In /proc/iomem, sub-regions should be inserted after their parent,
otherwise the insertion of parent resource fails. But after generic
crashkernel reservation applied, in both RISC-V and ARM64 (LoongArch
will also use generic reservation later on), crashkernel resources are
inserted before their parent, which causes the parent disappear in
/proc/iomem. So we defer the insertion of crashkernel resources to an
early_initcall().
1, Without 'crashkernel' parameter:
100d0100-100d01ff : LOON0001:00
100d0100-100d01ff : LOON0001:00 LOON0001:00
100e0000-100e0bff : LOON0002:00
100e0000-100e0bff : LOON0002:00 LOON0002:00
1fe001e0-1fe001e7 : serial
90400000-fa17ffff : System RAM
f6220000-f622ffff : Reserved
f9ee0000-f9ee3fff : Reserved
fa120000-fa17ffff : Reserved
fa190000-fe0bffff : System RAM
fa190000-fa1bffff : Reserved
fe4e0000-47fffffff : System RAM
43c000000-441ffffff : Reserved
47ff98000-47ffa3fff : Reserved
47ffa4000-47ffa7fff : Reserved
47ffa8000-47ffabfff : Reserved
47ffac000-47ffaffff : Reserved
47ffb0000-47ffb3fff : Reserved
2, With 'crashkernel' parameter, before this patch:
100d0100-100d01ff : LOON0001:00
100d0100-100d01ff : LOON0001:00 LOON0001:00
100e0000-100e0bff : LOON0002:00
100e0000-100e0bff : LOON0002:00 LOON0002:00
1fe001e0-1fe001e7 : serial
e6200000-f61fffff : Crash kernel
fa190000-fe0bffff : System RAM
fa190000-fa1bffff : Reserved
fe4e0000-47fffffff : System RAM
43c000000-441ffffff : Reserved
47ff98000-47ffa3fff : Reserved
47ffa4000-47ffa7fff : Reserved
47ffa8000-47ffabfff : Reserved
47ffac000-47ffaffff : Reserved
47ffb0000-47ffb3fff : Reserved
3, With 'crashkernel' parameter, after this patch:
100d0100-100d01ff : LOON0001:00
100d0100-100d01ff : LOON0001:00 LOON0001:00
100e0000-100e0bff : LOON0002:00
100e0000-100e0bff : LOON0002:00 LOON0002:00
1fe001e0-1fe001e7 : serial
90400000-fa17ffff : System RAM
e6200000-f61fffff : Crash kernel
f6220000-f622ffff : Reserved
f9ee0000-f9ee3fff : Reserved
fa120000-fa17ffff : Reserved
fa190000-fe0bffff : System RAM
fa190000-fa1bffff : Reserved
fe4e0000-47fffffff : System RAM
43c000000-441ffffff : Reserved
47ff98000-47ffa3fff : Reserved
47ffa4000-47ffa7fff : Reserved
47ffa8000-47ffabfff : Reserved
47ffac000-47ffaffff : Reserved
47ffb0000-47ffb3fff : Reserved
Signed-off-by: Huacai Chen <[email protected]>
---
kernel/crash_core.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index d4313b53837e..755d8d4ef5b0 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -377,7 +377,6 @@ static int __init reserve_crashkernel_low(unsigned long long low_size)
crashk_low_res.start = low_base;
crashk_low_res.end = low_base + low_size - 1;
- insert_resource(&iomem_resource, &crashk_low_res);
#endif
return 0;
}
@@ -459,8 +458,19 @@ void __init reserve_crashkernel_generic(char *cmdline,
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
- insert_resource(&iomem_resource, &crashk_res);
}
+
+static __init int insert_crashkernel_resources(void)
+{
+ if (crashk_res.start < crashk_res.end)
+ insert_resource(&iomem_resource, &crashk_res);
+
+ if (crashk_low_res.start < crashk_low_res.end)
+ insert_resource(&iomem_resource, &crashk_low_res);
+
+ return 0;
+}
+early_initcall(insert_crashkernel_resources);
#endif
int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
--
2.39.3
Huacai,
On 12/29/23 at 04:02pm, Huacai Chen wrote:
> In /proc/iomem, sub-regions should be inserted after their parent,
> otherwise the insertion of parent resource fails. But after generic
> crashkernel reservation applied, in both RISC-V and ARM64 (LoongArch
> will also use generic reservation later on), crashkernel resources are
> inserted before their parent, which causes the parent disappear in
> /proc/iomem. So we defer the insertion of crashkernel resources to an
> early_initcall().
