Revision eb35bdd7bca29a13c8ecd44e6fd747a84ce675db authored by Will Deacon on 11 September 2014, 13:38:16 UTC, committed by Will Deacon on 11 September 2014, 17:34:58 UTC
Nathan reports that we leak TLS information from the parent context
during an exec, as we don't clear the TLS registers when flushing the
thread state.
This patch updates the flushing code so that we:
(1) Unconditionally zero the tpidr_el0 register (since this is fully
context switched for native tasks and zeroed for compat tasks)
(2) Zero the tp_value state in thread_info before clearing the
tpidrr0_el0 register for compat tasks (since this is only writable
by the set_tls compat syscall and therefore not fully switched).
A missing compiler barrier is also added to the compat set_tls syscall.
Cc: <stable@vger.kernel.org>
Acked-by: Nathan Lynch <Nathan_Lynch@mentor.com>
Reported-by: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 3d8afe3
checkstack.pl
#!/usr/bin/perl
# Check the stack usage of functions
#
# Copyright Joern Engel <joern@lazybastard.org>
# Inspired by Linus Torvalds
# Original idea maybe from Keith Owens
# s390 port and big speedup by Arnd Bergmann <arnd@bergmann-dalldorf.de>
# Mips port by Juan Quintela <quintela@mandrakesoft.com>
# IA64 port via Andreas Dilger
# Arm port by Holger Schurig
# sh64 port by Paul Mundt
# Random bits by Matt Mackall <mpm@selenic.com>
# M68k port by Geert Uytterhoeven and Andreas Schwab
# AVR32 port by Haavard Skinnemoen (Atmel)
# PARISC port by Kyle McMartin <kyle@parisc-linux.org>
# sparc port by Martin Habets <errandir_news@mph.eclipse.co.uk>
#
# 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 '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 $line = <STDIN>) {
if ($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;
Computing file changes ...
