linux-stable.git/include/linux/efi.h, branch v3.14.78

efi: Make efivarfs entries immutable by default

2016-03-16T15:42:21+00:00

commit ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 upstream.

"rm -rf" is bricking some peoples' laptops because of variables being
used to store non-reinitializable firmware driver data that's required
to POST the hardware.

These are 100% bugs, and they need to be fixed, but in the mean time it
shouldn't be easy to *accidentally* brick machines.

We have to have delete working, and picking which variables do and don't
work for deletion is quite intractable, so instead make everything
immutable by default (except for a whitelist), and make tools that
aren't quite so broad-spectrum unset the immutable flag.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Make our variable validation list include the guid

2016-03-16T15:42:21+00:00

commit 8282f5d9c17fe15a9e658c06e3f343efae1a2a2f upstream.

All the variables in this list so far are defined to be in the global
namespace in the UEFI spec, so this just further ensures we're
validating the variables we think we are.

Including the guid for entries will become more important in future
patches when we decide whether or not to allow deletion of variables
based on presence in this list.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Do variable name validation tests in utf8

2016-03-16T15:42:20+00:00

commit 3dcb1f55dfc7631695e69df4a0d589ce5274bd07 upstream.

Actually translate from ucs2 to utf8 before doing the test, and then
test against our other utf8 data, instead of fudging it.

Signed-off-by: Peter Jones 
Acked-by: Matthew Garrett 
Tested-by: Lee, Chun-Yi 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'v3.13-rc7' into x86/efi-kexec to resolve conflicts

2014-01-05T11:34:29+00:00

Conflicts:
	arch/x86/platform/efi/efi.c
	drivers/firmware/efi/Kconfig

Signed-off-by: Ingo Molnar

efi: Export EFI runtime memory mapping to sysfs

2013-12-21T15:29:36+00:00

kexec kernel will need exactly same mapping for EFI runtime memory
ranges. Thus here export the runtime ranges mapping to sysfs,
kexec-tools will assemble them and pass to 2nd kernel via setup_data.

Introducing a new directory /sys/firmware/efi/runtime-map just like
/sys/firmware/memmap. Containing below attribute in each file of that
directory:

attribute  num_pages  phys_addr  type  virt_addr

Signed-off-by: Dave Young 
Tested-by: Toshi Kani 
Signed-off-by: Matt Fleming

efi: Export more EFI table variables to sysfs

2013-12-21T15:29:36+00:00

Export fw_vendor, runtime and config table physical addresses to
/sys/firmware/efi/{fw_vendor,runtime,config_table} because kexec kernels
need them.

From EFI spec these 3 variables will be updated to virtual address after
entering virtual mode. But kernel startup code will need the physical
address.

Signed-off-by: Dave Young 
Tested-by: Toshi Kani 
Signed-off-by: Matt Fleming

efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed

2013-11-28T20:16:55+00:00

Currently, when mounting pstore file system, a read callback of
efi_pstore driver runs mutiple times as below.

- In the first read callback, scan efivar_sysfs_list from head and pass
  a kmsg buffer of a entry to an upper pstore layer.
- In the second read callback, rescan efivar_sysfs_list from the entry
  and pass another kmsg buffer to it.
- Repeat the scan and pass until the end of efivar_sysfs_list.

In this process, an entry is read across the multiple read function
calls. To avoid race between the read and erasion, the whole process
above is protected by a spinlock, holding in open() and releasing in
close().

At the same time, kmemdup() is called to pass the buffer to pstore
filesystem during it. And then, it causes a following lockdep warning.

To make the dynamic memory allocation runnable without taking spinlock,
holding off a deletion of sysfs entry if it happens while scanning it
via efi_pstore, and deleting it after the scan is completed.

To implement it, this patch introduces two flags, scanning and deleting,
to efivar_entry.

On the code basis, it seems that all the scanning and deleting logic is
not needed because __efivars->lock are not dropped when reading from the
EFI variable store.

But, the scanning and deleting logic is still needed because an
efi-pstore and a pstore filesystem works as follows.

In case an entry(A) is found, the pointer is saved to psi->data.  And
efi_pstore_read() passes the entry(A) to a pstore filesystem by
releasing  __efivars->lock.

And then, the pstore filesystem calls efi_pstore_read() again and the
same entry(A), which is saved to psi->data, is used for resuming to scan
a sysfs-list.

So, to protect the entry(A), the logic is needed.

