Merge tag 'perf-tools-for-v7.3-2026-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "perf c2c:

   - Add 'function view' in perf c2c report TUI (switched by pressing
     'TAB' in the cacheline view) to organize samples around functions
     rather than cachelines in 3-level hierarchy:

	Level 1: Read-side function (sorted by estimated Cycles %)
	Level 2:   Contending writer functions (sorted by Store count)
	Level 3:     Shared cacheline addresses

     Users can navigate the entries and fold/unfold using 'e' key. An
     example output would look like below:

	Shared Data Functions Table     (19 entries, sorted on Cycles %)
	   Cycles    Store
	        %    count  Function / Contending function / Cacheline
	----------------------------------------------------------------------
	+  35.67%      876  + [k] cpupri_set
	+  24.31%      424  + [k] pull_rt_task
	-  16.53%      555  - [k] dequeue_pushable_task
	               145    - [k] pull_rt_task
	               145        0xff2d0082809da080
	               139    - [k] enqueue_pushable_task
	                70        0xff2d00a2071f9640
	                69        0xff2d0082809da000

  python module support:

   - Extend "perf" python module so that it can be fully functional. The
     goal is to run scripts directly, not by 'perf script' command. This
     would give better performance as well as more control to build
     standalone programs with UI.

   - Add LiveSession helper (perf_live.py) to enable live event
     collection directly from Python using perf.evlist and
     perf.parse_events.

  perf stat:

   - Add --hide-zero-events option to suppress zero-count events
   - Reject conflicting --field-separator and --json-output options
   - Fix duplicate event output with --for-each-cgroup

  perf sched latency:

   - Add -H/--histogram and --hist-mode (log|linear) options to show
     scheduler wait latency histograms
   - Add --time option to filter analysis by time span in 'perf sched
     latency'

  ARM CoreSight:

   - Synthesize callchains for instruction samples from CoreSight trace
     using thread stack ('--itrace=g...')
   - Support call indentation ('perf script -F +callindent') to display
     call depth hierarchy on branch samples
   - Decode ETE (Embedded Trace Extension) exception packets

  Build system:

   - Add 'make install-build-deps' target to install required packages
   - Parallelize JSON and metric pre-computation in jevents.py for
     faster builds

  Vendor event/metric updates:

   - Add Intel Nova Lake events and update tables for existing models
   - Update AMD Zen 5 and Zen 6 core events
   - Update Arm64 Tegra410 metrics and PowerPC hcalls

  Internal changes and fixes:

   - Harden trace-event and synthetic event parsing against corrupted
     data
   - Fix unwinding of multi-threaded processes in libdw unwinder
   - Fix memory leaks in various commands and python bindings
   - Speed up 'perf test' shell tests"

* tag 'perf-tools-for-v7.3-2026-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (232 commits)
  perf vendor events arm64: Fix Tegra410 Olympus event 0x0197
  perf vendor events arm64: fix swapped MetricGroup for Tegra410 L1 prefetcher metrics
  perf evlist: Warn when 'sleep' workload is used without system-wide (-a) option
  perf c2c: document function view in perf-c2c man page
  perf c2c: add function view browser UI and cacheline detail
  perf c2c: build and finalize the function view hierarchy
  perf c2c: add function view hierarchy entry creation
  perf c2c: add function view stats merge and memory management
  perf c2c: add HPP list parsing for function view columns
  perf c2c: add column rendering for function view
  perf c2c: add function view model skeleton
  perf c2c: extract shared data structures into util/c2c.h
  perf test sample-parsing: Validate PERF_FORMAT_GROUP values without LOST
  perf dso: Replace assert with runtime check in dso__read_symbol()
  perf dso: Guard against cache underflow on short reads in dso_cache__memcpy()
  perf dso: Use stored fd error instead of stale errno in file_read() and file_size()
  perf dso: Guard close() against invalid fd in dso__decompress_kmodule_path()
  perf dso: Guard against errno==0 when dso__get_filename() returns NULL
  perf build: install-build-deps: add RHEL family devel package mapping
  perf build: Remove leftover feature tests for removed cxx and clang support
  ...

2 files changed, 54 insertions, 35 deletions

diff --git a/tools/scripts/Makefile.arch b/tools/scripts/Makefile.arch
index eabfe9f411d9..ed5f008d400e 100644
--- a/tools/scripts/Makefile.arch
+++ b/tools/scripts/Makefile.arch
@@ -38,7 +38,13 @@ ifeq ($(ARCH),loongarch64)
        SRCARCH := loongarch
 endif
 
-LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1)
+# Probe for __LP64__ only when the compiler is installed: this runs at
+# parse time for every target, including ones that never compile, e.g.
+# install-build-deps, and would otherwise spew "gcc: not found" when the
+# compiler is not yet installed. Only the first word of CC is consulted,
+# as CC may carry arguments, e.g. 'ccache gcc'. When the guard fails it
+# prints nothing, leaving LP64 unset, as if the probe had failed.
+LP64 := $(shell if command -v $(firstword ${CC}) >/dev/null 2>&1; then echo __LP64__ | ${CC} ${CFLAGS} -E -x c -; fi | tail -n 1)
 ifeq ($(LP64), 1)
   IS_64_BIT := 1
 else
diff --git a/tools/scripts/Makefile.include b/tools/scripts/Makefile.include
index 41971a68972d..378387f62960 100644
--- a/tools/scripts/Makefile.include
+++ b/tools/scripts/Makefile.include
@@ -52,46 +52,59 @@ define allow-override
 endef
 
