[linux-morello] [PATCH v2] mm/mmap: disable brk in purecap

brk is not implemented in purecap, return -ENOSYS when not in compat.

Signed-off-by: Teo Couprie Diaz teo.coupriediaz@arm.com --- Thanks Tudor for providing the code snippet, making it much more clear than my original ideas. v2: Fix style and format issues.

mm/mmap.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/mm/mmap.c b/mm/mmap.c index ce282f9d9f8e..5de8e48b66b7 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -202,6 +202,11 @@ SYSCALL_DEFINE1(brk, unsigned long, brk) bool downgraded = false; LIST_HEAD(uf);

+#ifdef CONFIG_CHERI_PURECAP_UABI + if (!in_compat_syscall()) + return -ENOSYS; +#endif + if (mmap_write_lock_killable(mm)) return -EINTR;

base-commit: 3deb26714719d5068f5ef5d0fa9bc457c3cef6c1