Created attachment 468636 [details]
preprocessed source

code snippet from tools/perf/util/ui/browser.c

...
void ui_browser__add_exit_keys(struct ui_browser *self, int keys[])
{
        int i = 0;

        while (keys[i] && i < 64) {
                ui_browser__add_exit_key(self, keys[i]);
                ++i;
        }
}
        
int ui_browser__show(struct ui_browser *self, const char *title,
                     const char *helpline, ...)
{
        va_list ap;
        int keys[] = { NEWT_KEY_UP, NEWT_KEY_DOWN, NEWT_KEY_PGUP,
                       NEWT_KEY_PGDN, NEWT_KEY_HOME, NEWT_KEY_END, ' ',
                       NEWT_KEY_LEFT, NEWT_KEY_ESCAPE, 'q', CTRL('c'), 0 };

        if (self->form != NULL)
                newtFormDestroy(self->form);

        ui_browser__refresh_dimensions(self);
        self->form = newtForm(NULL, NULL, 0);
        if (self->form == NULL)
                return -1;

        self->sb = newtVerticalScrollbar(self->width, 1, self->height,
                                         HE_COLORSET_NORMAL,
                                         HE_COLORSET_SELECTED);
        if (self->sb == NULL)
                return -1;

        SLsmg_gotorc(0, 0);
        ui_browser__set_color(self, NEWT_COLORSET_ROOT);
        slsmg_write_nstring(title, self->width);

        ui_browser__add_exit_keys(self, keys);
        newtFormAddComponent(self->form, self->sb);

        va_start(ap, helpline);
        ui_helpline__vpush(helpline, ap);
        va_end(ap);
        return 0;
}
...

Compile on s390x fails with

gcc -o util/ui/browser.o -c -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -D_FORTIFY_SOURCE=2 -Wformat -Wformat-security -Wformat-y2k -Wshadow -Winit-self -Wpacked -Wredundant-decls -Wstack-protector -Wstrict-aliasing=3 -Wswitch-default -Wswitch-enum -Wno-system-headers -Wundef -Wvolatile-register-var -Wwrite-strings -Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes -Wdeclaration-after-statement  -fstack-protector-all -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Iutil/include -Iarch/s390/include -DLIBELF_NO_MMAP -I/usr/include/slang -DNO_STRLCPY -DSHA1_HEADER='<openssl/sha.h>'  -DENABLE_SLFUTURE_CONST util/ui/browser.c
cc1: warnings being treated as errors
util/ui/browser.c: In function ‘ui_browser__show’:
util/ui/browser.c:153:13: error: array subscript is above array bounds
...

while it compiles fine on x86_64, line 153 is the "while (keys[i] && i < 64)" condition

tested with  gcc-4.5.1-4 in F-14 and gcc-4.5.1-6 in koji