Commit b0691222 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'nolibc.2022.07.27a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu 

Pull nolibc updates from Paul McKenney:
 "This provides nolibc updates, perhaps most notably improved testing
  via the 'cd tools/include/nolibc; make headers' command. This should
  be considered a smoke test. More thorough testing is in the works"

* tag 'nolibc.2022.07.27a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  tools/nolibc: add a help target to list supported targets
  tools/nolibc: make the default target build the headers
  tools/nolibc: fix the makefile to also work as "make -C tools ..."
  tools/nolibc/stdio: Add format attribute to enable printf warnings
  tools/nolibc/stdlib: Support overflow checking for older compiler versions
parents 7d9d077c 4f8126f3

tools/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -78,6 +78,9 @@ bpf/%: FORCE 
libapi: FORCE

	$(call descend,lib/api)



nolibc: FORCE

	$(call descend,include/nolibc)



nolibc_%: FORCE

	$(call descend,include/nolibc,$(patsubst nolibc_%,%,$@))

tools/include/nolibc/Makefile

+35 −2
Original line number Diff line number Diff line
@@ -7,13 +7,46 @@ ifeq ($(srctree),) 
srctree := $(patsubst %/tools/include/,%,$(dir $(CURDIR)))

endif



# when run as make -C tools/ nolibc_<foo> the arch is not set

ifeq ($(ARCH),)

include $(srctree)/scripts/subarch.include

ARCH = $(SUBARCH)

endif



# OUTPUT is only set when run from the main makefile, otherwise

# it defaults to this nolibc directory.

OUTPUT ?= $(CURDIR)/



ifeq ($(V),1)

Q=

else

Q=@

endif



nolibc_arch := $(patsubst arm64,aarch64,$(ARCH))

arch_file := arch-$(nolibc_arch).h

all_files := ctype.h errno.h nolibc.h signal.h std.h stdio.h stdlib.h string.h \

             sys.h time.h types.h unistd.h



# install all headers needed to support a bare-metal compiler

all:

all: headers



install: help



help:

	@echo "Supported targets under nolibc:"

	@echo "  all                 call \"headers\""

	@echo "  clean               clean the sysroot"

	@echo "  headers             prepare a sysroot in tools/include/nolibc/sysroot"

	@echo "  headers_standalone  like \"headers\", and also install kernel headers"

	@echo "  help                this help"

	@echo ""

	@echo "These targets may also be called from tools as \"make nolibc_<target>\"."

	@echo ""

	@echo "Currently using the following variables:"

	@echo "  ARCH    = $(ARCH)"

	@echo "  OUTPUT  = $(OUTPUT)"

	@echo ""



# Note: when ARCH is "x86" we concatenate both x86_64 and i386

headers:
@@ -36,7 +69,7 @@ headers: 


headers_standalone: headers

	$(Q)$(MAKE) -C $(srctree) headers

	$(Q)$(MAKE) -C $(srctree) headers_install INSTALL_HDR_PATH=$(OUTPUT)/sysroot

	$(Q)$(MAKE) -C $(srctree) headers_install INSTALL_HDR_PATH=$(OUTPUT)sysroot



clean:

	$(call QUIET_CLEAN, nolibc) rm -rf "$(OUTPUT)sysroot"

tools/include/nolibc/stdio.h

+2 −2
Original line number Diff line number Diff line
@@ -273,7 +273,7 @@ int vfprintf(FILE *stream, const char *fmt, va_list args) 
	return written;

}



static __attribute__((unused))

static __attribute__((unused, format(printf, 2, 3)))

int fprintf(FILE *stream, const char *fmt, ...)

{

	va_list args;
@@ -285,7 +285,7 @@ int fprintf(FILE *stream, const char *fmt, ...) 
	return ret;

}



static __attribute__((unused))

static __attribute__((unused, format(printf, 1, 2)))

int printf(const char *fmt, ...)

{

	va_list args;

tools/include/nolibc/stdlib.h

+3 −4
Original line number Diff line number Diff line
@@ -128,10 +128,9 @@ void *malloc(size_t len) 
static __attribute__((unused))

void *calloc(size_t size, size_t nmemb)

{

	void *orig;

	size_t res = 0;

	size_t x = size * nmemb;



	if (__builtin_expect(__builtin_mul_overflow(nmemb, size, &res), 0)) {

	if (__builtin_expect(size && ((x / size) != nmemb), 0)) {

		SET_ERRNO(ENOMEM);

		return NULL;

	}
@@ -140,7 +139,7 @@ void *calloc(size_t size, size_t nmemb) 
	 * No need to zero the heap, the MAP_ANONYMOUS in malloc()

	 * already does it.

	 */

	return malloc(res);

	return malloc(x);

}



static __attribute__((unused))