diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 62f6bced3a3c48..afca36f53c4927 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -136,21 +136,29 @@ static struct bpf_map *find_and_alloc_map(union bpf_attr *attr) void *bpf_map_area_alloc(size_t size, int numa_node) { - /* We definitely need __GFP_NORETRY, so OOM killer doesn't - * trigger under memory pressure as we really just want to - * fail instead. + /* We really just want to fail instead of triggering OOM killer + * under memory pressure, therefore we set __GFP_NORETRY to kmalloc, + * which is used for lower order allocation requests. + * + * It has been observed that higher order allocation requests done by + * vmalloc with __GFP_NORETRY being set might fail due to not trying + * to reclaim memory from the page cache, thus we set + * __GFP_RETRY_MAYFAIL to avoid such situations. */ - const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO; + + const gfp_t flags = __GFP_NOWARN | __GFP_ZERO; void *area; if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { - area = kmalloc_node(size, GFP_USER | flags, numa_node); + area = kmalloc_node(size, GFP_USER | __GFP_NORETRY | flags, + numa_node); if (area != NULL) return area; } - return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags, - __builtin_return_address(0)); + return __vmalloc_node_flags_caller(size, numa_node, + GFP_KERNEL | __GFP_RETRY_MAYFAIL | + flags, __builtin_return_address(0)); } void bpf_map_area_free(void *area) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 86f9cd5d1c4e1a..fd502c1f71eb00 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -352,6 +352,14 @@ static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg) map_value_has_spin_lock(reg->map_ptr); } +static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type) +{ + return type == PTR_TO_SOCKET || + type == PTR_TO_SOCKET_OR_NULL || + type == PTR_TO_TCP_SOCK || + type == PTR_TO_TCP_SOCK_OR_NULL; +} + static bool arg_type_may_be_refcounted(enum bpf_arg_type type) { return type == ARG_PTR_TO_SOCK_COMMON; @@ -451,8 +459,9 @@ static void print_verifier_state(struct bpf_verifier_env *env, if (t == PTR_TO_STACK) verbose(env, ",call_%d", func(env, reg)->callsite); } else { - verbose(env, "(id=%d ref_obj_id=%d", reg->id, - reg->ref_obj_id); + verbose(env, "(id=%d", reg->id); + if (reg_type_may_be_refcounted_or_null(t)) + verbose(env, ",ref_obj_id=%d", reg->ref_obj_id); if (t != SCALAR_VALUE) verbose(env, ",off=%d", reg->off); if (type_is_pkt_pointer(t)) @@ -3372,7 +3381,7 @@ static int sanitize_ptr_alu(struct bpf_verifier_env *env, *dst_reg = *ptr_reg; } ret = push_stack(env, env->insn_idx + 1, env->insn_idx, true); - if (!ptr_is_dst_reg) + if (!ptr_is_dst_reg && ret) *dst_reg = tmp; return !ret ? -EFAULT : 0; } @@ -6069,15 +6078,17 @@ static int propagate_liveness(struct bpf_verifier_env *env, } /* Propagate read liveness of registers... */ BUILD_BUG_ON(BPF_REG_FP + 1 != MAX_BPF_REG); - /* We don't need to worry about FP liveness because it's read-only */ - for (i = 0; i < BPF_REG_FP; i++) { - if (vparent->frame[vparent->curframe]->regs[i].live & REG_LIVE_READ) - continue; - if (vstate->frame[vstate->curframe]->regs[i].live & REG_LIVE_READ) { - err = mark_reg_read(env, &vstate->frame[vstate->curframe]->regs[i], - &vparent->frame[vstate->curframe]->regs[i]); - if (err) - return err; + for (frame = 0; frame <= vstate->curframe; frame++) { + /* We don't need to worry about FP liveness, it's read-only */ + for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) { + if (vparent->frame[frame]->regs[i].live & REG_LIVE_READ) + continue; + if (vstate->frame[frame]->regs[i].live & REG_LIVE_READ) { + err = mark_reg_read(env, &vstate->frame[frame]->regs[i], + &vparent->frame[frame]->regs[i]); + if (err) + return err; + } } } diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index 61aaacf0cfa153..5bf8e52c41fcaf 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -3,7 +3,7 @@ BPF_VERSION = 0 BPF_PATCHLEVEL = 0 -BPF_EXTRAVERSION = 1 +BPF_EXTRAVERSION = 2 MAKEFLAGS += --no-print-directory @@ -79,8 +79,6 @@ export prefix libdir src obj libdir_SQ = $(subst ','\'',$(libdir)) libdir_relative_SQ = $(subst ','\'',$(libdir_relative)) -LIB_FILE = libbpf.a libbpf.so - VERSION = $(BPF_VERSION) PATCHLEVEL = $(BPF_PATCHLEVEL) EXTRAVERSION = $(BPF_EXTRAVERSION) @@ -88,7 +86,10 @@ EXTRAVERSION = $(BPF_EXTRAVERSION) OBJ = $@ N = -LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) +LIBBPF_VERSION = $(BPF_VERSION).