diff mbox series

[bpf-next,v2,2/4] selftests/bpf: utility function to get program disassembly after jit

Message ID 20240815205449.242556-3-eddyz87@gmail.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series __jited_x86 test tag to check x86 assembly after jit | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Unittests
bpf/vmtest-bpf-next-VM_Test-0 success Logs for Lint
bpf/vmtest-bpf-next-VM_Test-3 success Logs for Validate matrix.py
bpf/vmtest-bpf-next-VM_Test-4 success Logs for aarch64-gcc / build / build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-5 success Logs for aarch64-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-10 success Logs for aarch64-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-12 success Logs for s390x-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-8 success Logs for aarch64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for aarch64-gcc / test (test_verifier, false, 360) / test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-6 success Logs for aarch64-gcc / test (test_maps, false, 360) / test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-7 success Logs for aarch64-gcc / test (test_progs, false, 360) / test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for s390x-gcc / build / build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-15 success Logs for s390x-gcc / test (test_verifier, false, 360) / test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-16 success Logs for s390x-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-18 success Logs for x86_64-gcc / build / build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-19 success Logs for x86_64-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-20 success Logs for x86_64-gcc / test (test_maps, false, 360) / test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-24 success Logs for x86_64-gcc / test (test_progs_parallel, true, 30) / test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for x86_64-gcc / veristat / veristat on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-25 success Logs for x86_64-gcc / test (test_verifier, false, 360) / test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-27 success Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-28 success Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17-O2
bpf/vmtest-bpf-next-VM_Test-29 success Logs for x86_64-llvm-17 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-30 success Logs for x86_64-llvm-17 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-32 success Logs for x86_64-llvm-17 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-31 success Logs for x86_64-llvm-17 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-33 success Logs for x86_64-llvm-17 / veristat
bpf/vmtest-bpf-next-VM_Test-34 success Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-35 success Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18-O2
bpf/vmtest-bpf-next-VM_Test-37 success Logs for x86_64-llvm-18 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-36 success Logs for x86_64-llvm-18 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-38 success Logs for x86_64-llvm-18 / test (test_progs_cpuv4, false, 360) / test_progs_cpuv4 on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-39 success Logs for x86_64-llvm-18 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-40 success Logs for x86_64-llvm-18 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-41 success Logs for x86_64-llvm-18 / veristat
bpf/vmtest-bpf-next-VM_Test-23 success Logs for x86_64-gcc / test (test_progs_no_alu32_parallel, true, 30) / test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-21 success Logs for x86_64-gcc / test (test_progs, false, 360) / test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-22 success Logs for x86_64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-13 success Logs for s390x-gcc / test (test_progs, false, 360) / test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for s390x-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on s390x with gcc
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 42 this patch: 42
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers warning 14 maintainers not CCed: mykolal@fb.com sdf@fomichev.me llvm@lists.linux.dev haoluo@google.com shuah@kernel.org jolsa@kernel.org ndesaulniers@google.com nathan@kernel.org linux-kselftest@vger.kernel.org justinstitt@google.com song@kernel.org morbo@google.com kpsingh@kernel.org john.fastabend@gmail.com
netdev/build_clang success Errors and warnings before: 44 this patch: 44
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 49 this patch: 49
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? WARNING: line length of 83 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 94 exceeds 80 columns WARNING: line length of 98 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Eduard Zingerman Aug. 15, 2024, 8:54 p.m. UTC 
This commit adds a utility function to get disassembled text for jited
representation of a BPF program designated by file descriptor.
Function prototype looks as follows:

    int get_jited_program_text(int fd, char *text, size_t text_sz)

Where 'fd' is a file descriptor for the program, 'text' and 'text_sz'
refer to a destination buffer for disassembled text.

The code and makefile changes are inspired by jit_disasm.c from bpftool.
Use llvm libraries to disassemble BPF program instead of libbfd to avoid
issues with disassembly output stability pointed out in [1].

Selftests makefile uses Makefile.feature to detect if LLVM libraries
are available. If that is not the case selftests build proceeds but
the function returns -ENOTSUP at runtime.

