From: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: Sai Praneeth
<sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>,
Ricardo Neri
<ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Matt Fleming
<matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>,
Ard Biesheuvel
<ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
Ravi Shankar
<ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Subject: [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec
Date: Thu, 11 May 2017 12:20:33 -0700 [thread overview]
Message-ID: <1494530433-19503-1-git-send-email-sai.praneeth.prakhya@intel.com> (raw)
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
next reply other threads:[~2017-05-11 19:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-11 19:20 Sai Praneeth Prakhya [this message]
2017-05-15 14:27 ` [PATCH V2] x86/efi: Add EFI_PGT_DUMP support for x86_32, kexec Matt Fleming
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