When running identity-mapped and depending on the kernel configuration,
it is possible that the compiler uses jump tables when generating code
for cc_platform_has().

This causes a boot failure because the jump table uses un-mapped kernel
virtual addresses, not identity-mapped addresses. This has been seen
with CONFIG_RETPOLINE=n.

Similar to sme_encrypt_kernel(), use an open-coded direct check for the
status of SNP rather than trying to eliminate the jump table. This
preserves any code optimization in cc_platform_has() that can be useful
post boot. It also limits the changes to SEV-specific files so that
future compiler features won't necessarily require possible build changes
just because they are not compatible with running identity-mapped.

[ bp: Massage commit message. ]

Fixes: 5e5ccff60a29 ("x86/sev: Add helper for validating pages in early enc attribute changes")
Reported-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 5.19.x
Link: https://lore.kernel.org/all/YqfabnTRxFSM+LoX@google.com/

In some cases, bootloaders will leave boot_params->cc_blob_address
uninitialized rather than zeroing it out. This field is only meant to be
set by the boot/compressed kernel in order to pass information to the
uncompressed kernel when SEV-SNP support is enabled.

Therefore, there are no cases where the bootloader-provided values
should be treated as anything other than garbage. Otherwise, the
uncompressed kernel may attempt to access this bogus address, leading to
a crash during early boot.

Normally, sanitize_boot_params() would be used to clear out such fields
but that happens too late: sev_enable() may have already initialized
it to a valid value that should not be zeroed out. Instead, have
sev_enable() zero it out unconditionally beforehand.

Also ensure this happens for !CONFIG_AMD_MEM_ENCRYPT as well by also
including this handling in the sev_enable() stub function.

[ bp: Massage commit message and comments. ]

Fixes: b190a043c49a ("x86/sev: Add SEV-SNP feature detection/setup")
Reported-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Reported-by: watnuss@gmx.de
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216387
Link: https://lore.kernel.org/r/20220823160734.89036-1-michael.roth@amd.com

Note1: Model 0xB7 already claimed the "no suffix" #define for a regular
client part, so add (yet another) suffix "S" to distinguish this new
part from the earlier one.

Note2: the RAPTORLAKE* and ALDERLAKE* processors are very similar from a
software enabling point of view. There are no known features that have
model-specific enabling and also differ between the two. In other words,
every single place that list *one* or more RAPTORLAKE* or ALDERLAKE*
processors should list all of them.

Note3: This is being merged before there is an in-tree user. Merging
this provides an "anchor" so that the different folks can update their
subsystems (like perf) in parallel to use this define and test it.

[ dhansen: add a note about why this has no in-tree users yet ]

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220823174819.223941-1-tony.luck@intel.com

When meeting ftrace trampolines in ORC unwinding, unwinder uses address
of ftrace_{regs_}call address to find the ORC entry, which gets next frame at
sp+176.

If there is an IRQ hitting at sub $0xa8,%rsp, the next frame should be
sp+8 instead of 176. It makes unwinder skip correct frame and throw
warnings such as "wrong direction" or "can't access registers", etc,
depending on the content of the incorrect frame address.

By adding the base address ftrace_{regs_}caller with the offset
*ip - ops->trampoline*, we can get the correct address to find the ORC entry.

Also change "caller" to "tramp_addr" to make variable name conform to
its content.

[ mingo: Clarified the changelog a bit. ]

Fixes: 6be7fa3c74d1 ("ftrace, orc, x86: Handle ftrace dynamically allocated trampolines")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220819084334.244016-1-chenzhongjin@huawei.com

Turns out that i386 doesn't unconditionally have LFENCE, as such the
loop in __FILL_RETURN_BUFFER isn't actually speculation safe on such
chips.

Fixes: ba6e31af2be9 ("x86/speculation: Add LFENCE to RSB fill sequence")
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yv9tj9vbQ9nNlXoY@worktop.programming.kicks-ass.net

Commit 2b1299322016 ("x86/speculation: Add RSB VM Exit protections")
made a right mess of the RSB stuffing, rewrite the whole thing to not
suck.

Thanks to Andrew for the enlightening comment about Post-Barrier RSB
things so we can make this code less magical.

Cc: stable@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YvuNdDWoUZSBjYcm@worktop.programming.kicks-ass.net

Older Intel CPUs that are not in the affected processor list for MMIO
Stale Data vulnerabilities currently report "Not affected" in sysfs,
which may not be correct. Vulnerability status for these older CPUs is
unknown.

Add known-not-affected CPUs to the whitelist. Report "unknown"
mitigation status for CPUs that are not in blacklist, whitelist and also
don't enumerate MSR ARCH_CAPABILITIES bits that reflect hardware
immunity to MMIO Stale Data vulnerabilities.

Mitigation is not deployed when the status is unknown.

