From: Geert Uytterhoeven Date: Sun, 6 Jan 2019 10:47:00 +0000 (+0100) Subject: m68k: Avoid VLA use in mangle_kernel_stack() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=35f61d7b3ba36f85dacc20c62e5d0dca0807bc77;p=linux.git m68k: Avoid VLA use in mangle_kernel_stack() With gcc 7.3.0: arch/m68k/kernel/signal.c: In function ‘mangle_kernel_stack’: arch/m68k/kernel/signal.c:654:3: warning: ISO C90 forbids variable length array ‘buf’ [-Wvla] unsigned long buf[fsize / 2]; /* yes, twice as much */ ^~~~~~~~ Replace the variable size by the upper limit, which is 168 bytes. Signed-off-by: Geert Uytterhoeven Acked-by: Arnd Bergmann --- diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c index e2a9421c57975..87e7f3639839f 100644 --- a/arch/m68k/kernel/signal.c +++ b/arch/m68k/kernel/signal.c @@ -651,7 +651,8 @@ static int mangle_kernel_stack(struct pt_regs *regs, int formatvec, regs->vector = formatvec & 0xfff; } else { struct switch_stack *sw = (struct switch_stack *)regs - 1; - unsigned long buf[fsize / 2]; /* yes, twice as much */ + /* yes, twice as much as max(sizeof(frame.un.fmt)) */ + unsigned long buf[sizeof(((struct frame *)0)->un) / 2]; /* that'll make sure that expansion won't crap over data */ if (copy_from_user(buf + fsize / 4, fp, fsize))