From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- scripts/checkstack.pl | 208 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 208 insertions(+) create mode 100755 scripts/checkstack.pl (limited to 'scripts/checkstack.pl') diff --git a/scripts/checkstack.pl b/scripts/checkstack.pl new file mode 100755 index 000000000..14ce31f73 --- /dev/null +++ b/scripts/checkstack.pl @@ -0,0 +1,208 @@ +#!/usr/bin/env perl +# SPDX-License-Identifier: GPL-2.0 + +# Check the stack usage of functions +# +# Copyright Joern Engel +# Inspired by Linus Torvalds +# Original idea maybe from Keith Owens +# s390 port and big speedup by Arnd Bergmann +# Mips port by Juan Quintela +# Arm port by Holger Schurig +# Random bits by Matt Mackall +# M68k port by Geert Uytterhoeven and Andreas Schwab +# AArch64, PARISC ports by Kyle McMartin +# sparc port by Martin Habets +# ppc64le port by Breno Leitao +# riscv port by Wadim Mueller +# loongarch port by Youling Tang +# +# Usage: +# objdump -d vmlinux | scripts/checkstack.pl [arch] [min_stack] +# +# TODO : Port to all architectures (one regex per arch) + +use strict; + +# check for arch +# +# $re is used for two matches: +# $& (whole re) matches the complete objdump line with the stack growth +# $1 (first bracket) matches the size of the stack growth +# +# $dre is similar, but for dynamic stack redutions: +# $& (whole re) matches the complete objdump line with the stack growth +# $1 (first bracket) matches the dynamic amount of the stack growth +# +# $sub: subroutine for special handling to check stack usage. +# +# use anything else and feel the pain ;) +my (@stack, $re, $dre, $sub, $x, $xs, $funcre, $min_stack); +{ + my $arch = shift; + if ($arch eq "") { + $arch = `uname -m`; + chomp($arch); + } + + $min_stack = shift; + if ($min_stack eq "" || $min_stack !~ /^\d+$/) { + $min_stack = 512; + } + + $x = "[0-9a-f]"; # hex character + $xs = "[0-9a-f ]"; # hex character or space + $funcre = qr/^$x* <(.*)>:$/; + if ($arch =~ '^(aarch|arm)64$') { + #ffffffc0006325cc: a9bb7bfd stp x29, x30, [sp, #-80]! + #a110: d11643ff sub sp, sp, #0x590 + $re = qr/^.*stp.*sp, ?\#-([0-9]{1,8})\]\!/o; + $dre = qr/^.*sub.*sp, sp, #(0x$x{1,8})/o; + } elsif ($arch eq 'arm') { + #c0008ffc: e24dd064 sub sp, sp, #100 ; 0x64 + $re = qr/.*sub.*sp, sp, #([0-9]{1,4})/o; + $sub = \&arm_push_handling; + } elsif ($arch =~ /^x86(_64)?$/ || $arch =~ /^i[3456]86$/) { + #c0105234: 81 ec ac 05 00 00 sub $0x5ac,%esp + # or + # 2f60: 48 81 ec e8 05 00 00 sub $0x5e8,%rsp + $re = qr/^.*[as][du][db] \$(0x$x{1,8}),\%(e|r)sp$/o; + $dre = qr/^.*[as][du][db] (%.*),\%(e|r)sp$/o; + } elsif ($arch eq 'm68k') { + # 2b6c: 4e56 fb70 linkw %fp,#-1168 + # 1df770: defc ffe4 addaw #-28,%sp + $re = qr/.*(?:linkw %fp,|addaw )#-([0-9]{1,4})(?:,%sp)?$/o; + } elsif ($arch eq 'mips64') { + #8800402c: 67bdfff0 daddiu sp,sp,-16 + $re = qr/.*daddiu.*sp,sp,-([0-9]{1,8})/o; + } elsif ($arch eq 'mips') { + #88003254: 27bdffe0 addiu sp,sp,-32 + $re = qr/.*addiu.*sp,sp,-([0-9]{1,8})/o; + } elsif ($arch eq 'nios2') { + #25a8: defffb04 addi sp,sp,-20 + $re = qr/.*addi.