[1] commit eb9d1acf634b ("bpftool: Add LLVM as default library for disassembling JIT-ed programs")

Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
---
 tools/testing/selftests/bpf/.gitignore        |   1 +
 tools/testing/selftests/bpf/Makefile          |  51 +++-
 .../selftests/bpf/jit_disasm_helpers.c        | 234 ++++++++++++++++++
 .../selftests/bpf/jit_disasm_helpers.h        |  10 +
 4 files changed, 294 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/jit_disasm_helpers.c
 create mode 100644 tools/testing/selftests/bpf/jit_disasm_helpers.h

Comments

Andrii Nakryiko Aug. 15, 2024, 9:17 p.m. UTC | #1 
On Thu, Aug 15, 2024 at 1:56 PM Eduard Zingerman <eddyz87@gmail.com> wrote:
>
> This commit adds a utility function to get disassembled text for jited
> representation of a BPF program designated by file descriptor.
> Function prototype looks as follows:
>
>     int get_jited_program_text(int fd, char *text, size_t text_sz)
>
> Where 'fd' is a file descriptor for the program, 'text' and 'text_sz'
> refer to a destination buffer for disassembled text.
>
> The code and makefile changes are inspired by jit_disasm.c from bpftool.
> Use llvm libraries to disassemble BPF program instead of libbfd to avoid
> issues with disassembly output stability pointed out in [1].
>
> Selftests makefile uses Makefile.feature to detect if LLVM libraries
> are available. If that is not the case selftests build proceeds but
> the function returns -ENOTSUP at runtime.
>
> [1] commit eb9d1acf634b ("bpftool: Add LLVM as default library for disassembling JIT-ed programs")
>
> Acked-by: Yonghong Song <yonghong.song@linux.dev>
> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
> ---
>  tools/testing/selftests/bpf/.gitignore        |   1 +
>  tools/testing/selftests/bpf/Makefile          |  51 +++-
>  .../selftests/bpf/jit_disasm_helpers.c        | 234 ++++++++++++++++++
>  .../selftests/bpf/jit_disasm_helpers.h        |  10 +
>  4 files changed, 294 insertions(+), 2 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/jit_disasm_helpers.c
>  create mode 100644 tools/testing/selftests/bpf/jit_disasm_helpers.h
>
> diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
> index 8f14d8faeb0b..7de4108771a0 100644
> --- a/tools/testing/selftests/bpf/.gitignore
> +++ b/tools/testing/selftests/bpf/.gitignore
> @@ -8,6 +8,7 @@ test_lru_map
>  test_lpm_map
>  test_tag
>  FEATURE-DUMP.libbpf
> +FEATURE-DUMP.selftests
>  fixdep
>  /test_progs
>  /test_progs-no_alu32
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index f54185e96a95..b1a52739d9e7 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -33,6 +33,13 @@ OPT_FLAGS    ?= $(if $(RELEASE),-O2,-O0)
>  LIBELF_CFLAGS  := $(shell $(PKG_CONFIG) libelf --cflags 2>/dev/null)
>  LIBELF_LIBS    := $(shell $(PKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
>
> +ifeq ($(srctree),)
> +srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> +srctree := $(patsubst %/,%,$(dir $(srctree)))
> +srctree := $(patsubst %/,%,$(dir $(srctree)))
> +srctree := $(patsubst %/,%,$(dir $(srctree)))
> +endif
> +
>  CFLAGS += -g $(OPT_FLAGS) -rdynamic                                    \
>           -Wall -Werror -fno-omit-frame-pointer                         \
>           $(GENFLAGS) $(SAN_CFLAGS) $(LIBELF_CFLAGS)                    \
> @@ -55,6 +62,11 @@ progs/test_sk_lookup.c-CFLAGS := -fno-strict-aliasing
>  progs/timer_crash.c-CFLAGS := -fno-strict-aliasing
>  progs/test_global_func9.c-CFLAGS := -fno-strict-aliasing
>
> +# Some utility functions use LLVM libraries
> +jit_disasm_helpers.c-CFLAGS = $(LLVM_CFLAGS)
> +test_progs-LDLIBS = $(LLVM_LDLIBS)
> +test_progs-LDFLAGS = $(LLVM_LDFLAGS)
> +
>  ifneq ($(LLVM),)
>  # Silence some warnings when compiled with clang
>  CFLAGS += -Wno-unused-command-line-argument
> @@ -164,6 +176,31 @@ endef
>
>  include ../lib.mk
>
> +NON_CHECK_FEAT_TARGETS := clean docs-clean
> +CHECK_FEAT := $(filter-out $(NON_CHECK_FEAT_TARGETS),$(or $(MAKECMDGOALS), "none"))
> +ifneq ($(CHECK_FEAT),)
> +FEATURE_USER := .selftests
> +FEATURE_TESTS := llvm
> +FEATURE_DISPLAY := $(FEATURE_TESTS)
> +
> +# Makefile.feature expects OUTPUT to end with a slash
> +$(let OUTPUT,$(OUTPUT)/,\
> +       $(eval include ../../../build/Makefile.feature))
> +endif
> +
> +ifeq ($(feature-llvm),1)
> +  LLVM_CFLAGS  += -DHAVE_LLVM_SUPPORT
> +  LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
> +  # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict
> +  LLVM_CFLAGS  += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags))
> +  LLVM_LDLIBS  += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
> +  ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
> +    LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))
> +    LLVM_LDLIBS += -lstdc++
> +  endif
> +  LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
> +endif
> +

