selftests/bpf: Check that JMP32 pointer vs zero jumps are not predictedgrafted

Add jmp32_ptr_vs_zero_jne: the fall-through of the 32-bit compare, which
the verifier used to skip, contains an out of bounds map value access,
hence w/o the previous patch the program is accepted. See previous patch
for detailed description.

Reported-by: Nicholas Carlini <npc@anthropic.com>
Suggested-by: Nicholas Carlini <npc@anthropic.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260904083325.2083493-6-eddyz87@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 45 insertions, 0 deletions

diff --git a/scripts/Makefile.vdsoinst b/scripts/Makefile.vdsoinst
new file mode 100644
index 000000000..d9f724321
--- /dev/null
+++ b/scripts/Makefile.vdsoinst
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# ==========================================================================
+# Install unstripped copies of vDSO
+# ==========================================================================
+
+PHONY := __default
+__default:
+	@:
+
+include $(srctree)/scripts/Kbuild.include
+
+install-dir := $(MODLIB)/vdso
+
+define gen_install_rules
+
+dest := $(install-dir)/$$(patsubst %.dbg,%,$$(notdir $(1)))
+
+__default: $$(dest)
+$$(dest): $(1) FORCE
+	$$(call cmd,install)
+
+build-id-file := $$(shell $(READELF) -n $(1) 2>/dev/null | sed -n 's@^.*Build ID: \(..\)\(.*\)@\1/\2@p')
+
+ifneq ($$(build-id-file),)
+link := $(install-dir)/.build-id/$$(build-id-file).debug
+
+__default: $$(link)
+$$(link): $$(dest) FORCE
+	$$(call cmd,symlink)
+endif
+
+endef
+
+$(foreach x, $(sort $(INSTALL_FILES)), $(eval $(call gen_install_rules,$(x))))
+
+quiet_cmd_install = INSTALL $@
+      cmd_install = mkdir -p $(dir $@); cp $< $@
+
+quiet_cmd_symlink = SYMLINK $@
+      cmd_symlink = mkdir -p $(dir $@); ln -sf --relative $< $@
+
+PHONY += FORCE
+FORCE:
+
+.PHONY: $(PHONY)