* [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec
@ 2017-05-11 19:20 Sai Praneeth Prakhya
2017-05-15 14:27 ` Matt Fleming
0 siblings, 1 reply; 2+ messages in thread
From: Sai Praneeth Prakhya @ 2017-05-11 19:20 UTC (permalink / raw)
To: linux-efi-u79uwXL29TY76Z2rM5mHXA, linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Sai Praneeth, Borislav Petkov, Ricardo Neri, Matt Fleming,
Ard Biesheuvel, Ravi Shankar
From: Sai Praneeth <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
EFI_PGT_DUMP, as the name suggests dumps efi page tables to dmesg during
kernel boot. This feature is very useful while debugging page
faults/null pointer dereferences to efi related addresses. Presently,
this feature is limited only to x86_64, so let's extend it to other efi
configurations like kexec kernel, efi=old_map and to x86_32 as well.
This doesn't effect normal boot path because this config option should
be used only for debug purposes.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>
Cc: Ricardo Neri <ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Ravi Shankar <ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Changes since v1:
1. Call efi_dump_pagetable() only once from efi_enter_virtual_mode() -
as suggested by Boris
---
arch/x86/platform/efi/efi.c | 3 ++-
arch/x86/platform/efi/efi_32.c | 9 ++++++++-
arch/x86/platform/efi/efi_64.c | 5 ++++-
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 217dc166c649..87835c97611f 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -1011,7 +1011,6 @@ static void __init __efi_enter_virtual_mode(void)
* necessary relocation fixups for the new virtual addresses.
*/
efi_runtime_update_mappings();
- efi_dump_pagetable();
/* clean DUMMY object */
efi_delete_dummy_variable();
@@ -1026,6 +1025,8 @@ void __init efi_enter_virtual_mode(void)
kexec_enter_virtual_mode();
else
__efi_enter_virtual_mode();
+
+ efi_dump_pagetable();
}
/*
diff --git a/arch/x86/platform/efi/efi_32.c b/arch/x86/platform/efi/efi_32.c
index 9b1abcf6e7bb..9477653c78f8 100644
--- a/arch/x86/platform/efi/efi_32.c
+++ b/arch/x86/platform/efi/efi_32.c
@@ -44,7 +44,14 @@ int __init efi_alloc_page_tables(void)
}
void efi_sync_low_kernel_mappings(void) {}
-void __init efi_dump_pagetable(void) {}
+
+void __init efi_dump_pagetable(void)
+{
+#ifdef CONFIG_EFI_PGT_DUMP
+ ptdump_walk_pgd_level(NULL, swapper_pg_dir);
+#endif
+}
+
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
return 0;
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 76e1cd6b74dd..3bde2589fdb9 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -510,7 +510,10 @@ void __init efi_runtime_update_mappings(void)
void __init efi_dump_pagetable(void)
{
#ifdef CONFIG_EFI_PGT_DUMP
- ptdump_walk_pgd_level(NULL, efi_pgd);
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ ptdump_walk_pgd_level(NULL, swapper_pg_dir);
+ else
+ ptdump_walk_pgd_level(NULL, efi_pgd);
#endif
}
--
2.1.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec
2017-05-11 19:20 [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec Sai Praneeth Prakhya
@ 2017-05-15 14:27 ` Matt Fleming
0 siblings, 0 replies; 2+ messages in thread
From: Matt Fleming @ 2017-05-15 14:27 UTC (permalink / raw)
To: Sai Praneeth Prakhya
Cc: linux-efi, linux-kernel, Borislav Petkov, Ricardo Neri,
Ard Biesheuvel, Ravi Shankar
On Thu, 11 May, at 12:20:33PM, Sai Praneeth Prakhya wrote:
> From: Sai Praneeth <sai.praneeth.prakhya@intel.com>
>
> EFI_PGT_DUMP, as the name suggests dumps efi page tables to dmesg during
> kernel boot. This feature is very useful while debugging page
> faults/null pointer dereferences to efi related addresses. Presently,
> this feature is limited only to x86_64, so let's extend it to other efi
> configurations like kexec kernel, efi=old_map and to x86_32 as well.
> This doesn't effect normal boot path because this config option should
> be used only for debug purposes.
>
> Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: Ricardo Neri <ricardo.neri@intel.com>
> Cc: Matt Fleming <matt@codeblueprint.co.uk>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Ravi Shankar <ravi.v.shankar@intel.com>
>
> Changes since v1:
> 1. Call efi_dump_pagetable() only once from efi_enter_virtual_mode() -
> as suggested by Boris
>
> ---
> arch/x86/platform/efi/efi.c | 3 ++-
> arch/x86/platform/efi/efi_32.c | 9 ++++++++-
> arch/x86/platform/efi/efi_64.c | 5 ++++-
> 3 files changed, 14 insertions(+), 3 deletions(-)
Thanks Sai, applied.
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2017-05-11 19:20 [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec Sai Praneeth Prakhya
2017-05-15 14:27 ` Matt Fleming
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