Merge tag 'alpha-for-v7.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/lindholm/alpha

Pull alpha updates from Magnus Lindholm:
"This completes Alpha's conversion to GENERIC_ENTRY and enabl

Merge tag 'alpha-for-v7.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/lindholm/alpha

Pull alpha updates from Magnus Lindholm:
"This completes Alpha's conversion to GENERIC_ENTRY and enables a range
of kernel features through Kconfig updates, including UBSAN, gcov,
kmemleak, page-table checking, fast GUP and sparse IRQs.

It includes TLB and MMU context fixes prompted by glibc test-suite
failures, HugeTLB support for 64KB, 512KB and 4MB pages, and fixes for
poisoned-page faults and page-table checking.

Machine-check handling is improved on Tsunami platforms, with bounded
EV6 logout decoding, Clipper environmental event reporting and safer
firmware console-log scanning.

Other changes add self-extracting compressed kernels with support for
all kernel compression formats, Alpha-specific XZ tuning, perf
register and user-stack sampling, and Alpha support in the seccomp
selftests. The series also fixes user stack-pointer reporting and IRQ
entry ordering, adds 128-bit shift helpers, cleans up linker sections,
and updates Kconfig help"

* tag 'alpha-for-v7.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/lindholm/alpha: (57 commits)
alpha: add bounded Clipper console-log scanning
alpha: decode Clipper environmental events
alpha: decode and acknowledge Tsunami system machine checks
alpha: bound EV6 logout decoding by the processor area
alpha: describe the Tsunami system machine check frame
alpha: move Tsunami machine check handling to err_tsunami.c
alpha: fill in pc for software event samples
alpha: add HAVE_PERF_REGS and HAVE_PERF_USER_STACK_DUMP support
alpha: use user_stack_pointer() in KSTK_ESP() and dump_elf_thread()
alpha: stop storing the user stack pointer in pt_regs
alpha: fix stale user_stack_pointer()
selftests/seccomp: add Alpha support to seccomp_bpf
alpha: do not skip TLB shootdown IPIs for kthread-borrowed mms
alpha: do not clear remote MMU contexts in migrate_flush_tlb_page()
alpha: invalidate the local context in flush_icache_user_page()
alpha: invalidate the local context in flush_tlb_mm()
alpha: fix the local TLB invalidate in the UP flush_tlb_page()
alpha: fix the local TLB invalidate in flush_tlb_page()
alpha: invalidate the local context in flush_tlb_page()
alpha: only use a targeted tbi() when the target mm is really current
...

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alpha: add HAVE_PERF_REGS and HAVE_PERF_USER_STACK_DUMP support

Let perf sample registers and dump the user stack, which is what the
perf tool needs for --call-graph dwarf.

The register indices fol

alpha: add HAVE_PERF_REGS and HAVE_PERF_USER_STACK_DUMP support

Let perf sample registers and dump the user stack, which is what the
perf tool needs for --call-graph dwarf.

The register indices follow the hardware numbering, so r0-r30 map
directly to DWARF register numbers, with pc after them. r9-r15
are callee-saved and live in switch_stack rather than pt_regs, so they
cannot be sampled. Without r15 an unwinder cannot recover the CFA of a
first frame that uses $15 as its frame pointer.

sp is not in pt_regs either: for user frames it comes from
user_stack_pointer(), and for kernel frames (PERF_SAMPLE_REGS_INTR) it
is the end of the trap frame, as in stacktrace.c.

Software events such as context switches and tracepoints hand perf a
per-CPU pt_regs filled in by perf_fetch_caller_regs() instead of a
trap frame. It is not on the stack and has no room for sp, so report
sp as 0 there rather than the address of the per-CPU buffer.

Assisted-by: Claude:claude-opus-5-5
Acked-by: Ian Rogers <irogers@google.com>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Reviewed-by: Magnus Lindholm <linmag7@gmail.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>
Link: https://lore.kernel.org/r/20261018-alpha-perf-regs-v3-v3-4-52be85332c57@gmail.com
Signed-off-by: Magnus Lindholm <linmag7@gmail.com>

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