*sp,sp,-([0-9]{1,8})/o; + } elsif ($arch eq 'openrisc') { + # c000043c: 9c 21 fe f0 l.addi r1,r1,-272 + $re = qr/.*l\.addi.*r1,r1,-([0-9]{1,8})/o; + } elsif ($arch eq 'parisc' || $arch eq 'parisc64') { + $re = qr/.*ldo ($x{1,8})\(sp\),sp/o; + } elsif ($arch eq 'powerpc' || $arch =~ /^ppc(64)?(le)?$/ ) { + # powerpc : 94 21 ff 30 stwu r1,-208(r1) + # ppc64(le) : 81 ff 21 f8 stdu r1,-128(r1) + $re = qr/.*st[dw]u.*r1,-($x{1,8})\(r1\)/o; + } elsif ($arch =~ /^s390x?$/) { + # 11160: a7 fb ff 60 aghi %r15,-160 + # or + # 100092: e3 f0 ff c8 ff 71 lay %r15,-56(%r15) + $re = qr/.*(?:lay|ag?hi).*\%r15,-([0-9]+)(?:\(\%r15\))?$/o; + } elsif ($arch eq 'sparc' || $arch eq 'sparc64') { + # f0019d10: 9d e3 bf 90 save %sp, -112, %sp + $re = qr/.*save.*%sp, -([0-9]{1,8}), %sp/o; + } elsif ($arch =~ /^riscv(64)?$/) { + #ffffffff8036e868: c2010113 addi sp,sp,-992 + $re = qr/.*addi.*sp,sp,-([0-9]{1,8})/o; + } elsif ($arch =~ /^loongarch(32|64)?$/) { + #9000000000224708: 02ff4063 addi.d $sp, $sp, -48(0xfd0) + $re = qr/.*addi\..*sp, .*sp, -([0-9]{1,8}).*/o; + } else { + print("wrong or unknown architecture \"$arch\"\n"); + exit + } +} + +# +# To count stack usage of push {*, fp, ip, lr, pc} instruction in ARM, +# if FRAME POINTER is enabled. +# e.g. c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc} +# +sub arm_push_handling { + my $regex = qr/.*push.*fp, ip, lr, pc}/o; + my $size = 0; + my $line_arg = shift; + + if ($line_arg =~ m/$regex/) { + $size = $line_arg =~ tr/,//; + $size = ($size + 1) * 4; + } + + return $size; +} + +# +# main() +# +my ($func, $file, $lastslash, $total_size, $addr, $intro); + +$total_size = 0; + +while (my $line = ) { + if ($line =~ m/$funcre/) { + $func = $1; + next if $line !~ m/^($x*)/; + if ($total_size > $min_stack) { + push @stack, "$intro$total_size\n"; + } + $addr = "0x$1"; + $intro = "$addr $func [$file]:"; + my $padlen = 56 - length($intro); + while ($padlen > 0) { + $intro .= ' '; + $padlen -= 8; + } + + $total_size = 0; + } + elsif ($line =~ m/(.*):\s*file format/) { + $file = $1; + $file =~ s/\.ko//; + $lastslash = rindex($file, "/"); + if ($lastslash != -1) { + $file = substr($file, $lastslash + 1); + } + } + elsif ($line =~ m/$re/) { + my $size = $1; + $size = hex($size) if ($size =~ /^0x/); + + if ($size > 0xf0000000) { + $size = - $size; + $size += 0x80000000; + $size += 0x80000000; + } + next if ($size > 0x10000000); + + $total_size += $size; + } + elsif (defined $dre && $line =~ m/$dre/) { + my $size = $1; + + $size = hex($size) if ($size =~ /^0x/); + $total_size += $size; + } + elsif (defined $sub) { + my $size = &$sub($line); + + $total_size += $size; + } +} +if ($total_size > $min_stack) { + push @stack, "$intro$total_size\n"; +} + +# Sort output by size (last field) and function name if size is the same +sub sort_lines { + my ($a, $b) = @_; + + my $num_a = $1 if $a =~ /:\t*(\d+)$/; + my $num_b = $1 if $b =~ /:\t*(\d+)$/; + my $func_a = $1 if $a =~ / (.*):/; + my $func_b = $1 if $b =~ / (.*):/; + + if ($num_a != $num_b) { + return $num_b <=> $num_a; + } else { + return $func_a cmp $func_b; + } +} + +print sort { sort_lines($a, $b) } @stack; -- cgit v1.3.1