Messages in this thread | | | Date | Sun, 28 Apr 2019 16:37:10 +0800 | From | Dave Young <> | Subject | Re: [PATCHv2] kernel/crash: make parse_crashkernel()'s return value more indicant |
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On 04/25/19 at 04:20pm, Pingfan Liu wrote: > On Wed, Apr 24, 2019 at 4:31 PM Matthias Brugger <mbrugger@suse.com> 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simple_strtoull is obsolete, move to kstrtoull is the right way.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.
Thanks Dave
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