On 23 August 2017 at 15:05, Arnd Bergmann <a...@arndb.de> wrote: > gcc-8 correctly points out that reading four bytes from a pointer to a > 'char' variable is wrong > > arch/arm/kernel/vdso.c: In function 'vdso_init': > arch/arm/kernel/vdso.c:200:6: error: '__builtin_memcmp_eq' reading 4 bytes > from a region of size 1 [-Werror=stringop-overflow=] > > However, in this case the variable just stands for the beginning of the > vdso and is not actually a 'char', so the code is doing what it is meant > to do. > > Not sure what the best solution for this is, changing the hack to > declare the variable as 'int' instead makes the warning go away. > > Signed-off-by: Arnd Bergmann <a...@arndb.de> > --- > arch/arm/include/asm/vdso.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/vdso.h b/arch/arm/include/asm/vdso.h > index d0295f1dd1a3..eff7d3a1d1ce 100644 > --- a/arch/arm/include/asm/vdso.h > +++ b/arch/arm/include/asm/vdso.h > @@ -11,7 +11,7 @@ struct mm_struct; > > void arm_install_vdso(struct mm_struct *mm, unsigned long addr); > > -extern char vdso_start, vdso_end; > +extern int vdso_start, vdso_end; > > extern unsigned int vdso_total_pages; >
May I suggest extern char vdso_start[], vdso_end[];
