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| author | Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2026-09-04 10:43:19 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 07:58:36 -0700 |
| commit | 6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch) | |
| tree | 58e8288fead484f6755ad0815fc74c3742663761 /arch/x86/um/Kconfig | |
| download | linux-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 'arch/x86/um/Kconfig')
| -rw-r--r-- | arch/x86/um/Kconfig | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/x86/um/Kconfig b/arch/x86/um/Kconfig new file mode 100644 index 000000000..44b12e45f --- /dev/null +++ b/arch/x86/um/Kconfig @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: GPL-2.0 + +menu "Host processor type and features" + +source "arch/x86/Kconfig.cpu" + +endmenu + +config UML_X86 + def_bool y + select ARCH_USE_QUEUED_RWLOCKS + select ARCH_SUPPORTS_ATOMIC_RMW + select ARCH_USE_QUEUED_SPINLOCKS + select DCACHE_WORD_ACCESS + select HAVE_EFFICIENT_UNALIGNED_ACCESS + select UML_SUBARCH_SUPPORTS_SMP if X86_CX8 + +config 64BIT + bool "64-bit kernel" if "$(SUBARCH)" = "x86" + default "$(SUBARCH)" != "i386" + +config X86_32 + def_bool !64BIT + select ARCH_32BIT_OFF_T + select ARCH_WANT_IPC_PARSE_VERSION + select MODULES_USE_ELF_REL + select CLONE_BACKWARDS + select OLD_SIGSUSPEND3 + select OLD_SIGACTION + +config X86_64 + def_bool 64BIT + select MODULES_USE_ELF_RELA + +config ARCH_HAS_SC_SIGNALS + def_bool !64BIT + +config GENERIC_HWEIGHT + def_bool y |