2017-06-22 10:52:22

by Daniel Kiper

[permalink] [raw]
Subject: [PATCH v2 0/2] xen/efi: Fixes

Hey,

Two small fixes (v2, minor cleanup) for Xen dom0 running on x86_64 EFI platforms.

I am CC-ing stable maintainers because similar stuff is needed for various
stable kernels too. Unfortunately, almost every version needs a bit different
set of fixes. So, please treat this email more as head up than real set of
patches for your kernel. If you wish to get Xen EFI stuff fixed just drop me
a line. Then I will prepare set of patches for your kernel (if needed).

Ard, Andrew, Ingo, thank you for looking at the patches.

Daniel

arch/x86/xen/efi.c | 45 ++++++++++++---------------------------------
drivers/firmware/efi/efi.c | 3 ++-
2 files changed, 14 insertions(+), 34 deletions(-)

Daniel Kiper (2):
efi: Process MEMATTR table only if EFI_MEMMAP
x86/xen/efi: Init only efi struct members used by Xen


2017-06-22 10:53:08

by Daniel Kiper

[permalink] [raw]
Subject: [PATCH v2 1/2] efi: Process MEMATTR table only if EFI_MEMMAP

Otherwise e.g. Xen dom0 on x86_64 EFI platforms crashes.

In theory we can check EFI_PARAVIRT too, however,
EFI_MEMMAP looks more generic and covers more cases.

Signed-off-by: Daniel Kiper <[email protected]>
Reviewed-by: Ard Biesheuvel <[email protected]>
---
drivers/firmware/efi/efi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index b372aad..045d6d3 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -528,7 +528,8 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
}
}

- efi_memattr_init();
+ if (efi_enabled(EFI_MEMMAP))
+ efi_memattr_init();

/* Parse the EFI Properties table if it exists */
if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {
--
1.7.10.4

2017-06-22 10:53:39

by Daniel Kiper

[permalink] [raw]
Subject: [PATCH v2 2/2] x86/xen/efi: Init only efi struct members used by Xen

Current approach, wholesale efi struct initialization from efi_xen, is not
good. Usually if new member is defined then it is properly initialized in
drivers/firmware/efi/efi.c but not in arch/x86/xen/efi.c. As I saw it happened
a few times until now. So, let's initialize only efi struct members used by
Xen to avoid such issues in the future.

Signed-off-by: Daniel Kiper <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
--
Align assignments to increase readability. Suggested by Ingo Molnar.
---
arch/x86/xen/efi.c | 45 ++++++++++++---------------------------------
1 file changed, 12 insertions(+), 33 deletions(-)

diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
index 30bb2e8..a18703b 100644
--- a/arch/x86/xen/efi.c
+++ b/arch/x86/xen/efi.c
@@ -54,38 +54,6 @@
.tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */
};

-static const struct efi efi_xen __initconst = {
- .systab = NULL, /* Initialized later. */
- .runtime_version = 0, /* Initialized later. */
- .mps = EFI_INVALID_TABLE_ADDR,
- .acpi = EFI_INVALID_TABLE_ADDR,
- .acpi20 = EFI_INVALID_TABLE_ADDR,
- .smbios = EFI_INVALID_TABLE_ADDR,
- .smbios3 = EFI_INVALID_TABLE_ADDR,
- .sal_systab = EFI_INVALID_TABLE_ADDR,
- .boot_info = EFI_INVALID_TABLE_ADDR,
- .hcdp = EFI_INVALID_TABLE_ADDR,
- .uga = EFI_INVALID_TABLE_ADDR,
- .uv_systab = EFI_INVALID_TABLE_ADDR,
- .fw_vendor = EFI_INVALID_TABLE_ADDR,
- .runtime = EFI_INVALID_TABLE_ADDR,
- .config_table = EFI_INVALID_TABLE_ADDR,
- .get_time = xen_efi_get_time,
- .set_time = xen_efi_set_time,
- .get_wakeup_time = xen_efi_get_wakeup_time,
- .set_wakeup_time = xen_efi_set_wakeup_time,
- .get_variable = xen_efi_get_variable,
- .get_next_variable = xen_efi_get_next_variable,
- .set_variable = xen_efi_set_variable,
- .query_variable_info = xen_efi_query_variable_info,
- .update_capsule = xen_efi_update_capsule,
- .query_capsule_caps = xen_efi_query_capsule_caps,
- .get_next_high_mono_count = xen_efi_get_next_high_mono_count,
- .reset_system = xen_efi_reset_system,
- .set_virtual_address_map = NULL, /* Not used under Xen. */
- .flags = 0 /* Initialized later. */
-};
-
static efi_system_table_t __init *xen_efi_probe(void)
{
struct xen_platform_op op = {
@@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)