[ bp: Massage, fixup. ]

Fixes: 8d50cdf8b834 ("x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data")
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/a932c154772f2121794a5f2eded1a11013114711.1657846269.git.pawan.kumar.gupta@linux.intel.com

Commit

c89191ce67ef ("x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS")

missed one use case of SWAPGS in entry_INT80_compat(). Removing of
the SWAPGS macro led to asm just using "swapgs", as it is accepting
instructions in capital letters, too.

This in turn leads to splats in Xen PV guests like:

[ 36.145223] general protection fault, maybe for address 0x2d: 0000 [#1] PREEMPT SMP NOPTI
[ 36.145794] CPU: 2 PID: 1847 Comm: ld-linux.so.2 Not tainted 5.19.1-1-default #1 \
openSUSE Tumbleweed f3b44bfb672cdb9f235aff53b57724eba8b9411b
[ 36.146608] Hardware name: HP ProLiant ML350p Gen8, BIOS P72 11/14/2013
[ 36.148126] RIP: e030:entry_INT80_compat+0x3/0xa3

Fix that by open coding this single instance of the SWAPGS macro.

Fixes: c89191ce67ef ("x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS")
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: <stable@vger.kernel.org> # 5.19
Link: https://lore.kernel.org/r/20220816071137.4893-1-jgross@suse.com

After commit ID in the Fixes: tag, pat_enabled() returns false (because
of PAT initialization being suppressed in the absence of MTRRs being
announced to be available).

This has become a problem: the i915 driver now fails to initialize when
running PV on Xen (i915_gem_object_pin_map() is where I located the
induced failure), and its error handling is flaky enough to (at least
sometimes) result in a hung system.

Yet even beyond that problem the keying of the use of WC mappings to
pat_enabled() (see arch_can_pci_mmap_wc()) means that in particular
graphics frame buffer accesses would have been quite a bit less optimal
than possible.

Arrange for the function to return true in such environments, without
undermining the rest of PAT MSR management logic considering PAT to be
disabled: specifically, no writes to the PAT MSR should occur.

For the new boolean to live in .init.data, init_cache_modes() also needs
moving to .init.text (where it could/should have lived already before).

[ bp: This is the "small fix" variant for stable. It'll get replaced
with a proper PAT and MTRR detection split upstream but that is too
involved for a stable backport.
- additional touchups to commit msg. Use cpu_feature_enabled(). ]

Fixes: bdd8b6c98239 ("drm/i915: replace X86_FEATURE_PAT with pat_enabled()")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/9385fa60-fa5d-f559-a137-6608408f88b0@suse.com

Radix tree header includes gfp.h for __GFP_BITS_SHIFT only. Now we
have gfp_types.h for this.

Fixes powerpc allmodconfig build:

In file included from include/linux/nodemask.h:97,
from include/linux/mmzone.h:17,
from include/linux/gfp.h:7,
from include/linux/radix-tree.h:12,
from include/linux/idr.h:15,
from include/linux/kernfs.h:12,
from include/linux/sysfs.h:16,
from include/linux/kobject.h:20,
from include/linux/pci.h:35,
from arch/powerpc/kernel/prom_init.c:24:
include/linux/random.h: In function 'add_latent_entropy':
>> include/linux/random.h:25:46: error: 'latent_entropy' undeclared (first use in this function); did you mean 'add_latent_entropy'?
25 | add_device_randomness((const void *)&latent_entropy, sizeof(latent_entropy));
| ^~~~~~~~~~~~~~
| add_latent_entropy
include/linux/random.h:25:46: note: each undeclared identifier is reported only once for each function it appears in

Reported-by: kernel test robot <lkp@intel.com>
CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull vfs lseek fix from Al Viro:
"Fix proc_reg_llseek() breakage. Always had been possible if somebody
left NULL ->proc_lseek, became a practical issue now"

* tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
take care to handle NULL ->proc_lseek()

Pull more xen updates from Juergen Gross:

- fix the handling of the "persistent grants" feature negotiation
between Xen blkfront and Xen blkback drivers

- a cleanup of xen.config and adding xen.config to Xen section in
MAINTAINERS

- support HVMOP_set_evtchn_upcall_vector, which is more compliant to
"normal" interrupt handling than the global callback used up to now

- further small cleanups

* tag 'for-linus-6.0-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
MAINTAINERS: add xen config fragments to XEN HYPERVISOR sections
xen: remove XEN_SCRUB_PAGES in xen.config
xen/pciback: Fix comment typo
xen/xenbus: fix return type in xenbus_file_read()
xen-blkfront: Apply 'feature_persistent' parameter when connect
xen-blkback: Apply 'feature_persistent' parameter when connect
xen-blkback: fix persistent grants negotiation
x86/xen: Add support for HVMOP_set_evtchn_upcall_vector

Easily done now, just by clearing FMODE_LSEEK in ->f_mode
during proc_reg_open() for such entries.

Fixes: 868941b14441 "fs: remove no_llseek"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>