[PATCH 08/20] signal/sparc: In setup_tsb_params convert open coded BUG into BUG

Eric W. Biederman
2021-10-20T17:45:12Z

The function setup_tsb_params has exactly one caller tsb_grow. The
function tsb_grow passes in a tsb_bytes value that is between 8192 and
1048576 inclusive, and is guaranteed to be a power of 2. The function
setup_tsb_params verifies this property with a switch statement and
then prints an error and causes the task to exit if this is not true.

In practice that print statement can never be reached because tsb_grow
never passes in a bad tsb_size. So if tsb_size ever gets a bad value
that is a kernel bug.

So replace the do_exit which is effectively an open coded version of
BUG() with an actuall call to BUG(). Making it clearer that this
is a case that can never, and should never happen.

Cc: David Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
arch/sparc/mm/tsb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/sparc/mm/tsb.c b/arch/sparc/mm/tsb.c
index 0dce4b7ff73e..912205787161 100644
--- a/arch/sparc/mm/tsb.c
+++ b/arch/sparc/mm/tsb.c
@@ -266,7 +266,7 @@ static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsign
default:
printk(KERN_ERR "TSB[%s:%d]: Impossible TSB size %lu, killing process.\n",
current->comm, current->pid, tsb_bytes);
- do_exit(SIGSEGV);
+ BUG();
}
tte |= pte_sz_bits(page_sz);

--
2.20.1