On 08/31/23 at 10:56am, Leizhen (ThunderTown) wrote:
>
>
> On 2023/8/29 20:16, Baoquan He wrote:
> > Now parse_crashkernel() is a real entry point for all kinds of
> > crahskernel parsing on any architecture.
> >
> > And wrap the crahskernel=,high|low handling inside
> > CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION ifdeffery scope.
> >
> > Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> > ---
> > include/linux/crash_core.h | 6 ++++++
> > kernel/crash_core.c | 28 +++++++++++++++++++++++++++-
> > 2 files changed, 33 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
> > index 2e76289699ff..85260bf4a734 100644
> > --- a/include/linux/crash_core.h
> > +++ b/include/linux/crash_core.h
> > @@ -77,6 +77,12 @@ Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
> > void *data, size_t data_len);
> > void final_note(Elf_Word *buf);
> >
> > +#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
> > +#ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE
> > +#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20)
> > +#endif
> > +#endif
> > +
> > int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
> > unsigned long long *crash_size, unsigned long long *crash_base,
> > unsigned long long *low_size, bool *high);
> > diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> > index f6a5c219e2e1..355b0ab5189c 100644
> > --- a/kernel/crash_core.c
> > +++ b/kernel/crash_core.c
> > @@ -276,6 +276,9 @@ static int __init __parse_crashkernel(char *cmdline,
> > /*
> > * That function is the entry point for command line parsing and should be
> > * called from the arch-specific code.
> > + *
> > + * If crashkernel=,high|low is supported on architecture, non-NULL values
> > + * should be passed to parameters 'low_size' and 'high'.
> > */
> > int __init parse_crashkernel(char *cmdline,
> > unsigned long long system_ram,
> > @@ -291,7 +294,30 @@ int __init parse_crashkernel(char *cmdline,
> > crash_base, NULL);
> > if (!high)
> > return ret;
> > -
> > +#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
> > + else if (ret == -ENOENT) {
> > + ret = __parse_crashkernel(cmdline, 0, crash_size,
> > + crash_base, suffix_tbl[SUFFIX_HIGH]);
> > + if (ret || !*crash_size)
> > + return -1;
>
> Change -1 to -EINVAL?
Thanks a lot for careful reviewing, Zhen Lei.
Here, it's fine to me, parse_crashkernel() returns 0 on success, other value
on failure. '-1' or '-EINVAL' is not different to me in this case. I can
update if you think '-EINVAL' is better.
>
> > +
> > + /*
> > + * crashkernel=Y,low can be specified or not, but invalid value
> > + * is not allowed.
> > + */
> > + ret = __parse_crashkernel(cmdline, 0, low_size,
> > + crash_base, suffix_tbl[SUFFIX_LOW]);
> > + if (ret == -ENOENT)
> > + *low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
> > + else if (ret)
> > + return -1;
>
> return ret;
Ditto.
>
> > +
> > + *high = true;
> > + } else if (ret || !*crash_size) {
>
> This check can be moved outside of #ifdef. Because even '!high', it's completely
> applicable. The overall adjustment is as follows:
Hmm, the current logic is much easier to understand. However, I may not
100% get your suggestion. Can you paste the complete code in your
suggested way? Do not need 100% correct code, just the skeleton of code logic
so that I can better understand it and add inline comment.
>
> - if (!high)
> - return ret;
>
> #ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
> if (high && ret == -ENOENT) {
> ... ...
> if (ret || !*crash_size) //parse HIGH
> ... ...
> }
>
> //At this point, *crash_size is not 0 and ret is 0.
> //We can also delete if (!*crash_size) above because it will be checked later.
> #endif
>
> if (!*crash_size)
> ret = -EINVAL;
>
> return ret;
When crashkernel=,high is specified while crashkernel=,low is omitted,
the ret==-ENOENT, but we can't return ret directly. That is still an
acceptable way.
>
> - return 0;
>
> > + /* The specified value is invalid */
> > + return -1;
> > + }
> > +#endif
> > return 0;
> > }
> >
> >
>
> --
> Regards,
> Zhen Lei
>
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