Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Remove usermode driver (UMD) framework (Thomas Weißschuh)

 - Introduce Strongly Connected Component (SCC) in the verifier to
   detect loops and refine register liveness (Eduard Zingerman)

 - Allow 'void *' cast using bpf_rdonly_cast() and corresponding
   '__arg_untrusted' for global function parameters (Eduard Zingerman)

 - Improve precision for BPF_ADD and BPF_SUB operations in the verifier
   (Harishankar Vishwanathan)

 - Teach the verifier that constant pointer to a map cannot be NULL
   (Ihor Solodrai)

 - Introduce BPF streams for error reporting of various conditions
   detected by BPF runtime (Kumar Kartikeya Dwivedi)

 - Teach the verifier to insert runtime speculation barrier (lfence on
   x86) to mitigate speculative execution instead of rejecting the
   programs (Luis Gerhorst)

 - Various improvements for 'veristat' (Mykyta Yatsenko)

 - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
   improve bug detection by syzbot (Paul Chaignon)

 - Support BPF private stack on arm64 (Puranjay Mohan)

 - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
   node (Song Liu)

 - Introduce kfuncs for read-only string opreations (Viktor Malik)

 - Implement show_fdinfo() for bpf_links (Tao Chen)

 - Reduce verifier's stack consumption (Yonghong Song)

 - Implement mprog API for cgroup-bpf programs (Yonghong Song)

* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
  selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
  selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
  bpf: Add log for attaching tracing programs to functions in deny list
  bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
  bpf: Fix various typos in verifier.c comments
  bpf: Add third round of bounds deduction
  selftests/bpf: Test invariants on JSLT crossing sign
  selftests/bpf: Test cross-sign 64bits range refinement
  selftests/bpf: Update reg_bound range refinement logic
  bpf: Improve bounds when s64 crosses sign boundary
  bpf: Simplify bounds refinement from s32
  selftests/bpf: Enable private stack tests for arm64
  bpf, arm64: JIT support for private stack
  bpf: Move bpf_jit_get_prog_name() to core.c
  bpf, arm64: Fix fp initialization for exception boundary
  umd: Remove usermode driver framework
  bpf/preload: Don't select USERMODE_DRIVER
  selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
  selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
  selftests/bpf: Increase xdp data size for arm64 64K page size
  ...

1 files changed, 23 insertions, 0 deletions

diff --git a/kernel/bpf/rqspinlock.c b/kernel/bpf/rqspinlock.c
index 338305c8852c..5ab354d55d82 100644
--- a/kernel/bpf/rqspinlock.c
+++ b/kernel/bpf/rqspinlock.c
@@ -666,6 +666,27 @@ EXPORT_SYMBOL_GPL(resilient_queued_spin_lock_slowpath);
 
 __bpf_kfunc_start_defs();
 
+static void bpf_prog_report_rqspinlock_violation(const char *str, void *lock, bool irqsave)
+{
+	struct rqspinlock_held *rqh = this_cpu_ptr(&rqspinlock_held_locks);
+	struct bpf_stream_stage ss;
+	struct bpf_prog *prog;
+
+	prog = bpf_prog_find_from_stack();
+	if (!prog)
+		return;
+	bpf_stream_stage(ss, prog, BPF_STDERR, ({
+		bpf_stream_printk(ss, "ERROR: %s for bpf_res_spin_lock%s\n", str, irqsave ? "_irqsave" : "");
+		bpf_stream_printk(ss, "Attempted lock   = 0x%px\n", lock);
+		bpf_stream_printk(ss, "Total held locks = %d\n", rqh->cnt);
+		for (int i = 0; i < min(RES_NR_HELD, rqh->cnt); i++)
+			bpf_stream_printk(ss, "Held lock[%2d] = 0x%px\n", i, rqh->locks[i]);
+		bpf_stream_dump_stack(ss);
+	}));
+}
+
+#define REPORT_STR(ret) ({ (ret) == -ETIMEDOUT ? "Timeout detected" : "AA or ABBA deadlock detected"; })
+
 __bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock)
 {
 	int ret;
@@ -676,6 +697,7 @@ __bpf_kfunc int bpf_res_spin_lock(struct bpf_res_spin_lock *lock)
 	preempt_disable();
 	ret = res_spin_lock((rqspinlock_t *)lock);
 	if (unlikely(ret)) {
+		bpf_prog_report_rqspinlock_violation(REPORT_STR(ret), lock, false);
 		preempt_enable();
 		return ret;
 	}
@@ -698,6 +720,7 @@ __bpf_kfunc int bpf_res_spin_lock_irqsave(struct bpf_res_spin_lock *lock, unsign
 	local_irq_save(flags);
 	ret = res_spin_lock((rqspinlock_t *)lock);
 	if (unlikely(ret)) {
+		bpf_prog_report_rqspinlock_violation(REPORT_STR(ret), lock, true);
 		local_irq_restore(flags);
 		preempt_enable();
 		return ret;