From: Mykyta Yatsenko Add __force annotations to casts that convert between __user and kernel address spaces. These casts are intentional: - In bpf_send_signal_common(), the value is stored in si_value.sival_ptr which is typed as void __user *, but the value comes from a BPF program parameter. - In the bpf_*_dynptr() kfuncs, user pointers are cast to const void * before being passed to copy helper functions that correctly handle the user address space through copy_from_user variants. Without __force, sparse reports: warning: cast removes address space '__user' of expression Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202601131740.6C3BdBaB-lkp@intel.com/ Signed-off-by: Mykyta Yatsenko --- kernel/trace/bpf_trace.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 6e076485bf70..c9ada367a202 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -830,7 +830,7 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type, struct task_struc info.si_code = SI_KERNEL; info.si_pid = 0; info.si_uid = 0; - info.si_value.sival_ptr = (void *)(unsigned long)value; + info.si_value.sival_ptr = (void __user __force *)(unsigned long)value; siginfo = &info; } @@ -3517,7 +3517,7 @@ __bpf_kfunc int bpf_send_signal_task(struct task_struct *task, int sig, enum pid __bpf_kfunc int bpf_probe_read_user_dynptr(struct bpf_dynptr *dptr, u64 off, u64 size, const void __user *unsafe_ptr__ign) { - return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, + return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign, copy_user_data_nofault, NULL); } @@ -3531,7 +3531,7 @@ __bpf_kfunc int bpf_probe_read_kernel_dynptr(struct bpf_dynptr *dptr, u64 off, __bpf_kfunc int bpf_probe_read_user_str_dynptr(struct bpf_dynptr *dptr, u64 off, u64 size, const void __user *unsafe_ptr__ign) { - return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, + return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign, copy_user_str_nofault, NULL); } @@ -3545,14 +3545,14 @@ __bpf_kfunc int bpf_probe_read_kernel_str_dynptr(struct bpf_dynptr *dptr, u64 of __bpf_kfunc int bpf_copy_from_user_dynptr(struct bpf_dynptr *dptr, u64 off, u64 size, const void __user *unsafe_ptr__ign) { - return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, + return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign, copy_user_data_sleepable, NULL); } __bpf_kfunc int bpf_copy_from_user_str_dynptr(struct bpf_dynptr *dptr, u64 off, u64 size, const void __user *unsafe_ptr__ign) { - return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, + return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign, copy_user_str_sleepable, NULL); } @@ -3560,7 +3560,7 @@ __bpf_kfunc int bpf_copy_from_user_task_dynptr(struct bpf_dynptr *dptr, u64 off, u64 size, const void __user *unsafe_ptr__ign, struct task_struct *tsk) { - return __bpf_dynptr_copy(dptr, off, size, (const void *)unsafe_ptr__ign, + return __bpf_dynptr_copy(dptr, off, size, (const void __force *)unsafe_ptr__ign, copy_user_data_sleepable, tsk); } @@ -3568,7 +3568,7 @@ __bpf_kfunc int bpf_copy_from_user_task_str_dynptr(struct bpf_dynptr *dptr, u64 u64 size, const void __user *unsafe_ptr__ign, struct task_struct *tsk) { - return __bpf_dynptr_copy_str(dptr, off, size, (const void *)unsafe_ptr__ign, + return __bpf_dynptr_copy_str(dptr, off, size, (const void __force *)unsafe_ptr__ign, copy_user_str_sleepable, tsk); } -- 2.52.0