Seems like we raced between me commenting on v1 and you posting v2 :(

But I just noticed that formatting seems off here. Can you please
check space vs tabs issues?

>  SCRATCH_DIR := $(OUTPUT)/tools
>  BUILD_DIR := $(SCRATCH_DIR)/build
>  INCLUDE_DIR := $(SCRATCH_DIR)/include
> @@ -488,6 +525,7 @@ define DEFINE_TEST_RUNNER
>
>  TRUNNER_OUTPUT := $(OUTPUT)$(if $2,/)$2
>  TRUNNER_BINARY := $1$(if $2,-)$2
> +TRUNNER_BASE_NAME := $1

[...]
Eduard Zingerman Aug. 15, 2024, 9:54 p.m. UTC | #2 
On Thu, 2024-08-15 at 14:17 -0700, Andrii Nakryiko wrote:

[...]

> > @@ -164,6 +176,31 @@ endef
> > 
> >  include ../lib.mk
> > 
> > +NON_CHECK_FEAT_TARGETS := clean docs-clean
> > +CHECK_FEAT := $(filter-out $(NON_CHECK_FEAT_TARGETS),$(or $(MAKECMDGOALS), "none"))
> > +ifneq ($(CHECK_FEAT),)
> > +FEATURE_USER := .selftests
> > +FEATURE_TESTS := llvm
> > +FEATURE_DISPLAY := $(FEATURE_TESTS)
> > +
> > +# Makefile.feature expects OUTPUT to end with a slash
> > +$(let OUTPUT,$(OUTPUT)/,\
> > +       $(eval include ../../../build/Makefile.feature))
> > +endif
> > +
> > +ifeq ($(feature-llvm),1)
> > +  LLVM_CFLAGS  += -DHAVE_LLVM_SUPPORT
> > +  LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
> > +  # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict
> > +  LLVM_CFLAGS  += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags))
> > +  LLVM_LDLIBS  += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
> > +  ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
> > +    LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))
> > +    LLVM_LDLIBS += -lstdc++
> > +  endif
> > +  LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
> > +endif
> > +
> 
> Seems like we raced between me commenting on v1 and you posting v2 :(

Yes, I should have waited a bit more, sorry.

> But I just noticed that formatting seems off here. Can you please
> check space vs tabs issues?

For the block above the lines are indented using two spaces and four spaces.
This is not a rule body, so should not be a problem afaik.
What's not working on your side?

> >  SCRATCH_DIR := $(OUTPUT)/tools
> >  BUILD_DIR := $(SCRATCH_DIR)/build
> >  INCLUDE_DIR := $(SCRATCH_DIR)/include

