previous Linux versions */ unsigned int personality; -- 2.20.1