* [PATCH,RFC] - make /proc/vmcore accesable on x86_64
@ 2010-10-19 15:06 Jiri Olsa
2010-10-22 8:54 ` Simon Horman
0 siblings, 1 reply; 5+ messages in thread
From: Jiri Olsa @ 2010-10-19 15:06 UTC (permalink / raw)
To: kexec; +Cc: horms
hi,
I was playing around with preserve context feature on x86_64
and was not able to get the /proc/vmcore in the kexec-ed
kernel until I aplied attached patch.
I'm not at all sure this is right fix ;) but it seems
that /proc/vmcore is not loaded since the machine field in the
elf header is wrong.
If the x86_64 arch returns 0 (KEXEC_ARCH_DEFAULT) then following
condition in load_crashdump_segments function will fill 386 as the
machine for the vmcore elf header..
...
if ((info->kexec_flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_X86_64)
{
elf_info.machine = EM_X86_64;
} else {
elf_info.machine = EM_386;
elf_info.lowmem_limit = X86_MAXMEM;
elf_info.get_note_info = get_crash_notes;
}
...
ending with kexec-ed kernel failing check for the machine,
and disabling vmcore interface...
I'm guessing that the reason is the load_crashdump_segments function
being shared among 32 and 64 bits.. but again, not sure ;)
My goal is to share data within the host and kexec-ed kernel,
so I'd like to use the /proc/vmcore for that.. any other
ideas are welcome :)
thanks,
jirka
---
diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index 06e5ae9..40f989a 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -691,6 +691,8 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
struct memory_range *mem_range, *memmap_p;
struct crash_elf_info elf_info;
+ memset(&elf_info, 0x0, sizeof(elf_info));
+
/* Constant parts of the elf_info */
elf_info.data = ELFDATA2LSB;
elf_info.backup_src_start = BACKUP_SRC_START;
diff --git a/kexec/arch/x86_64/kexec-x86_64.c b/kexec/arch/x86_64/kexec-x86_64.c
index 3092643..c34fd92 100644
--- a/kexec/arch/x86_64/kexec-x86_64.c
+++ b/kexec/arch/x86_64/kexec-x86_64.c
@@ -134,10 +134,7 @@ int arch_process_options(int argc, char **argv)
}
const struct arch_map_entry arches[] = {
- /* For compatibility with older patches
- * use KEXEC_ARCH_DEFAULT instead of KEXEC_ARCH_X86_64 here.
- */
- { "x86_64", KEXEC_ARCH_DEFAULT },
+ { "x86_64", KEXEC_ARCH_X86_64 },
{ NULL, 0 },
};
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH,RFC] - make /proc/vmcore accesable on x86_64
2010-10-19 15:06 [PATCH,RFC] - make /proc/vmcore accesable on x86_64 Jiri Olsa
@ 2010-10-22 8:54 ` Simon Horman
2010-10-28 12:16 ` Simon Horman
0 siblings, 1 reply; 5+ messages in thread
From: Simon Horman @ 2010-10-22 8:54 UTC (permalink / raw)
To: Jiri Olsa; +Cc: kexec
On Tue, Oct 19, 2010 at 05:06:30PM +0200, Jiri Olsa wrote:
> hi,
>
> I was playing around with preserve context feature on x86_64
> and was not able to get the /proc/vmcore in the kexec-ed
> kernel until I aplied attached patch.
>
> I'm not at all sure this is right fix ;) but it seems
> that /proc/vmcore is not loaded since the machine field in the
> elf header is wrong.
>
>
> If the x86_64 arch returns 0 (KEXEC_ARCH_DEFAULT) then following
> condition in load_crashdump_segments function will fill 386 as the
> machine for the vmcore elf header..
>
> ...
>
> if ((info->kexec_flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_X86_64)
> {
> elf_info.machine = EM_X86_64;
> } else {
> elf_info.machine = EM_386;
> elf_info.lowmem_limit = X86_MAXMEM;
> elf_info.get_note_info = get_crash_notes;
> }
> ...
>
> ending with kexec-ed kernel failing check for the machine,
> and disabling vmcore interface...
>
>
> I'm guessing that the reason is the load_crashdump_segments function
> being shared among 32 and 64 bits.. but again, not sure ;)
>
>
> My goal is to share data within the host and kexec-ed kernel,
> so I'd like to use the /proc/vmcore for that.. any other
> ideas are welcome :)
This approach seems reasonable to me.
I'll push it if a I don't hear any objections
in the near future.