[    1.143710] ------------[ cut here ]------------
[    1.144058] WARNING: CPU: 1 PID: 1 at kernel/lockdep.c:2740 lockdep_trace_alloc+0x104/0x110()
[    1.144058] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
[    1.144058] Modules linked in:
[    1.144058] CPU: 1 PID: 1 Comm: systemd Not tainted 3.11.0-rc5 #2
[    1.144058]  0000000000000009 ffff8800797e9ae0 ffffffff816614a5 ffff8800797e9b28
[    1.144058]  ffff8800797e9b18 ffffffff8105510d 0000000000000080 0000000000000046
[    1.144058]  00000000000000d0 00000000000003af ffffffff81ccd0c0 ffff8800797e9b78
[    1.144058] Call Trace:
[    1.144058]  [] dump_stack+0x54/0x74
[    1.144058]  [] warn_slowpath_common+0x7d/0xa0
[    1.144058]  [] warn_slowpath_fmt+0x4c/0x50
[    1.144058]  [] ? vsscanf+0x57f/0x7b0
[    1.144058]  [] lockdep_trace_alloc+0x104/0x110
[    1.144058]  [] __kmalloc_track_caller+0x50/0x280
[    1.144058]  [] ? efi_pstore_read_func.part.1+0x12b/0x170
[    1.144058]  [] kmemdup+0x20/0x50
[    1.144058]  [] efi_pstore_read_func.part.1+0x12b/0x170
[    1.144058]  [] ? efi_pstore_read_func.part.1+0x170/0x170
[    1.144058]  [] efi_pstore_read_func+0xb4/0xe0
[    1.144058]  [] __efivar_entry_iter+0xfb/0x120
[    1.144058]  [] efi_pstore_read+0x3f/0x50
[    1.144058]  [] pstore_get_records+0x9a/0x150
[    1.158207]  [] ? selinux_d_instantiate+0x1c/0x20
[    1.158207]  [] ? parse_options+0x80/0x80
[    1.158207]  [] pstore_fill_super+0xa5/0xc0
[    1.158207]  [] mount_single+0xa2/0xd0
[    1.158207]  [] pstore_mount+0x18/0x20
[    1.158207]  [] mount_fs+0x39/0x1b0
[    1.158207]  [] ? __alloc_percpu+0x10/0x20
[    1.158207]  [] vfs_kern_mount+0x63/0xf0
[    1.158207]  [] do_mount+0x23e/0xa20
[    1.158207]  [] ? strndup_user+0x4b/0xf0
[    1.158207]  [] SyS_mount+0x83/0xc0
[    1.158207]  [] system_call_fastpath+0x16/0x1b
[    1.158207] ---[ end trace 61981bc62de9f6f4 ]---

Signed-off-by: Seiji Aguchi 
Tested-by: Madper Xie 
Cc: stable@kernel.org
Signed-off-by: Matt Fleming

x86/efi: Runtime services virtual mapping

2013-11-02T11:09:36+00:00

We map the EFI regions needed for runtime services non-contiguously,
with preserved alignment on virtual addresses starting from -4G down
for a total max space of 64G. This way, we provide for stable runtime
services addresses across kernels so that a kexec'd kernel can still use
them.

Thus, they're mapped in a separate pagetable so that we don't pollute
the kernel namespace.

Add an efi= kernel command line parameter for passing miscellaneous
options and chicken bits from the command line.

While at it, add a chicken bit called "efi=old_map" which can be used as
a fallback to the old runtime services mapping method in case there's
some b0rkage with a particular EFI implementation (haha, it is hard to
hold up the sarcasm here...).

Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt.

Signed-off-by: Borislav Petkov 
Signed-off-by: Matt Fleming

efi: Add proper definitions for some EFI function pointers.

2013-09-25T11:34:33+00:00

The x86/AMD64 EFI stubs must use a call wrapper to convert between
the Linux and EFI ABIs, so void pointers are sufficient.  For ARM,
the ABIs are compatible, so we can directly invoke the function
pointers.  The functions that are used by the ARM stub are updated
to match the EFI definitions.
Also add some EFI types used by EFI functions.

Signed-off-by: Roy Franz 
Acked-by: Mark Salter 
Reviewed-by: Grant Likely 
Signed-off-by: Matt Fleming

efi: x86: make efi_lookup_mapped_addr() a common function

2013-09-05T12:29:29+00:00

efi_lookup_mapped_addr() is a handy utility for other platforms than
x86. Move it from arch/x86 to drivers/firmware. Add memmap pointer
to global efi structure, and initialise it on x86.

Signed-off-by: Leif Lindholm 
Signed-off-by: Matt Fleming