Commit 746bb4ed authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'vla-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull VLA removal from Kees Cook:
 "Globally warn on VLA use.

  This turns on "-Wvla" globally now that the last few trees with their
  VLA removals have landed (crypto, block, net, and powerpc).

  Arnd mentioned that there may be a couple more VLAs hiding in
  hard-to-find randconfigs, but nothing big has shaken out in the last
  month or so in linux-next.

  We should be basically VLA-free now! Wheee. :)

  Summary:

   - Remove unused fallback for BUILD_BUG_ON (which technically contains
     a VLA)

   - Lift -Wvla to the top-level Makefile"

* tag 'vla-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Makefile: Globally enable VLA warning
  compiler.h: give up __compiletime_assert_fallback()
parents ac747c07 0bb95f80
...@@ -801,6 +801,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) ...@@ -801,6 +801,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
# warn about C99 declaration after statement # warn about C99 declaration after statement
KBUILD_CFLAGS += -Wdeclaration-after-statement KBUILD_CFLAGS += -Wdeclaration-after-statement
# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
KBUILD_CFLAGS += $(call cc-option,-Wvla)
# disable pointer signed / unsigned warnings in gcc 4.0 # disable pointer signed / unsigned warnings in gcc 4.0
KBUILD_CFLAGS += -Wno-pointer-sign KBUILD_CFLAGS += -Wno-pointer-sign
......
...@@ -12,7 +12,7 @@ ...@@ -12,7 +12,7 @@
# Note the danger in using -Wall -Wextra is that when CI updates gcc we # Note the danger in using -Wall -Wextra is that when CI updates gcc we
# will most likely get a sudden build breakage... Hopefully we will fix # will most likely get a sudden build breakage... Hopefully we will fix
# new warnings before CI updates! # new warnings before CI updates!
subdir-ccflags-y := -Wall -Wextra -Wvla subdir-ccflags-y := -Wall -Wextra
subdir-ccflags-y += $(call cc-disable-warning, unused-parameter) subdir-ccflags-y += $(call cc-disable-warning, unused-parameter)
subdir-ccflags-y += $(call cc-disable-warning, type-limits) subdir-ccflags-y += $(call cc-disable-warning, type-limits)
subdir-ccflags-y += $(call cc-disable-warning, missing-field-initializers) subdir-ccflags-y += $(call cc-disable-warning, missing-field-initializers)
......
...@@ -344,29 +344,14 @@ static inline void *offset_to_ptr(const int *off) ...@@ -344,29 +344,14 @@ static inline void *offset_to_ptr(const int *off)
#endif #endif
#ifndef __compiletime_error #ifndef __compiletime_error
# define __compiletime_error(message) # define __compiletime_error(message)
/*
* Sparse complains of variable sized arrays due to the temporary variable in
* __compiletime_assert. Unfortunately we can't just expand it out to make
* sparse see a constant array size without breaking compiletime_assert on old
* versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
*/
# ifndef __CHECKER__
# define __compiletime_error_fallback(condition) \
do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
# endif
#endif
#ifndef __compiletime_error_fallback
# define __compiletime_error_fallback(condition) do { } while (0)
#endif #endif
#ifdef __OPTIMIZE__ #ifdef __OPTIMIZE__
# define __compiletime_assert(condition, msg, prefix, suffix) \ # define __compiletime_assert(condition, msg, prefix, suffix) \
do { \ do { \
int __cond = !(condition); \
extern void prefix ## suffix(void) __compiletime_error(msg); \ extern void prefix ## suffix(void) __compiletime_error(msg); \
if (__cond) \ if (!(condition)) \
prefix ## suffix(); \ prefix ## suffix(); \
__compiletime_error_fallback(__cond); \
} while (0) } while (0)
#else #else
# define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0) # define __compiletime_assert(condition, msg, prefix, suffix) do { } while (0)
......
...@@ -53,7 +53,9 @@ obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o ...@@ -53,7 +53,9 @@ obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o
obj-$(CONFIG_TEST_IDA) += test_ida.o obj-$(CONFIG_TEST_IDA) += test_ida.o
obj-$(CONFIG_TEST_KASAN) += test_kasan.o obj-$(CONFIG_TEST_KASAN) += test_kasan.o
CFLAGS_test_kasan.o += -fno-builtin CFLAGS_test_kasan.o += -fno-builtin
CFLAGS_test_kasan.o += $(call cc-disable-warning, vla)
obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o
CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla)
UBSAN_SANITIZE_test_ubsan.o := y UBSAN_SANITIZE_test_ubsan.o := y
obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
......
...@@ -52,7 +52,6 @@ warning-3 += -Wpointer-arith ...@@ -52,7 +52,6 @@ warning-3 += -Wpointer-arith
warning-3 += -Wredundant-decls warning-3 += -Wredundant-decls
warning-3 += -Wswitch-default warning-3 += -Wswitch-default
warning-3 += $(call cc-option, -Wpacked-bitfield-compat) warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
warning-3 += $(call cc-option, -Wvla)
warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
......
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