>
>
> thanks,
> jirka
> ---
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index 06e5ae9..40f989a 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -691,6 +691,8 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> struct memory_range *mem_range, *memmap_p;
> struct crash_elf_info elf_info;
>
> + memset(&elf_info, 0x0, sizeof(elf_info));
> +
> /* Constant parts of the elf_info */
> elf_info.data = ELFDATA2LSB;
> elf_info.backup_src_start = BACKUP_SRC_START;
> diff --git a/kexec/arch/x86_64/kexec-x86_64.c b/kexec/arch/x86_64/kexec-x86_64.c
> index 3092643..c34fd92 100644
> --- a/kexec/arch/x86_64/kexec-x86_64.c
> +++ b/kexec/arch/x86_64/kexec-x86_64.c
> @@ -134,10 +134,7 @@ int arch_process_options(int argc, char **argv)
> }
>
> const struct arch_map_entry arches[] = {
> - /* For compatibility with older patches
> - * use KEXEC_ARCH_DEFAULT instead of KEXEC_ARCH_X86_64 here.
> - */
> - { "x86_64", KEXEC_ARCH_DEFAULT },
> + { "x86_64", KEXEC_ARCH_X86_64 },
> { NULL, 0 },
> };
>
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH,RFC] - make /proc/vmcore accesable on x86_64
2010-10-22 8:54 ` Simon Horman
@ 2010-10-28 12:16 ` Simon Horman
2010-10-29 7:54 ` [PATCH] " Jiri Olsa
0 siblings, 1 reply; 5+ messages in thread
From: Simon Horman @ 2010-10-28 12:16 UTC (permalink / raw)
To: Jiri Olsa; +Cc: kexec
On Fri, Oct 22, 2010 at 10:54:12AM +0200, Simon Horman wrote:
> On Tue, Oct 19, 2010 at 05:06:30PM +0200, Jiri Olsa wrote:
> > hi,
> >
> > I was playing around with preserve context feature on x86_64
> > and was not able to get the /proc/vmcore in the kexec-ed
> > kernel until I aplied attached patch.
> >
> > I'm not at all sure this is right fix ;) but it seems
> > that /proc/vmcore is not loaded since the machine field in the
> > elf header is wrong.
> >
> >
> > If the x86_64 arch returns 0 (KEXEC_ARCH_DEFAULT) then following
> > condition in load_crashdump_segments function will fill 386 as the
> > machine for the vmcore elf header..
> >
> > ...
> >
> > if ((info->kexec_flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_X86_64)
> > {
> > elf_info.machine = EM_X86_64;
> > } else {
> > elf_info.machine = EM_386;
> > elf_info.lowmem_limit = X86_MAXMEM;
> > elf_info.get_note_info = get_crash_notes;
> > }
> > ...
> >
> > ending with kexec-ed kernel failing check for the machine,
> > and disabling vmcore interface...
> >
> >
> > I'm guessing that the reason is the load_crashdump_segments function
> > being shared among 32 and 64 bits.. but again, not sure ;)
> >
> >
> > My goal is to share data within the host and kexec-ed kernel,
> > so I'd like to use the /proc/vmcore for that.. any other
> > ideas are welcome :)
>
> This approach seems reasonable to me.
> I'll push it if a I don't hear any objections
> in the near future.
Hi Jiru,
could you please submit this as a formal patch with a signed-off-by line?
> > thanks,
> > jirka
> > ---
> > diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> > index 06e5ae9..40f989a 100644
> > --- a/kexec/arch/i386/crashdump-x86.c
> > +++ b/kexec/arch/i386/crashdump-x86.c
> > @@ -691,6 +691,8 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > struct memory_range *mem_range, *memmap_p;
> > struct crash_elf_info elf_info;
> >
> > + memset(&elf_info, 0x0, sizeof(elf_info));
> > +
> > /* Constant parts of the elf_info */
> > elf_info.data = ELFDATA2LSB;
> > elf_info.backup_src_start = BACKUP_SRC_START;
> > diff --git a/kexec/arch/x86_64/kexec-x86_64.c b/kexec/arch/x86_64/kexec-x86_64.c
> > index 3092643..c34fd92 100644
> > --- a/kexec/arch/x86_64/kexec-x86_64.c
> > +++ b/kexec/arch/x86_64/kexec-x86_64.c
> > @@ -134,10 +134,7 @@ int arch_process_options(int argc, char **argv)
> > }
> >
> > const struct arch_map_entry arches[] = {
> > - /* For compatibility with older patches
> > - * use KEXEC_ARCH_DEFAULT instead of KEXEC_ARCH_X86_64 here.
