From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- scripts/Makefile.compiler | 93 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 scripts/Makefile.compiler (limited to 'scripts/Makefile.compiler') diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler new file mode 100644 index 000000000..06bbe29c8 --- /dev/null +++ b/scripts/Makefile.compiler @@ -0,0 +1,93 @@ +# SPDX-License-Identifier: GPL-2.0-only + +# cc-cross-prefix +# Usage: CROSS_COMPILE := $(call cc-cross-prefix, m68k-linux-gnu- m68k-linux-) +# Return first where a gcc is found in PATH. +# If no gcc found in PATH with listed prefixes return nothing +# +# Note: '2>/dev/null' is here to force Make to invoke a shell. Otherwise, it +# would try to directly execute the shell builtin 'command'. This workaround +# should be kept for a long time since this issue was fixed only after the +# GNU Make 4.2.1 release. +cc-cross-prefix = $(firstword $(foreach c, $(1), \ + $(if $(shell command -v -- $(c)gcc 2>/dev/null), $(c)))) + +# output directory for tests below +TMPOUT = .tmp_$$$$ + +# try-run +# Usage: option = $(call try-run, $(CC)...-o "$$TMP",option-ok,otherwise) +# Exit code chooses option. "$$TMP" serves as a temporary file and is +# automatically cleaned up. +try-run = $(shell set -e; \ + TMP=$(TMPOUT)/tmp; \ + trap "rm -rf $(TMPOUT)" EXIT; \ + mkdir -p $(TMPOUT); \ + if ($(1)) >/dev/null 2>&1; \ + then echo "$(2)"; \ + else echo "$(3)"; \ + fi) + +# as-option +# Usage: aflags-y += $(call as-option,-Wa$(comma)-isa=foo,) + +as-option = $(call try-run,\ + $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(1) -c -x assembler-with-cpp /dev/null -o "$$TMP",$(1),$(2)) + +# as-instr +# Usage: aflags-y += $(call as-instr,instr,option1,option2) + +as-instr = $(call try-run,\ + printf "%b\n" "$(1)" | $(CC) -Werror $(CLANG_FLAGS) $(KBUILD_AFLAGS) -Wa$(comma)--fatal-warnings -c -x assembler-with-cpp -o "$$TMP" -,$(2),$(3)) + +# __cc-option +# Usage: MY_CFLAGS += $(call __cc-option,$(CC),$(MY_CFLAGS),-march=winchip-c6,-march=i586) +__cc-option = $(call try-run,\ + $(1) -Werror $(2) $(3:-Wno-%=-W%) -c -x c /dev/null -o "$$TMP",$(3),$(4)) + +# cc-option +# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) + +cc-option = $(call __cc-option, $(CC),\ + $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS),$(1),$(2)) + +# cc-option-yn +# Usage: flag := $(call cc-option-yn,-march=winchip-c6) +cc-option-yn = $(if $(call cc-option,$1),y,n) + +# cc-disable-warning +# Usage: cflags-y += $(call cc-disable-warning,unused-but-set-variable) +cc-disable-warning = $(call cc-option,-Wno-$(strip $1)) + +# gcc-min-version +# Usage: cflags-$(call gcc-min-version, 110100) += -foo +gcc-min-version = $(call test-ge, $(CONFIG_GCC_VERSION), $1) + +# clang-min-version +# Usage: cflags-$(call clang-min-version, 110000) += -foo +clang-min-version = $(call test-ge, $(CONFIG_CLANG_VERSION), $1) + +# rustc-min-version +# Usage: rustc-$(call rustc-min-version, 108500) += -Cfoo +rustc-min-version = $(call test-ge, $(CONFIG_RUSTC_VERSION), $1) + +# ld-option +# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y) +ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3)) + +# __rustc-option +# Usage: MY_RUSTFLAGS += $(call __rustc-option,$(RUSTC),$(MY_RUSTFLAGS),-Cinstrument-coverage,-Zinstrument-coverage) +# TODO: remove RUSTC_BOOTSTRAP=1 when we raise the minimum GNU Make version to 4.4 +__rustc-option = $(call try-run,\ + echo '$(pound)![allow(missing_docs)]$(pound)![feature(no_core)]$(pound)![no_core]' | RUSTC_BOOTSTRAP=1\ + $(1) --sysroot=/dev/null $(KBUILD_RUSTFLAGS_OPTION_CHKS) $(filter-out --sysroot=/dev/null --target=%target.json,$(2)) $(3)\ + --crate-type=rlib --out-dir=$(TMPOUT) --emit=obj=- - >/dev/null,$(3),$(4)) + +# rustc-option +# Usage: rustflags-y += $(call rustc-option,-Cinstrument-coverage,-Zinstrument-coverage) +rustc-option = $(call __rustc-option, $(RUSTC),\ + $(KBUILD_RUSTFLAGS),$(1),$(2)) + +# rustc-option-yn +# Usage: flag := $(call rustc-option-yn,-Cinstrument-coverage) +rustc-option-yn = $(if $(call rustc-option,$1),y,n) -- cgit v1.3.1