On Thu, Oct 14, 2021 at 11:17 AM HAGIO KAZUHITO(萩尾 一仁)
<k-hagio-ab@xxxxxxx> wrote:
>
> Hi Ankur,
>
> -----Original Message-----
> > >> assign page_offset and kvbase based on VA_BITS passed
> > >>
> >
> > >Thank you for the patch, Ankur.
> > >Can you help to describe the reason in detail? And what happened?
> >
> >
> >
> > Hi Lianbo, Raw ramdump without vmcoreinfo doesn't work here.
> > read_vmcoreinfo("NUMBER(BA_BITS)") will not work on raw ramdump.
> > getting below error
> >
Thank you for the information, Ankur.
> > crash_64: vmlinux and /var/tmp/ramdump_elf_XUtCMT do not match!
> > Usage:
> > crash [OPTION]... NAMELIST MEMORY-IMAGE[@address <https://github.com/address> ] (dumpfile form)
> > crash [OPTION]... [NAMELIST] (live system form)
> > Enter "crash_64 -h" for details.
> >
> > Recent change https://github.com/crash-utility/crash/commit/167d37e347fe35c6f7db826e8539e192c4375564 is
> > causing this issue, before this change VA_BITS_ACTUAL was used which is passed from cmd line.
>
> ok, I see, but I'm not sure why your patch uses the (pc->flags2 & SNAP) condition.
This seems not very reasonable, the SNAP flag has a specific use.
> The calculation used VA_BITS_ACTUAL (== VA_BITS for ramdump) before the change,
> so how about the following patch?
>./crash
> diff --git a/arm64.c b/arm64.c
> index 7069312671cf..da78acbb013f 100644
> --- a/arm64.c
> +++ b/arm64.c
> @@ -4031,6 +4031,9 @@ arm64_calc_VA_BITS(void)
> error(FATAL, "cannot determine VA_BITS_ACTUAL\n");
> }
>
> + if (!machdep->machspec->CONFIG_ARM64_VA_BITS) /* guess */
> + machdep->machspec->CONFIG_ARM64_VA_BITS = machedp->machspec->VA_BITS;
> +
Looks good.
> /*
> * The mm flip commit is introduced before 52-bits VA, which is before the
> * commit to export NUMBER(TCR_EL1_T1SZ)
>
BTW: Can we also try to get its value from kernel config? But this
relies on kernel config: CONFIG_IKCONFIG.
diff --git a/arm64.c b/arm64.c
index 7069312..79f9929 100644
--- a/arm64.c
+++ b/arm64.c
@@ -3989,6 +3989,10 @@ arm64_calc_VA_BITS(void)
value = atol(string);
free(string);
machdep->machspec->CONFIG_ARM64_VA_BITS = value;
+ } else if (kt->ikconfig_flags & IKCONFIG_AVAIL) {
+ if ((get_kernel_config("CONFIG_ARM64_VA_BITS",
+ &string)) == IKCONFIG_STR)
+ machdep->machspec->CONFIG_ARM64_VA_BITS = atol(string);
}
if (kernel_symbol_exists("vabits_actual")) {
Thanks.
Lianbo
> > 3987 static void
> > 3988 arm64_calc_VA_BITS(void)
> > 3989 {
> > 3990 int bitval;
> > 3991 struct syment *sp;
> > 3992 ulong vabits_actual, value;
> > 3993 char *string;
> > 3994
> > 3995 if ((string = pc->read_vmcoreinfo("NUMBER(VA_BITS)"))) {
> > 3996 value = atol(string);
> > 3997 free(string);
> > 3998 machdep->machspec->CONFIG_ARM64_VA_BITS = value;
> > 3999 }
> >
> >
> >
> >
> > >Thanks.
> > >Lianbo
> >
> > >> Change-Id: I525f3c7fd91e1f06e909c2f4c1749c44c068baea
> > >> Signed-off-by: Ankur Bansal <er.ankurbansal@xxxxxxxxx <mailto:er.ankurbansal@xxxxxxxxx> >
> > >> ---
> > >> arm64.c | 15 +++++++++++----
> > >> 1 file changed, 11 insertions(+), 4 deletions(-)
> > >>
> > >> diff --git a/arm64.c b/arm64.c
> > >> index 7069312..2dc77f7 100644
> > >> --- a/arm64.c
> > >> +++ b/arm64.c
> > >> @@ -220,10 +220,17 @@ arm64_init(int when)
> > >>
> > >> /* vabits_actual introduced after mm flip, so it should be flipped layout */
> > >> if (ms->VA_BITS_ACTUAL) {
> > >> - ms->page_offset = ARM64_FLIP_PAGE_OFFSET;
> > >> - /* useless on arm64 */
> > >> - machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET;
> > >> - machdep->kvbase = ARM64_FLIP_PAGE_OFFSET;
> > >> + if ((pc->flags2 & SNAP)) {
> > >> + ms->page_offset = ARM64_FLIP_PAGE_OFFSET;
> > >> + /* useless on arm64 */
> > >> + machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET;
> > >> + machdep->kvbase = ARM64_FLIP_PAGE_OFFSET;
> > >> + }
> > >> + else{
> > >> + ms->page_offset = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
> > >> + machdep->identity_map_base = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
> > >> + machdep->kvbase = ARM64_FLIP_PAGE_OFFSET_ACTUAL;
> > >> + }
> > >> ms->userspace_top = ARM64_USERSPACE_TOP_ACTUAL;
> > >> } else {
> > >> ms->page_offset = ARM64_PAGE_OFFSET;
> > >> --
> > >> 2.7.4
> >
> >
> >
> > ------------------------------
> >
> > --
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> > Crash-utility@xxxxxxxxxx <mailto:Crash-utility@xxxxxxxxxx>
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> >
> > End of Crash-utility Digest, Vol 192, Issue 28
> > **********************************************
> >
> >
> >
>
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