Jammy update: v5.15.28 upstream stable release

    SRU Justification

    Impact:
       The upstream process for stable tree updates is quite similar
       in scope to the Ubuntu SRU process, e.g., each patch has to
       demonstrably fix a bug, and each patch is vetted by upstream
       by originating either directly from a mainline/stable Linux tree or
       a minimally backported form of that patch. The following upstream
       stable patches should be included in the Ubuntu kernel:

       v5.15.28 upstream stable release
       from git://git.kernel.org/

Linux 5.15.28
Revert "ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE"
xen/netfront: react properly to failing gnttab_end_foreign_access_ref()
xen/gnttab: fix gnttab_end_foreign_access() without page specified
xen/pvcalls: use alloc/free_pages_exact()
xen/9p: use alloc/free_pages_exact()
xen: remove gnttab_query_foreign_access()
xen/gntalloc: don't use gnttab_query_foreign_access()
xen/scsifront: don't use gnttab_query_foreign_access() for mapped status
xen/netfront: don't use gnttab_query_foreign_access() for mapped status
xen/blkfront: don't use gnttab_query_foreign_access() for mapped status
xen/grant-table: add gnttab_try_end_foreign_access()
xen/xenbus: don't let xenbus_grant_ring() remove grants in error case
ARM: fix build warning in proc-v7-bugs.c
arm64: Do not include __READ_ONCE() block in assembly files
ARM: Do not use NOCROSSREFS directive with ld.lld
ARM: fix co-processor register typo
ARM: fix build error when BPF_SYSCALL is disabled
arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting
arm64: Use the clearbhb instruction in mitigations
KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated
arm64: Mitigate spectre style branch history side channels
arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2
arm64: Add percpu vectors for EL1
arm64: entry: Add macro for reading symbol addresses from the trampoline
arm64: entry: Add vectors that have the bhb mitigation sequences
arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations
arm64: entry: Allow the trampoline text to occupy multiple pages
arm64: entry: Make the kpti trampoline's kpti sequence optional
arm64: entry: Move trampoline macros out of ifdef'd section
arm64: entry: Don't assume tramp_vectors is the start of the vectors
arm64: entry: Allow tramp_alias to access symbols after the 4K boundary
arm64: entry: Move the trampoline data page before the text page
arm64: entry: Free up another register on kpti's tramp_exit path
arm64: entry: Make the trampoline cleanup optional
KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A
arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit
arm64: entry.S: Add ventry overflow sanity checks
arm64: cpufeature: add HWCAP for FEAT_RPRES
arm64: cpufeature: add HWCAP for FEAT_AFP
arm64: add ID_AA64ISAR2_EL1 sys register
arm64: Add Cortex-X2 CPU part definition
arm64: Add HWCAP for self-synchronising virtual counter
arm64: Add Neoverse-N2, Cortex-A710 CPU part definition
ARM: include unprivileged BPF status in Spectre V2 reporting
ARM: Spectre-BHB workaround
ARM: use LOADADDR() to get load address of sections
ARM: early traps initialisation
ARM: report Spectre v2 status through sysfs
x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT
x86/speculation: Warn about Spectre v2 LFENCE mitigation
x86/speculation: Update link to AMD speculation whitepaper
x86/speculation: Use generic retpoline by default on AMD
x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting
Documentation/hw-vuln: Update spectre doc
x86/speculation: Add eIBRS + Retpoline options
x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE
x86,bugs: Unconditionally allow spectre_v2=retpoline,amd
slip: fix macro redefine warning