$(BPF_PATCHLEVEL).$(BPF_EXTRAVERSION) + +LIB_TARGET = libbpf.a libbpf.so.$(LIBBPF_VERSION) +LIB_FILE = libbpf.a libbpf.so* # Set compile option CFLAGS ifdef EXTRA_CFLAGS @@ -128,16 +129,18 @@ all: export srctree OUTPUT CC LD CFLAGS V include $(srctree)/tools/build/Makefile.include -BPF_IN := $(OUTPUT)libbpf-in.o -LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) -VERSION_SCRIPT := libbpf.map +BPF_IN := $(OUTPUT)libbpf-in.o +VERSION_SCRIPT := libbpf.map + +LIB_TARGET := $(addprefix $(OUTPUT),$(LIB_TARGET)) +LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE)) GLOBAL_SYM_COUNT = $(shell readelf -s --wide $(BPF_IN) | \ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {s++} END{print s}') VERSIONED_SYM_COUNT = $(shell readelf -s --wide $(OUTPUT)libbpf.so | \ grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u | wc -l) -CMD_TARGETS = $(LIB_FILE) +CMD_TARGETS = $(LIB_TARGET) CXX_TEST_TARGET = $(OUTPUT)test_libbpf @@ -170,9 +173,13 @@ $(BPF_IN): force elfdep bpfdep echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true $(Q)$(MAKE) $(build)=libbpf -$(OUTPUT)libbpf.so: $(BPF_IN) - $(QUIET_LINK)$(CC) --shared -Wl,--version-script=$(VERSION_SCRIPT) \ - $^ -o $@ +$(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION) + +$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN) + $(QUIET_LINK)$(CC) --shared -Wl,-soname,libbpf.so.$(VERSION) \ + -Wl,--version-script=$(VERSION_SCRIPT) $^ -o $@ + @ln -sf $(@F) $(OUTPUT)libbpf.so + @ln -sf $(@F) $(OUTPUT)libbpf.so.$(VERSION) $(OUTPUT)libbpf.a: $(BPF_IN) $(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^ @@ -192,6 +199,12 @@ check_abi: $(OUTPUT)libbpf.so exit 1; \ fi +define do_install_mkdir + if [ ! -d '$(DESTDIR_SQ)$1' ]; then \ + $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1'; \ + fi +endef + define do_install if [ ! -d '$(DESTDIR_SQ)$2' ]; then \ $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$2'; \ @@ -200,8 +213,9 @@ define do_install endef install_lib: all_cmd - $(call QUIET_INSTALL, $(LIB_FILE)) \ - $(call do_install,$(LIB_FILE),$(libdir_SQ)) + $(call QUIET_INSTALL, $(LIB_TARGET)) \ + $(call do_install_mkdir,$(libdir_SQ)); \ + cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ) install_headers: $(call QUIET_INSTALL, headers) \ @@ -219,7 +233,7 @@ config-clean: clean: $(call QUIET_CLEAN, libbpf) $(RM) $(TARGETS) $(CXX_TEST_TARGET) \ - *.o *~ *.a *.so .*.d .*.cmd LIBBPF-CFLAGS + *.o *~ *.a *.so *.so.$(VERSION) .*.d .*.cmd LIBBPF-CFLAGS $(call QUIET_CLEAN, core-gen) $(RM) $(OUTPUT)FEATURE-DUMP.libbpf diff --git a/tools/lib/bpf/README.rst b/tools/lib/bpf/README.rst index 5788479384cad1..cef7b77eab6950 100644 --- a/tools/lib/bpf/README.rst +++ b/tools/lib/bpf/README.rst @@ -111,6 +111,7 @@ starting from ``0.0.1``. Every time ABI is being changed, e.g. because a new symbol is added or semantic of existing symbol is changed, ABI version should be bumped. +This bump in ABI version is at most once per kernel development cycle. For example, if current state of ``libbpf.map`` is: diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index 4004891afa9c3d..f2ccae39ee66b3 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -1940,3 +1940,28 @@ .errstr = "!read_ok", .result = REJECT, }, +{ + "calls: cross frame pruning - liveness propagation", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32), + BPF_MOV64_IMM(BPF_REG_8, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_MOV64_IMM(BPF_REG_8, 1), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_prandom_u32), + BPF_MOV64_IMM(BPF_REG_9, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_MOV64_IMM(BPF_REG_9, 1), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 4), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_8, 1, 1), + BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SOCKET_FILTER, + .errstr_unpriv = "function calls to other bpf functions are allowed for root only", + .errstr = "!read_ok", + .result = REJECT, +},