linux-xiaomi-chiron

Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices: OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)

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Fabiano Rosas 5d7d6dac8f KVM: PPC: Book3S HV: Fix copy_tofrom_guest routines The __kvmhv_copy_tofrom_guest_radix function was introduced along with nested HV guest support. It uses the platform's Radix MMU quadrants to provide a nested hypervisor with fast access to its nested guests memory (H_COPY_TOFROM_GUEST hypercall). It has also since been added as a fast path for the kvmppc_ld/st routines which are used during instruction emulation. The commit `def0bfdbd6` ("powerpc: use probe_user_read() and probe_user_write()") changed the low level copy function from raw_copy_from_user to probe_user_read, which adds a check to access_ok. In powerpc that is: static inline bool __access_ok(unsigned long addr, unsigned long size) { return addr < TASK_SIZE_MAX && size <= TASK_SIZE_MAX - addr; } and TASK_SIZE_MAX is 0x0010000000000000UL for 64-bit, which means that setting the two MSBs of the effective address (which correspond to the quadrant) now cause access_ok to reject the access. This was not caught earlier because the most common code path via kvmppc_ld/st contains a fallback (kvm_read_guest) that is likely to succeed for L1 guests. For nested guests there is no fallback. Another issue is that probe_user_read (now __copy_from_user_nofault) does not return the number of bytes not copied in case of failure, so the destination memory is not being cleared anymore in kvmhv_copy_from_guest_radix: ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n); if (ret > 0) <-- always false! memset(to + (n - ret), 0, ret); This patch fixes both issues by skipping access_ok and open-coding the low level __copy_to/from_user_inatomic. Fixes: `def0bfdbd6` ("powerpc: use probe_user_read() and probe_user_write()") Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210805212616.2641017-2-farosas@linux.ibm.com		2021-08-24 23:14:06 +10:00
arch	KVM: PPC: Book3S HV: Fix copy_tofrom_guest routines	2021-08-24 23:14:06 +10:00
block
certs
crypto
Documentation	Kbuild fixes for v5.14	2021-07-18 11:10:30 -07:00
drivers	ARM: SoC fixes for v5.14	2021-07-17 15:58:24 -07:00
fs	Fixes for 5.14-rc:	2021-07-18 11:27:25 -07:00
include	ARM: SoC fixes for v5.14	2021-07-17 15:58:24 -07:00
init	Revert "mm/slub: use stackdepot to save stack trace in objects"	2021-07-17 13:27:00 -07:00
ipc
kernel	tracing: Fix the histogram logic from possibly crashing the kernel	2021-07-17 12:36:51 -07:00
lib
LICENSES
mm	Revert "mm/slub: use stackdepot to save stack trace in objects"	2021-07-17 13:27:00 -07:00
net
samples
scripts	Kbuild fixes for v5.14	2021-07-18 11:10:30 -07:00
security
sound
tools	perf tools fixes for v5.14: 1st batch	2021-07-18 12:20:27 -07:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile	Linux 5.14-rc2	2021-07-18 14:13:49 -07:00
README

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.