/* Here we know that Xen runs on EFI platform. */

- efi = efi_xen;
+ efi.get_time = xen_efi_get_time;
+ efi.set_time = xen_efi_set_time;
+ efi.get_wakeup_time = xen_efi_get_wakeup_time;
+ efi.set_wakeup_time = xen_efi_set_wakeup_time;
+ efi.get_variable = xen_efi_get_variable;
+ efi.get_next_variable = xen_efi_get_next_variable;
+ efi.set_variable = xen_efi_set_variable;
+ efi.query_variable_info = xen_efi_query_variable_info;
+ efi.update_capsule = xen_efi_update_capsule;
+ efi.query_capsule_caps = xen_efi_query_capsule_caps;
+ efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
+ efi.reset_system = xen_efi_reset_system;

efi_systab_xen.tables = info->cfg.addr;
efi_systab_xen.nr_tables = info->cfg.nent;
--
1.7.10.4

2017-06-22 19:24:14

by Boris Ostrovsky

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] x86/xen/efi: Init only efi struct members used by Xen

On 06/22/2017 06:51 AM, Daniel Kiper wrote:
> Current approach, wholesale efi struct initialization from efi_xen, is not
> good. Usually if new member is defined then it is properly initialized in
> drivers/firmware/efi/efi.c but not in arch/x86/xen/efi.c. As I saw it happened
> a few times until now. So, let's initialize only efi struct members used by
> Xen to avoid such issues in the future.
>
> Signed-off-by: Daniel Kiper <[email protected]>
> Acked-by: Ard Biesheuvel <[email protected]>

Reviewed-by: Boris Ostrovsky <[email protected]>


Subject: [tip:efi/core] efi: Process the MEMATTR table only if EFI_MEMMAP is enabled

Commit-ID: 457ea3f7e97881f937136ce0ba1f29f82b9abdb0
Gitweb: http://git.kernel.org/tip/457ea3f7e97881f937136ce0ba1f29f82b9abdb0
Author: Daniel Kiper <[email protected]>
AuthorDate: Thu, 22 Jun 2017 12:51:36 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 23 Jun 2017 11:11:02 +0200

efi: Process the MEMATTR table only if EFI_MEMMAP is enabled

Otherwise e.g. Xen dom0 on x86_64 EFI platforms crashes.

In theory we can check EFI_PARAVIRT too, however,
EFI_MEMMAP looks more targeted and covers more cases.

Signed-off-by: Daniel Kiper <[email protected]>
Reviewed-by: Ard Biesheuvel <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
drivers/firmware/efi/efi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index b372aad..045d6d3 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -528,7 +528,8 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
}
}

- efi_memattr_init();
+ if (efi_enabled(EFI_MEMMAP))
+ efi_memattr_init();

/* Parse the EFI Properties table if it exists */
if (efi.properties_table != EFI_INVALID_TABLE_ADDR) {

Subject: [tip:efi/core] x86/xen/efi: Initialize only the EFI struct members used by Xen

Commit-ID: 6c64447ec58b0bac612732303f7ab04562124587
Gitweb: http://git.kernel.org/tip/6c64447ec58b0bac612732303f7ab04562124587
Author: Daniel Kiper <[email protected]>
AuthorDate: Thu, 22 Jun 2017 12:51:37 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 23 Jun 2017 11:11:03 +0200

x86/xen/efi: Initialize only the EFI struct members used by Xen

The current approach, which is the wholesale efi struct initialization from
a 'efi_xen' local template is not robust. Usually if new member is defined
then it is properly initialized in drivers/firmware/efi/efi.c, but not in
arch/x86/xen/efi.c.