 ifneq ($(LLVM),)
-ifneq ($(filter %/,$(LLVM)),)
-LLVM_PREFIX := $(LLVM)
-else ifneq ($(filter -%,$(LLVM)),)
-LLVM_SUFFIX := $(LLVM)
-else ifneq ($(LLVM),1)
-$(error Invalid value for LLVM, see Documentation/kbuild/llvm.rst)
-endif
+  ifneq ($(filter %/,$(LLVM)),)
+    LLVM_PREFIX := $(LLVM)
+  else ifneq ($(filter -%,$(LLVM)),)
+    LLVM_SUFFIX := $(LLVM)
+  else ifneq ($(LLVM),1)
+    $(error Invalid value for LLVM, see Documentation/kbuild/llvm.rst)
+  endif
 
-$(call allow-override,CC,$(LLVM_PREFIX)clang$(LLVM_SUFFIX))
-$(call allow-override,AR,$(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX))
-$(call allow-override,LD,$(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX))
-$(call allow-override,CXX,$(LLVM_PREFIX)clang++$(LLVM_SUFFIX))
-$(call allow-override,STRIP,$(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX))
+  $(call allow-override,CC,$(LLVM_PREFIX)clang$(LLVM_SUFFIX))
+  $(call allow-override,CLANG,$(LLVM_PREFIX)clang$(LLVM_SUFFIX))
+  $(call allow-override,HOSTCC,$(LLVM_PREFIX)clang$(LLVM_SUFFIX))
+  $(call allow-override,AR,$(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX))
+  $(call allow-override,HOSTAR,$(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX))
+  $(call allow-override,LD,$(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX))
+  $(call allow-override,HOSTLD,$(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX))
+  $(call allow-override,CXX,$(LLVM_PREFIX)clang++$(LLVM_SUFFIX))
+  $(call allow-override,STRIP,$(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX))
+  $(call allow-override,LLVM_STRIP,$(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX))
+  $(call allow-override,LLC,$(LLVM_PREFIX)llc$(LLVM_SUFFIX))
+  $(call allow-override,LLVM_CONFIG,$(LLVM_PREFIX)llvm-config$(LLVM_SUFFIX))
+  $(call allow-override,LLVM_OBJCOPY,$(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX))
+  $(call allow-override,READELF,$(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX))
+  $(call allow-override,HOSTREADELF,$(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX))
 else
-# Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix.
-$(call allow-override,CC,$(CROSS_COMPILE)gcc)
-$(call allow-override,AR,$(CROSS_COMPILE)ar)
-$(call allow-override,LD,$(CROSS_COMPILE)ld)
-$(call allow-override,CXX,$(CROSS_COMPILE)g++)
-$(call allow-override,STRIP,$(CROSS_COMPILE)strip)
-endif
+  # Allow setting various cross-compile vars or setting CROSS_COMPILE as a prefix.
+  $(call allow-override,CC,$(CROSS_COMPILE)gcc)
+  $(call allow-override,AR,$(CROSS_COMPILE)ar)
+  $(call allow-override,LD,$(CROSS_COMPILE)ld)
+  $(call allow-override,CXX,$(CROSS_COMPILE)g++)
+  $(call allow-override,STRIP,$(CROSS_COMPILE)strip)
+  $(call allow-override,READELF,$(CROSS_COMPILE)readelf)
 
-CC_NO_CLANG := $(shell $(CC) -dM -E -x c /dev/null | grep -Fq "__clang__"; echo $$?)
+  # Host versions aren't prefixed
+  $(call allow-override,HOSTAR,ar)
+  $(call allow-override,HOSTCC,gcc)
+  $(call allow-override,HOSTLD,ld)
+  $(call allow-override,HOSTREADELF,readelf)
 
-ifneq ($(LLVM),)
-HOSTAR  ?= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
-HOSTCC  ?= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
-HOSTLD  ?= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
-else
-HOSTAR  ?= ar
-HOSTCC  ?= gcc
-HOSTLD  ?= ld
+  # Some tools still require Clang, LLC and/or LLVM utils
+  $(call allow-override,CLANG,clang)
+  $(call allow-override,LLC,llc)
+  $(call allow-override,LLVM_CONFIG,llvm-config)
+  $(call allow-override,LLVM_OBJCOPY,llvm-objcopy)
+  $(call allow-override,LLVM_STRIP,llvm-strip)
 endif
 
-# Some tools require Clang, LLC and/or LLVM utils
-CLANG		?= clang
-LLC		?= llc
-LLVM_CONFIG	?= llvm-config
-LLVM_OBJCOPY	?= llvm-objcopy
-LLVM_STRIP	?= llvm-strip
+# The CC_NO_CLANG probe also runs at parse time for targets that never
+# compile, so guard it with 'command -v': when the compiler is not yet
+# installed, e.g. the first install-build-deps run, it would otherwise
+# spew "gcc: not found". Only the first word of CC is consulted, as CC
+# may carry arguments, e.g. 'ccache gcc'. A missing compiler leaves
+# CC_NO_CLANG at 1, as if the probe had failed.
+CC_NO_CLANG := $(shell if command -v $(firstword $(CC)) >/dev/null 2>&1; then $(CC) -dM -E -x c /dev/null; fi | grep -Fq "__clang__"; echo $$?)
 
 # Some tools require bpftool
 SYSTEM_BPFTOOL	?= bpftool