[...]
Andrii Nakryiko Aug. 15, 2024, 10:10 p.m. UTC | #3 
On Thu, Aug 15, 2024 at 2:54 PM Eduard Zingerman <eddyz87@gmail.com> wrote:
>
> On Thu, 2024-08-15 at 14:17 -0700, Andrii Nakryiko wrote:
>
> [...]
>
> > > @@ -164,6 +176,31 @@ endef
> > >
> > >  include ../lib.mk
> > >
> > > +NON_CHECK_FEAT_TARGETS := clean docs-clean
> > > +CHECK_FEAT := $(filter-out $(NON_CHECK_FEAT_TARGETS),$(or $(MAKECMDGOALS), "none"))
> > > +ifneq ($(CHECK_FEAT),)
> > > +FEATURE_USER := .selftests
> > > +FEATURE_TESTS := llvm
> > > +FEATURE_DISPLAY := $(FEATURE_TESTS)
> > > +
> > > +# Makefile.feature expects OUTPUT to end with a slash
> > > +$(let OUTPUT,$(OUTPUT)/,\
> > > +       $(eval include ../../../build/Makefile.feature))
> > > +endif
> > > +
> > > +ifeq ($(feature-llvm),1)
> > > +  LLVM_CFLAGS  += -DHAVE_LLVM_SUPPORT
> > > +  LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
> > > +  # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict
> > > +  LLVM_CFLAGS  += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags))
> > > +  LLVM_LDLIBS  += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
> > > +  ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
> > > +    LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))
> > > +    LLVM_LDLIBS += -lstdc++
> > > +  endif
> > > +  LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
> > > +endif
> > > +
> >
> > Seems like we raced between me commenting on v1 and you posting v2 :(
>
> Yes, I should have waited a bit more, sorry.
>

no worries

> > But I just noticed that formatting seems off here. Can you please
> > check space vs tabs issues?
>
> For the block above the lines are indented using two spaces and four spaces.
> This is not a rule body, so should not be a problem afaik.
> What's not working on your side?
>

oh, it's just for consistency with the rest of Makefile. We use tabs
for indentation, so let's stay consistent.

> > >  SCRATCH_DIR := $(OUTPUT)/tools
> > >  BUILD_DIR := $(SCRATCH_DIR)/build
> > >  INCLUDE_DIR := $(SCRATCH_DIR)/include
>
> [...]
>
Eduard Zingerman Aug. 15, 2024, 10:13 p.m. UTC | #4 
On Thu, 2024-08-15 at 15:10 -0700, Andrii Nakryiko wrote:

[...]

> > For the block above the lines are indented using two spaces and four spaces.
> > This is not a rule body, so should not be a problem afaik.
> > What's not working on your side?
> > 
> 
> oh, it's just for consistency with the rest of Makefile. We use tabs
> for indentation, so let's stay consistent.

Ok, will change

[...]
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 8f14d8faeb0b..7de4108771a0 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -8,6 +8,7 @@  test_lru_map
 test_lpm_map
 test_tag
 FEATURE-DUMP.libbpf
+FEATURE-DUMP.selftests
 fixdep
 /test_progs
 /test_progs-no_alu32
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index f54185e96a95..b1a52739d9e7 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -33,6 +33,13 @@  OPT_FLAGS	?= $(if $(RELEASE),-O2,-O0)
 LIBELF_CFLAGS	:= $(shell $(PKG_CONFIG) libelf --cflags 2>/dev/null)
 LIBELF_LIBS	:= $(shell $(PKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
 
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(CURDIR)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+endif
+
 CFLAGS += -g $(OPT_FLAGS) -rdynamic					\
 	  -Wall -Werror -fno-omit-frame-pointer				\
 	  $(GENFLAGS) $(SAN_CFLAGS) $(LIBELF_CFLAGS)			\
@@ -55,6 +62,11 @@  progs/test_sk_lookup.c-CFLAGS := -fno-strict-aliasing
 progs/timer_crash.c-CFLAGS := -fno-strict-aliasing
 progs/test_global_func9.c-CFLAGS := -fno-strict-aliasing
 
+# Some utility functions use LLVM libraries
+jit_disasm_helpers.c-CFLAGS = $(LLVM_CFLAGS)
+test_progs-LDLIBS = $(LLVM_LDLIBS)
+test_progs-LDFLAGS = $(LLVM_LDFLAGS)
+
 ifneq ($(LLVM),)
 # Silence some warnings when compiled with clang
 CFLAGS += -Wno-unused-command-line-argument
@@ -164,6 +176,31 @@  endef
 
