On Sun, Apr 28, 2019 at 4:37 PM Dave Young <dyoung@xxxxxxxxxx> wrote: > > On 04/25/19 at 04:20pm, Pingfan Liu wrote: > > On Wed, Apr 24, 2019 at 4:31 PM Matthias Brugger <mbrugger@xxxxxxxx> wrote: > > > > > > > > [...] > > > > @@ -139,6 +141,8 @@ static int __init parse_crashkernel_simple(char *cmdline, > > > > pr_warn("crashkernel: unrecognized char: %c\n", *cur); > > > > return -EINVAL; > > > > } > > > > + if (*crash_size == 0) > > > > + return -EINVAL; > > > > > > This covers the case where I pass an argument like "crashkernel=0M" ? > > > Can't we fix that by using kstrtoull() in memparse and check if the return value > > > is < 0? In that case we could return without updating the retptr and we will be > > > fine. > > > > > It seems that kstrtoull() treats 0M as invalid parameter, while > > simple_strtoull() does not. > > > > If changed like your suggestion, then all the callers of memparse() > > will treats 0M as invalid parameter. This affects many components > > besides kexec. Not sure this can be done or not. > > simple_strtoull is obsolete, move to kstrtoull is the right way. > > $ git grep memparse|wc > 158 950 10479 > > Except some documentation/tools etc there are still a log of callers > which directly use the return value as the ull number without error > checking. > > So it would be good to mark memparse as obsolete as well in > lib/cmdline.c, and introduce a new function eg. kmemparse() to use > kstrtoull, and return a real error code, and save the size in an > argument like &size. Then update X86 crashkernel code to use it. > Thank for your good suggestion. Regards, Pingfan