> > - */
> > - { "x86_64", KEXEC_ARCH_DEFAULT },
> > + { "x86_64", KEXEC_ARCH_X86_64 },
> > { NULL, 0 },
> > };
> >
> >
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
>
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^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] - make /proc/vmcore accesable on x86_64
2010-10-28 12:16 ` Simon Horman
@ 2010-10-29 7:54 ` Jiri Olsa
2010-10-31 1:16 ` Simon Horman
0 siblings, 1 reply; 5+ messages in thread
From: Jiri Olsa @ 2010-10-29 7:54 UTC (permalink / raw)
To: Simon Horman; +Cc: kexec
On Thu, Oct 28, 2010 at 09:16:27PM +0900, Simon Horman wrote:
> On Fri, Oct 22, 2010 at 10:54:12AM +0200, Simon Horman wrote:
> > On Tue, Oct 19, 2010 at 05:06:30PM +0200, Jiri Olsa wrote:
SNIP
> > > My goal is to share data within the host and kexec-ed kernel,
> > > so I'd like to use the /proc/vmcore for that.. any other
> > > ideas are welcome :)
> >
> > This approach seems reasonable to me.
> > I'll push it if a I don't hear any objections
> > in the near future.
>
> Hi Jiru,
>
> could you please submit this as a formal patch with a signed-off-by line?
sure, it's attached
thanks,
jirka
---
hi,
I was playing around with preserve context feature on x86_64
and was not able to get the /proc/vmcore in the kexec-ed
kernel until I aplied attached patch.
If the x86_64 arch returns 0 (KEXEC_ARCH_DEFAULT) then following
condition in load_crashdump_segments function will fill 386 as the
machine for the vmcore elf header..
...
if ((info->kexec_flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_X86_64)
{
elf_info.machine = EM_X86_64;
} else {
elf_info.machine = EM_386;
elf_info.lowmem_limit = X86_MAXMEM;
elf_info.get_note_info = get_crash_notes;
}
...
ending with kexec-ed kernel failing check for the machine,
and disabling vmcore interface.
wbr,
jirka
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index 06e5ae9..40f989a 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -691,6 +691,8 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
struct memory_range *mem_range, *memmap_p;
struct crash_elf_info elf_info;
+ memset(&elf_info, 0x0, sizeof(elf_info));
+
/* Constant parts of the elf_info */
elf_info.data = ELFDATA2LSB;
elf_info.backup_src_start = BACKUP_SRC_START;
diff --git a/kexec/arch/x86_64/kexec-x86_64.c b/kexec/arch/x86_64/kexec-x86_64.c
index 3092643..c34fd92 100644
--- a/kexec/arch/x86_64/kexec-x86_64.c
+++ b/kexec/arch/x86_64/kexec-x86_64.c
@@ -134,10 +134,7 @@ int arch_process_options(int argc, char **argv)
}
const struct arch_map_entry arches[] = {
- /* For compatibility with older patches
- * use KEXEC_ARCH_DEFAULT instead of KEXEC_ARCH_X86_64 here.
- */
- { "x86_64", KEXEC_ARCH_DEFAULT },
+ { "x86_64", KEXEC_ARCH_X86_64 },
{ NULL, 0 },
};
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^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] - make /proc/vmcore accesable on x86_64
2010-10-29 7:54 ` [PATCH] " Jiri Olsa
@ 2010-10-31 1:16 ` Simon Horman
0 siblings, 0 replies; 5+ messages in thread
From: Simon Horman @ 2010-10-31 1:16 UTC (permalink / raw)
To: Jiri Olsa; +Cc: kexec
On Fri, Oct 29, 2010 at 09:54:25AM +0200, Jiri Olsa wrote:
> On Thu, Oct 28, 2010 at 09:16:27PM +0900, Simon Horman wrote:
> > On Fri, Oct 22, 2010 at 10:54:12AM +0200, Simon Horman wrote:
> > > On Tue, Oct 19, 2010 at 05:06:30PM +0200, Jiri Olsa wrote:
>
> SNIP
>
> > > > My goal is to share data within the host and kexec-ed kernel,
> > > > so I'd like to use the /proc/vmcore for that.. any other
> > > > ideas are welcome :)
> > >
> > > This approach seems reasonable to me.
> > > I'll push it if a I don't hear any objections
> > > in the near future.
> >
> > Hi Jiru,
> >
> > could you please submit this as a formal patch with a signed-off-by line?
>
> sure, it's attached
Thanks, applied.
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^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-10-31 1:17 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-10-19 15:06 [PATCH,RFC] - make /proc/vmcore accesable on x86_64 Jiri Olsa
2010-10-22 8:54 ` Simon Horman
2010-10-28 12:16 ` Simon Horman
2010-10-29 7:54 ` [PATCH] " Jiri Olsa
2010-10-31 1:16 ` Simon Horman
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