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authorKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 10:43:19 +0200
committerAlexei Starovoitov <ast@kernel.org>2026-09-04 07:58:36 -0700
commit6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch)
tree58e8288fead484f6755ad0815fc74c3742663761 /drivers/iommu/io-pgtable-arm.h
downloadlinux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.tar.gz
linux-stable-6668ed271eaefaa63e686bdfbedaeb7b8e492722.zip
selftests/bpf: Reject graph kptr use after RCU unlockgrafted
Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'drivers/iommu/io-pgtable-arm.h')
-rw-r--r--drivers/iommu/io-pgtable-arm.h30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/iommu/io-pgtable-arm.h b/drivers/iommu/io-pgtable-arm.h
new file mode 100644
index 000000000..ba7cfdf7a
--- /dev/null
+++ b/drivers/iommu/io-pgtable-arm.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef IO_PGTABLE_ARM_H_
+#define IO_PGTABLE_ARM_H_
+
+#define ARM_LPAE_TCR_TG0_4K 0
+#define ARM_LPAE_TCR_TG0_64K 1
+#define ARM_LPAE_TCR_TG0_16K 2
+
+#define ARM_LPAE_TCR_TG1_16K 1
+#define ARM_LPAE_TCR_TG1_4K 2
+#define ARM_LPAE_TCR_TG1_64K 3
+
+#define ARM_LPAE_TCR_SH_NS 0
+#define ARM_LPAE_TCR_SH_OS 2
+#define ARM_LPAE_TCR_SH_IS 3
+
+#define ARM_LPAE_TCR_RGN_NC 0
+#define ARM_LPAE_TCR_RGN_WBWA 1
+#define ARM_LPAE_TCR_RGN_WT 2
+#define ARM_LPAE_TCR_RGN_WB 3
+
+#define ARM_LPAE_TCR_PS_32_BIT 0x0ULL
+#define ARM_LPAE_TCR_PS_36_BIT 0x1ULL
+#define ARM_LPAE_TCR_PS_40_BIT 0x2ULL
+#define ARM_LPAE_TCR_PS_42_BIT 0x3ULL
+#define ARM_LPAE_TCR_PS_44_BIT 0x4ULL
+#define ARM_LPAE_TCR_PS_48_BIT 0x5ULL
+#define ARM_LPAE_TCR_PS_52_BIT 0x6ULL
+
+#endif /* IO_PGTABLE_ARM_H_ */