The effect is that the Xen initialization clears any fields the generic code
might have set and the Xen code does not know about yet.

I saw this happen a few times, so let's initialize only the EFI struct members
used by Xen and maintain no local duplicate, to avoid such issues in the future.

Signed-off-by: Daniel Kiper <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
[ Clarified the changelog. ]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/xen/efi.c | 45 ++++++++++++---------------------------------
1 file changed, 12 insertions(+), 33 deletions(-)

diff --git a/arch/x86/xen/efi.c b/arch/x86/xen/efi.c
index 30bb2e8..a18703b 100644
--- a/arch/x86/xen/efi.c
+++ b/arch/x86/xen/efi.c
@@ -54,38 +54,6 @@ static efi_system_table_t efi_systab_xen __initdata = {
.tables = EFI_INVALID_TABLE_ADDR /* Initialized later. */
};

-static const struct efi efi_xen __initconst = {
- .systab = NULL, /* Initialized later. */
- .runtime_version = 0, /* Initialized later. */
- .mps = EFI_INVALID_TABLE_ADDR,
- .acpi = EFI_INVALID_TABLE_ADDR,
- .acpi20 = EFI_INVALID_TABLE_ADDR,
- .smbios = EFI_INVALID_TABLE_ADDR,
- .smbios3 = EFI_INVALID_TABLE_ADDR,
- .sal_systab = EFI_INVALID_TABLE_ADDR,
- .boot_info = EFI_INVALID_TABLE_ADDR,
- .hcdp = EFI_INVALID_TABLE_ADDR,
- .uga = EFI_INVALID_TABLE_ADDR,
- .uv_systab = EFI_INVALID_TABLE_ADDR,
- .fw_vendor = EFI_INVALID_TABLE_ADDR,
- .runtime = EFI_INVALID_TABLE_ADDR,
- .config_table = EFI_INVALID_TABLE_ADDR,
- .get_time = xen_efi_get_time,
- .set_time = xen_efi_set_time,
- .get_wakeup_time = xen_efi_get_wakeup_time,
- .set_wakeup_time = xen_efi_set_wakeup_time,
- .get_variable = xen_efi_get_variable,
- .get_next_variable = xen_efi_get_next_variable,
- .set_variable = xen_efi_set_variable,
- .query_variable_info = xen_efi_query_variable_info,
- .update_capsule = xen_efi_update_capsule,
- .query_capsule_caps = xen_efi_query_capsule_caps,
- .get_next_high_mono_count = xen_efi_get_next_high_mono_count,
- .reset_system = xen_efi_reset_system,
- .set_virtual_address_map = NULL, /* Not used under Xen. */
- .flags = 0 /* Initialized later. */
-};
-
static efi_system_table_t __init *xen_efi_probe(void)
{
struct xen_platform_op op = {
@@ -102,7 +70,18 @@ static efi_system_table_t __init *xen_efi_probe(void)

/* Here we know that Xen runs on EFI platform. */

- efi = efi_xen;
+ efi.get_time = xen_efi_get_time;
+ efi.set_time = xen_efi_set_time;
+ efi.get_wakeup_time = xen_efi_get_wakeup_time;
+ efi.set_wakeup_time = xen_efi_set_wakeup_time;
+ efi.get_variable = xen_efi_get_variable;
+ efi.get_next_variable = xen_efi_get_next_variable;
+ efi.set_variable = xen_efi_set_variable;
+ efi.query_variable_info = xen_efi_query_variable_info;
+ efi.update_capsule = xen_efi_update_capsule;
+ efi.query_capsule_caps = xen_efi_query_capsule_caps;
+ efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
+ efi.reset_system = xen_efi_reset_system;

efi_systab_xen.tables = info->cfg.addr;
efi_systab_xen.nr_tables = info->cfg.nent;