>
> 1, Without 'crashkernel' parameter:
>
> 100d0100-100d01ff : LOON0001:00
> 100d0100-100d01ff : LOON0001:00 LOON0001:00
> 100e0000-100e0bff : LOON0002:00
> 100e0000-100e0bff : LOON0002:00 LOON0002:00
> 1fe001e0-1fe001e7 : serial
> 90400000-fa17ffff : System RAM
> f6220000-f622ffff : Reserved
> f9ee0000-f9ee3fff : Reserved
> fa120000-fa17ffff : Reserved
> fa190000-fe0bffff : System RAM
> fa190000-fa1bffff : Reserved
> fe4e0000-47fffffff : System RAM
> 43c000000-441ffffff : Reserved
> 47ff98000-47ffa3fff : Reserved
> 47ffa4000-47ffa7fff : Reserved
> 47ffa8000-47ffabfff : Reserved
> 47ffac000-47ffaffff : Reserved
> 47ffb0000-47ffb3fff : Reserved
>
> 2, With 'crashkernel' parameter, before this patch:
>
> 100d0100-100d01ff : LOON0001:00
> 100d0100-100d01ff : LOON0001:00 LOON0001:00
> 100e0000-100e0bff : LOON0002:00
> 100e0000-100e0bff : LOON0002:00 LOON0002:00
> 1fe001e0-1fe001e7 : serial
> e6200000-f61fffff : Crash kernel
> fa190000-fe0bffff : System RAM
> fa190000-fa1bffff : Reserved
> fe4e0000-47fffffff : System RAM
> 43c000000-441ffffff : Reserved
> 47ff98000-47ffa3fff : Reserved
> 47ffa4000-47ffa7fff : Reserved
> 47ffa8000-47ffabfff : Reserved
> 47ffac000-47ffaffff : Reserved
> 47ffb0000-47ffb3fff : Reserved
>
> 3, With 'crashkernel' parameter, after this patch:
>
> 100d0100-100d01ff : LOON0001:00
> 100d0100-100d01ff : LOON0001:00 LOON0001:00
> 100e0000-100e0bff : LOON0002:00
> 100e0000-100e0bff : LOON0002:00 LOON0002:00
> 1fe001e0-1fe001e7 : serial
> 90400000-fa17ffff : System RAM
> e6200000-f61fffff : Crash kernel
> f6220000-f622ffff : Reserved
> f9ee0000-f9ee3fff : Reserved
> fa120000-fa17ffff : Reserved
> fa190000-fe0bffff : System RAM
> fa190000-fa1bffff : Reserved
> fe4e0000-47fffffff : System RAM
> 43c000000-441ffffff : Reserved
> 47ff98000-47ffa3fff : Reserved
> 47ffa4000-47ffa7fff : Reserved
> 47ffa8000-47ffabfff : Reserved
> 47ffac000-47ffaffff : Reserved
> 47ffb0000-47ffb3fff : Reserved
This looks like a great catch. I am curious where arm64 and loongarch
insert the system RAM range into iomem before crashk_res and
crashk_low_res. On x86, it should be done by pci or acpi init which is
earlier than crashkernel parsing and inserting into iomem, just went\
through codes, haven't adding debugging code to print.
