Messages in this thread | | | Date | Tue, 12 May 2015 09:23:03 +0200 | From | Richard Weinberger <> | Subject | Re: [PATCH 1/2] Fix printk() on ERR_PTR() |
| |
Am 12.05.2015 um 01:20 schrieb Andrew Morton: > On Sun, 10 May 2015 21:42:15 +0200 Richard Weinberger <richard@nod.at> wrote: > >> vbin_printf() checks whether the provided pointer is larger >> than -PAGE_SIZE such that it does not explode on ERR_PTR() pointers. >> printk() does not. >> >> Let's add this check also to the printk() code such that >> trace_printk() and printk() are consistent again. >> >> .. >> >> --- a/lib/vsprintf.c >> +++ b/lib/vsprintf.c >> @@ -511,7 +511,8 @@ char *string(char *buf, char *end, const char *s, struct printf_spec spec) >> { >> int len, i; >> >> - if ((unsigned long)s < PAGE_SIZE) >> + if ((unsigned long)s > (unsigned long)-PAGE_SIZE || > > hm, PAGE_SIZE has type ulong, so is the cast needed?
But we add a negative sign to it. AFAIK the cast is needed to prevent gcc from promoting this to a signed long.
>> + (unsigned long)s < PAGE_SIZE) > > This would be a place for > > if (!within(PAGE_SIZE, (unsigned long)s, -PAGE_SIZE)) > s = "(null)"; > > I'm counting at least five implementations of within(), not all the same.
Challenge accepted. :D
Thanks, //richard
| |