 include ../lib.mk
 
+NON_CHECK_FEAT_TARGETS := clean docs-clean
+CHECK_FEAT := $(filter-out $(NON_CHECK_FEAT_TARGETS),$(or $(MAKECMDGOALS), "none"))
+ifneq ($(CHECK_FEAT),)
+FEATURE_USER := .selftests
+FEATURE_TESTS := llvm
+FEATURE_DISPLAY := $(FEATURE_TESTS)
+
+# Makefile.feature expects OUTPUT to end with a slash
+$(let OUTPUT,$(OUTPUT)/,\
+	$(eval include ../../../build/Makefile.feature))
+endif
+
+ifeq ($(feature-llvm),1)
+  LLVM_CFLAGS  += -DHAVE_LLVM_SUPPORT
+  LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
+  # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict
+  LLVM_CFLAGS  += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags))
+  LLVM_LDLIBS  += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
+  ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
+    LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))
+    LLVM_LDLIBS += -lstdc++
+  endif
+  LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
+endif
+
 SCRATCH_DIR := $(OUTPUT)/tools
 BUILD_DIR := $(SCRATCH_DIR)/build
 INCLUDE_DIR := $(SCRATCH_DIR)/include
@@ -488,6 +525,7 @@  define DEFINE_TEST_RUNNER
 
 TRUNNER_OUTPUT := $(OUTPUT)$(if $2,/)$2
 TRUNNER_BINARY := $1$(if $2,-)$2
+TRUNNER_BASE_NAME := $1
 TRUNNER_TEST_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.test.o,	\
 				 $$(notdir $$(wildcard $(TRUNNER_TESTS_DIR)/*.c)))
 TRUNNER_EXTRA_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o,		\
@@ -611,6 +649,10 @@  ifeq ($(filter clean docs-clean,$(MAKECMDGOALS)),)
 include $(wildcard $(TRUNNER_TEST_OBJS:.o=.d))
 endif
 
+# add per extra obj CFGLAGS definitions
+$(foreach N,$(patsubst $(TRUNNER_OUTPUT)/%.o,%,$(TRUNNER_EXTRA_OBJS)),	\
+	$(eval $(TRUNNER_OUTPUT)/$(N).o: CFLAGS += $($(N).c-CFLAGS)))
+
 $(TRUNNER_EXTRA_OBJS): $(TRUNNER_OUTPUT)/%.o:				\
 		       %.c						\
 		       $(TRUNNER_EXTRA_HDRS)				\
@@ -627,6 +669,9 @@  ifneq ($2:$(OUTPUT),:$(shell pwd))
 	$(Q)rsync -aq $$^ $(TRUNNER_OUTPUT)/
 endif
 
+$(OUTPUT)/$(TRUNNER_BINARY): LDLIBS += $$($(TRUNNER_BASE_NAME)-LDLIBS)
+$(OUTPUT)/$(TRUNNER_BINARY): LDFLAGS += $$($(TRUNNER_BASE_NAME)-LDFLAGS)
+
 # some X.test.o files have runtime dependencies on Y.bpf.o files
 $(OUTPUT)/$(TRUNNER_BINARY): | $(TRUNNER_BPF_OBJS)
 
@@ -636,7 +681,7 @@  $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS)			\
 			     $(TRUNNER_BPFTOOL)				\
 			     | $(TRUNNER_BINARY)-extras
 	$$(call msg,BINARY,,$$@)
-	$(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@
+	$(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) $$(LDFLAGS) -o $$@
 	$(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@
 	$(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)bpftool \
 		   $(OUTPUT)/$(if $2,$2/)bpftool
@@ -655,6 +700,7 @@  TRUNNER_EXTRA_SOURCES := test_progs.c		\
 			 cap_helpers.c		\
 			 unpriv_helpers.c 	\
 			 netlink_helpers.c	\
+			 jit_disasm_helpers.c	\
 			 test_loader.c		\
 			 xsk.c			\
 			 disasm.c		\
@@ -797,7 +843,8 @@  EXTRA_CLEAN := $(SCRATCH_DIR) $(HOST_SCRATCH_DIR)			\
 	$(addprefix $(OUTPUT)/,*.o *.d *.skel.h *.lskel.h *.subskel.h	\
 			       no_alu32 cpuv4 bpf_gcc bpf_testmod.ko	\
 			       bpf_test_no_cfi.ko			\
-			       liburandom_read.so)
+			       liburandom_read.so)			\
+	$(OUTPUT)/FEATURE-DUMP.selftests
 
