From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock 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 Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- arch/arm/nwfpe/fpopcode.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 arch/arm/nwfpe/fpopcode.c (limited to 'arch/arm/nwfpe/fpopcode.c') diff --git a/arch/arm/nwfpe/fpopcode.c b/arch/arm/nwfpe/fpopcode.c new file mode 100644 index 000000000..c680bf1bb --- /dev/null +++ b/arch/arm/nwfpe/fpopcode.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + NetWinder Floating Point Emulator + (c) Rebel.COM, 1998,1999 + + Direct questions, comments to Scott Bambrough + +*/ + +#include "fpa11.h" +#include "softfloat.h" +#include "fpopcode.h" +#include "fpsr.h" +#include "fpmodule.h" +#include "fpmodule.inl" + +#ifdef CONFIG_FPE_NWFPE_XP +const floatx80 floatx80Constant[] = { + { .high = 0x0000, .low = 0x0000000000000000ULL},/* extended 0.0 */ + { .high = 0x3fff, .low = 0x8000000000000000ULL},/* extended 1.0 */ + { .high = 0x4000, .low = 0x8000000000000000ULL},/* extended 2.0 */ + { .high = 0x4000, .low = 0xc000000000000000ULL},/* extended 3.0 */ + { .high = 0x4001, .low = 0x8000000000000000ULL},/* extended 4.0 */ + { .high = 0x4001, .low = 0xa000000000000000ULL},/* extended 5.0 */ + { .high = 0x3ffe, .low = 0x8000000000000000ULL},/* extended 0.5 */ + { .high = 0x4002, .low = 0xa000000000000000ULL},/* extended 10.0 */ +}; +#endif + +const float64 float64Constant[] = { + 0x0000000000000000ULL, /* double 0.0 */ + 0x3ff0000000000000ULL, /* double 1.0 */ + 0x4000000000000000ULL, /* double 2.0 */ + 0x4008000000000000ULL, /* double 3.0 */ + 0x4010000000000000ULL, /* double 4.0 */ + 0x4014000000000000ULL, /* double 5.0 */ + 0x3fe0000000000000ULL, /* double 0.5 */ + 0x4024000000000000ULL /* double 10.0 */ +}; + +const float32 float32Constant[] = { + 0x00000000, /* single 0.0 */ + 0x3f800000, /* single 1.0 */ + 0x40000000, /* single 2.0 */ + 0x40400000, /* single 3.0 */ + 0x40800000, /* single 4.0 */ + 0x40a00000, /* single 5.0 */ + 0x3f000000, /* single 0.5 */ + 0x41200000 /* single 10.0 */ +}; + -- cgit v1.3.1