[linux-morello] Re: [PATCH v2] kernel: kcmp: Fix syscall ABI for purecap

On 02/11/2022 10:46, carsten.haitzler@foss.arm.com wrote:

From: Carsten Haitzler carsten.haitzler@foss.arm.com

Fix the kcmp syscall (when CONFIG_CHECKPOINT_RESTORE is enabled) for the case that the idx arguments might be pointers (capabilites) passed in. One of the kcmp types uses idx2 to carry a capability pointer to extended structure information copied in from userspace.

Signed-off-by: Carsten Haitzler carsten.haitzler@foss.arm.com

kernel/kcmp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/kcmp.c b/kernel/kcmp.c index 5353edfad8e1..d59f74c68c93 100644 --- a/kernel/kcmp.c +++ b/kernel/kcmp.c @@ -133,7 +133,7 @@ static int kcmp_epoll_target(struct task_struct *task1, #endif SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,

• unsigned long, idx1, unsigned long, idx2)
  

• unsigned long, idx1, user_uintptr_t, idx2)
  

  { struct task_struct *task1, *task2; int ret;

@@ -204,7 +204,8 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type, #endif break; case KCMP_EPOLL_TFD:

• ret = kcmp_epoll_target(task1, task2, idx1, (void *)idx2);
  

• ret = kcmp_epoll_target(task1, task2, idx1,
  

• 			(struct kcmp_epoll_slot __user *)idx2);
  

  break; default: ret = -EINVAL;

Both patches now applied on next, thanks!

Kevin