#!/usr/bin/perl # 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 # IA64 port via Andreas Dilger # Arm port by Holger Schurig # sh64 port by Paul Mundt # Random bits by Matt Mackall # M68k port by Geert Uytterhoeven and Andreas Schwab # AVR32 port by Haavard Skinnemoen (Atmel) # AArch64, PARISC ports by Kyle McMartin # sparc port by Martin Habets # # Usage: # objdump -d vmlinux | scripts/checkstack.pl [arch] # # 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 # # use anything else and feel the pain ;) my (@stack, $re, $dre, $x, $xs, $funcre); { my $arch = shift; if ($arch eq "") { $arch = `uname -m`; chomp($arch); } $x = "[0-9a-f]"; # hex character $xs = "[0-9a-f ]"; # hex character or space $funcre = qr/^$x* <(.*)>:$/; if ($arch eq 'aarch64') { #ffffffc0006325cc: a9bb7bfd stp x29, x30, [sp,#-80]! $re = qr/^.*stp.*sp,\#-([0-9]{1,8})\]\!/o; } elsif ($arch eq 'arm') { #c0008ffc: e24dd064 sub sp, sp, #100 ; 0x64 $re = qr/.*sub.*sp, sp, #(([0-9]{2}|[3-9])[0-9]{2})/o; } elsif ($arch eq 'avr32') { #8000008a: 20 1d sub sp,4 #80000ca8: fa cd 05 b0 sub sp,sp,1456 $re = qr/^.*sub.*sp.*,([0-9]{1,8})/o; } elsif ($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 'ia64') { #e0000000044011fc: 01 0f fc 8c adds r12=-384,r12 $re = qr/.*adds.*r12=-(([0-9]{2}|[3-9])[0-9]{2}),r12/o; } elsif ($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 'metag') { #400026fc: 40 00 00 82 ADD A0StP,A0StP,#0x8 $re = qr/.*ADD.*A0StP,A0StP,\#(0x$x{1,8})/o; $funcre = qr/^$x* <[^\$](.*)>:$/; } elsif ($arch eq 'mips64') { #8800402c: 67bdfff0 daddiu sp,sp,-16 $re = qr/.*daddiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o; } elsif ($arch eq 'mips') { #88003254: 27bdffe0 addiu sp,sp,-32 $re = qr/.*addiu.*sp,sp,-(([0-9]{2}|[3-9])[0-9]{2})/o; } elsif ($arch eq 'parisc' || $arch eq 'parisc64') { $re = qr/.*ldo ($x{1,8})\(sp\),sp/o; } elsif ($arch eq 'ppc') { #c00029f4: 94 21 ff 30 stwu r1,-208(r1) $re = qr/.*stwu.*r1,-($x{1,8})\(r1\)/o; } elsif ($arch eq 'ppc64') { #XXX $re = qr/.*stdu.*r1,-($x{1,8})\(r1\)/o; } elsif ($arch eq 'powerpc') { $re = qr/.*st[dw]u.*r1,-($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]{2}|[3-9])[0-9]{2}) (?:\(\%r15\))?$/ox; } elsif ($arch =~ /^sh64$/) { #XXX: we only check for the immediate case presently, # though we will want to check for the movi/sub # pair for larger users. -- PFM. #a00048e0: d4fc40f0 addi.l r15,-240,r15 $re = qr/.*addi\.l.*r15,-(([0-9]{2}|[3-9])[0-9]{2}),r15/o; } elsif ($arch =~ /^blackfin$/) { # 0: 00 e8 38 01 LINK 0x4e0; $re = qr/.*[[:space:]]LINK[[:space:]]*(0x$x{1,8})/o; } elsif ($arch eq 'sparc' || $arch eq 'sparc64') { # f0019d10: 9d e3 bf 90 save %sp, -112, %sp $re = qr/.*save.*%sp, -(([0-9]{2}|[3-9])[0-9]{2}), %sp/o; } else { print("wrong or unknown architecture \"$arch\"\n"); exit } } # # main() # my ($func, $file, $lastslash); while (my $line = ) { if ($line =~ m/$funcre/) { $func = $1; } elsif ($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); next if $line !~ m/^($xs*)/; my $addr = $1; $addr =~ s/ /0/g; $addr = "0x$addr"; my $intro = "$addr $func [$file]:"; my $padlen = 56 - length($intro); while ($padlen > 0) { $intro .= ' '; $padlen -= 8; } next if ($size < 100); push @stack, "$intro$size\n"; } elsif (defined $dre && $line =~ m/$dre/) { my $size = "Dynamic ($1)"; next if $line !~ m/^($xs*)/; my $addr = $1; $addr =~ s/ /0/g; $addr = "0x$addr"; my $intro = "$addr $func [$file]:"; my $padlen = 56 - length($intro); while ($padlen > 0) { $intro .= ' '; $padlen -= 8; } push @stack, "$intro$size\n"; } } # Sort output by size (last field) print sort { ($b =~ /:\t*(\d+)$/)[0] <=> ($a =~ /:\t*(\d+)$/)[0] } @stack; m.c?id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/core/stream.c')