Pull x86 fixes from Borislav Petkov: - Add the respective UP last level cache mask accessors in order not to cause segfaults when lscpu accesses their representation in sysfs - Fix for a race in the alternatives batch patching machinery when kprobes are set * tag 'x86_urgent_for_v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cacheinfo: Add a cpu_llc_shared_mask() UP variant x86/alternative: Fix race in try_get_desc()
I encountered some occasional crashes of poke_int3_handler() when
kprobes are set, while accessing desc->vec.
The text poke mechanism claims to have an RCU-like behavior, but it
does not appear that there is any quiescent state to ensure that
nobody holds reference to desc. As a result, the following race
appears to be possible, which can lead to memory corruption.
CPU0 CPU1
---- ----
text_poke_bp_batch()
-> smp_store_release(&bp_desc, &desc)
[ notice that desc is on
the stack ]
poke_int3_handler()
[ int3 might be kprobe's
so sync events are do not
help ]
-> try_get_desc(descp=&bp_desc)
desc = __READ_ONCE(bp_desc)
if (!desc) [false, success]
WRITE_ONCE(bp_desc, NULL);
atomic_dec_and_test(&desc.refs)
[ success, desc space on the stack
is being reused and might have
non-zero value. ]
arch_atomic_inc_not_zero(&desc->refs)
[ might succeed since desc points to
stack memory that was freed and might
be reused. ]
Fix this issue with small backportable patch. Instead of trying to
make RCU-like behavior for bp_desc, just eliminate the unnecessary
level of indirection of bp_desc, and hold the whole descriptor as a
global. Anyhow, there is only a single descriptor at any given
moment.
Fixes: 1f676247f36a4 ("x86/alternatives: Implement a better poke_int3_handler() completion scheme")
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@kernel.org
Link: https://lkml.kernel.org/r/20220920224743.3089-1-namit@vmware.com
Pull x86 fixes from Dave Hansen: - A performance fix for recent large AMD systems that avoids an ancient cpu idle hardware workaround - A new Intel model number. Folks like these upstream as soon as possible so that each developer doing feature development doesn't need to carry their own #define - SGX fixes for a userspace crash and a rare kernel warning * tag 'x86_urgent_for_v6.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ACPI: processor idle: Practically limit "Dummy wait" workaround to old Intel systems x86/sgx: Handle VA page allocation failure for EAUG on PF. x86/sgx: Do not fail on incomplete sanitization on premature stop of ksgxd x86/cpu: Add CPU model numbers for Meteor Lake
VM_FAULT_NOPAGE is expected behaviour for -EBUSY failure path, when
augmenting a page, as this means that the reclaimer thread has been
triggered, and the intention is just to round-trip in ring-3, and
retry with a new page fault.
Fixes: 5a90d2c3f5ef ("x86/sgx: Support adding of pages to an initialized enclave")
Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Vijay Dhanraj <vijay.dhanraj@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20220906000221.34286-3-jarkko@kernel.org
Unsanitized pages trigger WARN_ON() unconditionally, which can panic the
whole computer, if /proc/sys/kernel/panic_on_warn is set.
In sgx_init(), if misc_register() fails or misc_register() succeeds but
neither sgx_drv_init() nor sgx_vepc_init() succeeds, then ksgxd will be
prematurely stopped. This may leave unsanitized pages, which will result a
false warning.
Refine __sgx_sanitize_pages() to return:
1. Zero when the sanitization process is complete or ksgxd has been
requested to stop.
2. The number of unsanitized pages otherwise.
Fixes: 51ab30eb2ad4 ("x86/sgx: Replace section->init_laundry_list with sgx_dirty_page_list")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-sgx/20220825051827.246698-1-jarkko@kernel.org/T/#u
Link: https://lkml.kernel.org/r/20220906000221.34286-2-jarkko@kernel.org
Remove the CONFIG_PREEMPT_RT symbol from the ifdef around do_softirq_own_stack() and move it to Kconfig instead. Enable softirq stacks based on SOFTIRQ_ON_OWN_STACK which depends on HAVE_SOFTIRQ_ON_OWN_STACK and its default value is set to !PREEMPT_RT. This ensures that softirq stacks are not used on PREEMPT_RT and avoids a 'select' statement on an option which has a 'depends' statement. Link: https://lore.kernel.org/YvN5E%2FPrHfUhggr7@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull misc x86 fixes from Ingo Molnar: - Fix PAT on Xen, which caused i915 driver failures - Fix compat INT 80 entry crash on Xen PV guests - Fix 'MMIO Stale Data' mitigation status reporting on older Intel CPUs - Fix RSB stuffing regressions - Fix ORC unwinding on ftrace trampolines - Add Intel Raptor Lake CPU model number - Fix (work around) a SEV-SNP bootloader bug providing bogus values in boot_params->cc_blob_address, by ignoring the value on !SEV-SNP bootups. - Fix SEV-SNP early boot failure - Fix the objtool list of noreturn functions and annotate snp_abort(), which bug confused objtool on gcc-12. - Fix the documentation for retbleed * tag 'x86-urgent-2022-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation/ABI: Mention retbleed vulnerability info file for sysfs x86/sev: Mark snp_abort() noreturn x86/sev: Don't use cc_platform_has() for early SEV-SNP calls x86/boot: Don't propagate uninitialized boot_params->cc_blob_address x86/cpu: Add new Raptor Lake CPU model number x86/unwind/orc: Unwind ftrace trampolines with correct ORC entry x86/nospec: Fix i386 RSB stuffing x86/nospec: Unwreck the RSB stuffing x86/bugs: Add "unknown" reporting for MMIO Stale Data x86/entry: Fix entry_INT80_compat for Xen PV guests x86/PAT: Have pat_enabled() properly reflect state when running on Xen
Mark both the function prototype and definition as noreturn in order to prevent the compiler from doing transformations which confuse objtool like so: vmlinux.o: warning: objtool: sme_enable+0x71: unreachable instruction This triggers with gcc-12. Add it and sev_es_terminate() to the objtool noreturn tracking array too. Sort it while at it. Suggested-by: Michael Matz <matz@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20220824152420.20547-1-bp@alien8.de
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/
Pull x86 kprobes fix from Ingo Molnar: "Fix a kprobes bug in JNG/JNLE emulation when a kprobe is installed at such instructions, possibly resulting in incorrect execution (the wrong branch taken)" * tag 'perf-urgent-2022-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kprobes: Fix JNG/JNLE emulation