 .PHONY: docs docs-clean
 
diff --git a/tools/testing/selftests/bpf/jit_disasm_helpers.c b/tools/testing/selftests/bpf/jit_disasm_helpers.c
new file mode 100644
index 000000000000..d1ded19be759
--- /dev/null
+++ b/tools/testing/selftests/bpf/jit_disasm_helpers.c
@@ -0,0 +1,234 @@ 
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <test_progs.h>
+
+#ifdef HAVE_LLVM_SUPPORT
+
+#include <llvm-c/Core.h>
+#include <llvm-c/Disassembler.h>
+#include <llvm-c/Target.h>
+#include <llvm-c/TargetMachine.h>
+
+/* The intent is to use get_jited_program_text() for small test
+ * programs written in BPF assembly, thus assume that 32 local labels
+ * would be sufficient.
+ */
+#define MAX_LOCAL_LABELS 32
+
+static bool llvm_initialized;
+
+struct local_labels {
+	bool print_phase;
+	__u32 prog_len;
+	__u32 cnt;
+	__u32 pcs[MAX_LOCAL_LABELS];
+	char names[MAX_LOCAL_LABELS][4];
+};
+
+static const char *lookup_symbol(void *data, uint64_t ref_value, uint64_t *ref_type,
+				 uint64_t ref_pc, const char **ref_name)
+{
+	struct local_labels *labels = data;
+	uint64_t type = *ref_type;
+	int i;
+
+	*ref_type = LLVMDisassembler_ReferenceType_InOut_None;
+	*ref_name = NULL;
+	if (type != LLVMDisassembler_ReferenceType_In_Branch)
+		return NULL;
+	/* Depending on labels->print_phase either discover local labels or
+	 * return a name assigned with local jump target:
+	 * - if print_phase is true and ref_value is in labels->pcs,
+	 *   return corresponding labels->name.
+	 * - if print_phase is false, save program-local jump targets
+	 *   in labels->pcs;
+	 */
+	if (labels->print_phase) {
+		for (i = 0; i < labels->cnt; ++i)
+			if (labels->pcs[i] == ref_value)
+				return labels->names[i];
+	} else {
+		if (labels->cnt < MAX_LOCAL_LABELS && ref_value < labels->prog_len)
+			labels->pcs[labels->cnt++] = ref_value;
+	}
+	return NULL;
+}
+
+static int disasm_insn(LLVMDisasmContextRef ctx, uint8_t *image, __u32 len, __u32 pc,
+		       char *buf, __u32 buf_sz)
+{
+	int i, cnt;
+
+	cnt = LLVMDisasmInstruction(ctx, image + pc, len - pc, pc,
+				    buf, buf_sz);
+	if (cnt > 0)
+		return cnt;
+	PRINT_FAIL("Can't disasm instruction at offset %d:", pc);
+	for (i = 0; i < 16 && pc + i < len; ++i)
+		printf(" %02x", image[pc + i]);
+	printf("\n");
+	return -EINVAL;
+}
+
+static int cmp_u32(const void *_a, const void *_b)
+{
+	__u32 a = *(__u32 *)_a;
+	__u32 b = *(__u32 *)_b;
+
+	if (a < b)
+		return -1;
+	if (a > b)
+		return 1;
+	return 0;
+}
+
+static int disasm_one_func(FILE *text_out, uint8_t *image, __u32 len)
+{
+	char *label, *colon, *triple = NULL;
+	LLVMDisasmContextRef ctx = NULL;
+	struct local_labels labels = {};
+	__u32 *label_pc, pc;
+	int i, cnt, err = 0;
+	char buf[64];
+
+	triple = LLVMGetDefaultTargetTriple();
+	ctx = LLVMCreateDisasm(triple, &labels, 0, NULL, lookup_symbol);
+	if (!ASSERT_OK_PTR(ctx, "LLVMCreateDisasm")) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	cnt = LLVMSetDisasmOptions(ctx, LLVMDisassembler_Option_PrintImmHex);
+	if (!ASSERT_EQ(cnt, 1, "LLVMSetDisasmOptions")) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* discover labels */
+	labels.prog_len = len;
+	pc = 0;
+	while (pc < len) {
+		cnt = disasm_insn(ctx, image, len, pc, buf, 1);
+		if (cnt < 0) {
+			err = cnt;
+			goto out;
+		}
+		pc += cnt;
+	}
+	qsort(labels.pcs, labels.cnt, sizeof(*labels.pcs), cmp_u32);
+	for (i = 0; i < labels.cnt; ++i)