>
> Signed-off-by: Huacai Chen <[email protected]>
> ---
> kernel/crash_core.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index d4313b53837e..755d8d4ef5b0 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -377,7 +377,6 @@ static int __init reserve_crashkernel_low(unsigned long long low_size)
>
> crashk_low_res.start = low_base;
> crashk_low_res.end = low_base + low_size - 1;
> - insert_resource(&iomem_resource, &crashk_low_res);
> #endif
> return 0;
> }
> @@ -459,8 +458,19 @@ void __init reserve_crashkernel_generic(char *cmdline,
>
> crashk_res.start = crash_base;
> crashk_res.end = crash_base + crash_size - 1;
> - insert_resource(&iomem_resource, &crashk_res);
> }
> +
> +static __init int insert_crashkernel_resources(void)
> +{
> + if (crashk_res.start < crashk_res.end)
> + insert_resource(&iomem_resource, &crashk_res);
> +
> + if (crashk_low_res.start < crashk_low_res.end)
> + insert_resource(&iomem_resource, &crashk_low_res);
> +
> + return 0;
> +}
> +early_initcall(insert_crashkernel_resources);
> #endif
>
> int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
> --
> 2.39.3
>
>
> _______________________________________________
> kexec mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/kexec
>
On Fri, 29 Dec 2023 16:02:13 +0800 Huacai Chen <[email protected]> wrote:
> In /proc/iomem, sub-regions should be inserted after their parent,
> otherwise the insertion of parent resource fails. But after generic
> crashkernel reservation applied, in both RISC-V and ARM64 (LoongArch
> will also use generic reservation later on), crashkernel resources are
> inserted before their parent, which causes the parent disappear in
> /proc/iomem. So we defer the insertion of crashkernel resources to an
> early_initcall().
>
> ...
>
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -377,7 +377,6 @@ static int __init reserve_crashkernel_low(unsigned long long low_size)
>
> crashk_low_res.start = low_base;
> crashk_low_res.end = low_base + low_size - 1;
> - insert_resource(&iomem_resource, &crashk_low_res);
> #endif
> return 0;
> }
> @@ -459,8 +458,19 @@ void __init reserve_crashkernel_generic(char *cmdline,
>
> crashk_res.start = crash_base;
> crashk_res.end = crash_base + crash_size - 1;
> - insert_resource(&iomem_resource, &crashk_res);
> }
> +
> +static __init int insert_crashkernel_resources(void)
> +{
> + if (crashk_res.start < crashk_res.end)
> + insert_resource(&iomem_resource, &crashk_res);
> +
> + if (crashk_low_res.start < crashk_low_res.end)
> + insert_resource(&iomem_resource, &crashk_low_res);
> +
> + return 0;
> +}
> +early_initcall(insert_crashkernel_resources);
> #endif
>
> int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
I'm thinking
Fixes: 0ab97169aa0 ("crash_core: add generic function to do reservation").
Also, is this a regression? Were earlier kernels OK?
On 01/05/24 at 08:49am, Andrew Morton wrote:
> On Fri, 29 Dec 2023 16:02:13 +0800 Huacai Chen <[email protected]> wrote:
>
> > In /proc/iomem, sub-regions should be inserted after their parent,
> > otherwise the insertion of parent resource fails. But after generic
> > crashkernel reservation applied, in both RISC-V and ARM64 (LoongArch
> > will also use generic reservation later on), crashkernel resources are
> > inserted before their parent, which causes the parent disappear in
> > /proc/iomem. So we defer the insertion of crashkernel resources to an
> > early_initcall().
> >
> > ...
> >
> > --- a/kernel/crash_core.c
> > +++ b/kernel/crash_core.c
> > @@ -377,7 +377,6 @@ static int __init reserve_crashkernel_low(unsigned long long low_size)
> >
> > crashk_low_res.start = low_base;
> > crashk_low_res.end = low_base + low_size - 1;
> > - insert_resource(&iomem_resource, &crashk_low_res);
> > #endif
> > return 0;
> > }
> > @@ -459,8 +458,19 @@ void __init reserve_crashkernel_generic(char *cmdline,
> >
> > crashk_res.start = crash_base;
> > crashk_res.end = crash_base + crash_size - 1;
> > - insert_resource(&iomem_resource, &crashk_res);
> > }
> > +
> > +static __init int insert_crashkernel_resources(void)
> > +{
> > + if (crashk_res.start < crashk_res.end)
> > + insert_resource(&iomem_resource, &crashk_res);
> > +
> > + if (crashk_low_res.start < crashk_low_res.end)
> > + insert_resource(&iomem_resource, &crashk_low_res);
> > +
> > + return 0;
> > +}
> > +early_initcall(insert_crashkernel_resources);
> > #endif
> >
> > int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
>
> I'm thinking
>
> Fixes: 0ab97169aa0 ("crash_core: add generic function to do reservation").
Yes.
>
> Also, is this a regression? Were earlier kernels OK?
It's a regression, will impact arm64 in v6.6 kernel. Add below too?
Cc: <[email protected]> # 6.6.x