Messages in this thread | | | From | Nick Desaulniers <> | Date | Tue, 11 Oct 2022 14:20:36 -0700 | Subject | Re: [PATCH -next v4 2/2] x86/boot/compressed: Add "-Wall" flag to Makefile |
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On Mon, Oct 10, 2022 at 6:32 PM Li Zetao <lizetao1@huawei.com> wrote: > > Compressed/Makefile does not have "-Wall" flag, this is the old problem of > x86 not sharing makefiles. Fix by adding "-Wall" flag to Makefile. But when > "-Wall" flag added to Makefile, a few extra warnings were found. > > 1. > In file included from arch/x86/boot/compressed/misc.c:15: > In file included from arch/x86/boot/compressed/misc.h:24: > In file included from ./include/linux/elf.h:6: > In file included from ./arch/x86/include/asm/elf.h:8: > In file included from ./include/linux/thread_info.h:60: > ./arch/x86/include/asm/thread_info.h:175:13: warning: calling > "__builtin_frame_address" with a nonzero argument is unsafe > [-Wframe-address] > oldframe = __builtin_frame_address(1); > ^~~~~~~~~~~~~~~~~~~~~~~~~~ > > ./arch/x86/include/asm/thread_info.h:177:11: warning: calling > "__builtin_frame_address" with a nonzero argument is unsafe > [-Wframe-address] > frame = __builtin_frame_address(2); > ^~~~~~~~~~~~~~~~~~~~~~~~~~ > > This warning is disabled in the main Makefile for this reason so we > should just be able to disable it, adding "frame-address" flag to > Makefile. > > 2. > arch/x86/boot/compressed/kaslr.c:627:6: warning: unused variable > "i" [-Wunused-variable] > int i; > ^ > > This happens when CONFIG_MEMORY_HOTREMOVE or CONFIG_ACPI are "n". > Fix by adding "-std=gnu11" flag to Makefile, and we should put > the variable "i" within the for loop. > > 3. > arch/x86/boot/compressed/acpi.c:23:1: warning: unused function > "__efi_get_rsdp_addr" [-Wunused-function] > > This happens when CONFIG_EFI is disabled for the reason that > function "__efi_get_rsdp_addr" is only called in efi_get_rsdp_addr > when CONFIG_EFI enable. So function "__efi_get_rsdp_addr" should > not be defined when CONFIG_EFI is disabled. > > Signed-off-by: Li Zetao <lizetao1@huawei.com>
I gave this a quick spin with clang to ensure that I didn't observe new warnings produced via -Wall:
$ make LLVM=1 -j128 -s defconfig all $ make LLVM=1 ARCH=i386 -j128 -s defconfig all
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> --- > v1 -> v2: Patch is new > v2 -> v3: Resolve extra warnings after "-Wall" flag added > v3 -> v4: Put this patch at the end > > arch/x86/boot/compressed/Makefile | 3 ++- > arch/x86/boot/compressed/acpi.c | 5 +++-- > arch/x86/boot/compressed/kaslr.c | 3 +-- > 3 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile > index 3a261abb6d15..8918a8306dff 100644 > --- a/arch/x86/boot/compressed/Makefile > +++ b/arch/x86/boot/compressed/Makefile > @@ -35,7 +35,7 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ > # be valid. > KBUILD_CFLAGS := -m$(BITS) -O2 $(CLANG_FLAGS) > KBUILD_CFLAGS += -fno-strict-aliasing -fPIE > -KBUILD_CFLAGS += -Wundef > +KBUILD_CFLAGS += -Wundef -Wall -std=gnu11 > KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING > cflags-$(CONFIG_X86_32) := -march=i386 > cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone > @@ -44,6 +44,7 @@ KBUILD_CFLAGS += -mno-mmx -mno-sse > KBUILD_CFLAGS += -ffreestanding -fshort-wchar > KBUILD_CFLAGS += -fno-stack-protector > KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) > +KBUILD_CFLAGS += $(call cc-disable-warning, frame-address) > KBUILD_CFLAGS += $(call cc-disable-warning, gnu) > KBUILD_CFLAGS += -Wno-pointer-sign > KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) > diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c > index 21febd9f21ab..c062a8230e9c 100644 > --- a/arch/x86/boot/compressed/acpi.c > +++ b/arch/x86/boot/compressed/acpi.c > @@ -19,10 +19,10 @@ > */ > struct mem_vector immovable_mem[MAX_NUMNODES*2]; > > +#ifdef CONFIG_EFI > static acpi_physical_address > __efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len) > { > -#ifdef CONFIG_EFI > unsigned long rsdp_addr; > > /* > @@ -41,9 +41,10 @@ __efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len) > return (acpi_physical_address)rsdp_addr; > > debug_putstr("Error getting RSDP address.\n"); > -#endif > + > return 0; > } > +#endif > > static acpi_physical_address efi_get_rsdp_addr(void) > { > diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c > index e476bcbd9b42..4abc9c42cf4d 100644 > --- a/arch/x86/boot/compressed/kaslr.c > +++ b/arch/x86/boot/compressed/kaslr.c > @@ -625,7 +625,6 @@ static bool process_mem_region(struct mem_vector *region, > unsigned long minimum, > unsigned long image_size) > { > - int i; > /* > * If no immovable memory found, or MEMORY_HOTREMOVE disabled, > * use @region directly. > @@ -645,7 +644,7 @@ static bool process_mem_region(struct mem_vector *region, > * If immovable memory found, filter the intersection between > * immovable memory and @region. > */ > - for (i = 0; i < num_immovable_mem; i++) { > + for (int i = 0; i < num_immovable_mem; i++) { > u64 start, end, entry_end, region_end; > struct mem_vector entry; > > -- > 2.34.1 >
-- Thanks, ~Nick Desaulniers
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