+		/* use (i % 100) to avoid format truncation warning */
+		snprintf(labels.names[i], sizeof(labels.names[i]), "L%d", i % 100);
+
+	/* now print with labels */
+	labels.print_phase = true;
+	pc = 0;
+	while (pc < len) {
+		cnt = disasm_insn(ctx, image, len, pc, buf, sizeof(buf));
+		if (cnt < 0) {
+			err = cnt;
+			goto out;
+		}
+		label_pc = bsearch(&pc, labels.pcs, labels.cnt, sizeof(*labels.pcs), cmp_u32);
+		label = "";
+		colon = "";
+		if (label_pc) {
+			label = labels.names[label_pc - labels.pcs];
+			colon = ":";
+		}
+		fprintf(text_out, "%x:\t", pc);
+		for (i = 0; i < cnt; ++i)
+			fprintf(text_out, "%02x ", image[pc + i]);
+		for (i = cnt * 3; i < 12 * 3; ++i)
+			fputc(' ', text_out);
+		fprintf(text_out, "%s%s%s\n", label, colon, buf);
+		pc += cnt;
+	}
+
+out:
+	if (triple)
+		LLVMDisposeMessage(triple);
+	if (ctx)
+		LLVMDisasmDispose(ctx);
+	return err;
+}
+
+int get_jited_program_text(int fd, char *text, size_t text_sz)
+{
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	__u32 jited_funcs, len, pc;
+	__u32 *func_lens = NULL;
+	FILE *text_out = NULL;
+	uint8_t *image = NULL;
+	int i, err = 0;
+
+	if (!llvm_initialized) {
+		LLVMInitializeAllTargetInfos();
+		LLVMInitializeAllTargetMCs();
+		LLVMInitializeAllDisassemblers();
+		llvm_initialized = 1;
+	}
+
+	text_out = fmemopen(text, text_sz, "w");
+	if (!ASSERT_OK_PTR(text_out, "open_memstream")) {
+		err = -errno;
+		goto out;
+	}
+
+	/* first call is to find out jited program len */
+	err = bpf_prog_get_info_by_fd(fd, &info, &info_len);
+	if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd #1"))
+		goto out;
+
+	len = info.jited_prog_len;
+	image = malloc(len);
+	if (!ASSERT_OK_PTR(image, "malloc(info.jited_prog_len)")) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	jited_funcs = info.nr_jited_func_lens;
+	func_lens = malloc(jited_funcs * sizeof(__u32));
+	if (!ASSERT_OK_PTR(func_lens, "malloc(info.nr_jited_func_lens)")) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	memset(&info, 0, sizeof(info));
+	info.jited_prog_insns = (__u64)image;
+	info.jited_prog_len = len;
+	info.jited_func_lens = (__u64)func_lens;
+	info.nr_jited_func_lens = jited_funcs;
+	err = bpf_prog_get_info_by_fd(fd, &info, &info_len);
+	if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd #2"))
+		goto out;
+
+	for (pc = 0, i = 0; i < jited_funcs; ++i) {
+		fprintf(text_out, "func #%d:\n", i);
+		disasm_one_func(text_out, image + pc, func_lens[i]);
+		fprintf(text_out, "\n");
+		pc += func_lens[i];
+	}
+
+out:
+	if (text_out)
+		fclose(text_out);
+	if (image)
+		free(image);
+	if (func_lens)
+		free(func_lens);
+	return err;
+}
+
+#else /* HAVE_LLVM_SUPPORT */
+
+int get_jited_program_text(int fd, char *text, size_t text_sz)
+{
+	if (env.verbosity >= VERBOSE_VERY)
+		printf("compiled w/o llvm development libraries, can't dis-assembly binary code");
+	return -ENOTSUP;
+}
+
+#endif /* HAVE_LLVM_SUPPORT */
diff --git a/tools/testing/selftests/bpf/jit_disasm_helpers.h b/tools/testing/selftests/bpf/jit_disasm_helpers.h
new file mode 100644
index 000000000000..e6924fd65ecf
--- /dev/null
+++ b/tools/testing/selftests/bpf/jit_disasm_helpers.h
@@ -0,0 +1,10 @@ 
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+#ifndef __JIT_DISASM_HELPERS_H
+#define __JIT_DISASM_HELPERS_H
+
+#include <stddef.h>
+
+int get_jited_program_text(int fd, char *text, size_t text_sz);
+
+#endif /* __JIT_DISASM_HELPERS_H */