From 75e2f0a6b16141cb347f442033ec907380d4d66e Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 19 Jul 2017 14:53:00 +0200 Subject: [PATCH] x86/fpu/math-emu: Fix possible uninitialized variable use MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When building the kernel with "make EXTRA_CFLAGS=...", this overrides the "PARANOID" preprocessor macro defined in arch/x86/math-emu/Makefile, and we run into a build warning: arch/x86/math-emu/reg_compare.c: In function ‘compare_i_st_st’: arch/x86/math-emu/reg_compare.c:254:6: error: ‘f’ may be used uninitialized in this function [-Werror=maybe-uninitialized] This fixes the implementation to work correctly even without the PARANOID flag, and also fixes the Makefile to not use the EXTRA_CFLAGS variable but instead use the ccflags-y variable in the Makefile that is meant for this purpose. Signed-off-by: Arnd Bergmann Cc: Bill Metzenthen Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170719125310.2487451-3-arnd@arndb.de Signed-off-by: Ingo Molnar --- arch/x86/math-emu/Makefile | 4 ++-- arch/x86/math-emu/reg_compare.c | 16 ++++++++-------- 2 files changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/x86/math-emu/Makefile b/arch/x86/math-emu/Makefile index 9b0c63b60302..1b2dac174321 100644 --- a/arch/x86/math-emu/Makefile +++ b/arch/x86/math-emu/Makefile @@ -5,8 +5,8 @@ #DEBUG = -DDEBUGGING DEBUG = PARANOID = -DPARANOID -EXTRA_CFLAGS := $(PARANOID) $(DEBUG) -fno-builtin $(MATH_EMULATION) -EXTRA_AFLAGS := $(PARANOID) +ccflags-y += $(PARANOID) $(DEBUG) -fno-builtin $(MATH_EMULATION) +asflags-y += $(PARANOID) # From 'C' language sources: C_OBJS =fpu_entry.o errors.o \ diff --git a/arch/x86/math-emu/reg_compare.c b/arch/x86/math-emu/reg_compare.c index b77360fdbf4a..19b33b50adfa 100644 --- a/arch/x86/math-emu/reg_compare.c +++ b/arch/x86/math-emu/reg_compare.c @@ -168,7 +168,7 @@ static int compare(FPU_REG const *b, int tagb) /* This function requires that st(0) is not empty */ int FPU_compare_st_data(FPU_REG const *loaded_data, u_char loaded_tag) { - int f = 0, c; + int f, c; c = compare(loaded_data, loaded_tag); @@ -189,12 +189,12 @@ int FPU_compare_st_data(FPU_REG const *loaded_data, u_char loaded_tag) case COMP_No_Comp: f = SW_C3 | SW_C2 | SW_C0; break; -#ifdef PARANOID default: +#ifdef PARANOID EXCEPTION(EX_INTERNAL | 0x121); +#endif /* PARANOID */ f = SW_C3 | SW_C2 | SW_C0; break; -#endif /* PARANOID */ } setcc(f); if (c & COMP_Denormal) { @@ -205,7 +205,7 @@ int FPU_compare_st_data(FPU_REG const *loaded_data, u_char loaded_tag) static int compare_st_st(int nr) { - int f = 0, c; + int f, c; FPU_REG *st_ptr; if (!NOT_EMPTY(0) || !NOT_EMPTY(nr)) { @@ -235,12 +235,12 @@ static int compare_st_st(int nr) case COMP_No_Comp: f = SW_C3 | SW_C2 | SW_C0; break; -#ifdef PARANOID default: +#ifdef PARANOID EXCEPTION(EX_INTERNAL | 0x122); +#endif /* PARANOID */ f = SW_C3 | SW_C2 | SW_C0; break; -#endif /* PARANOID */ } setcc(f); if (c & COMP_Denormal) { @@ -283,12 +283,12 @@ static int compare_i_st_st(int nr) case COMP_No_Comp: f = X86_EFLAGS_ZF | X86_EFLAGS_PF | X86_EFLAGS_CF; break; -#ifdef PARANOID default: +#ifdef PARANOID EXCEPTION(EX_INTERNAL | 0x122); +#endif /* PARANOID */ f = 0; break; -#endif /* PARANOID */ } FPU_EFLAGS = (FPU_EFLAGS & ~(X86_EFLAGS_ZF | X86_EFLAGS_PF | X86_EFLAGS_CF)) | f; if (c & COMP_Denormal) { -- 2.39.2