commit f43b9876e8 upstream.
Do fine-grained Kconfig for all the various retbleed parts.
NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitigation to IBPB, you might not like this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: there is no CONFIG_OBJTOOL]
[cascardo: objtool calling and option parsing has changed]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[bwh: Backported to 5.10:
- In scripts/Makefile.build, add the objtool option with an ifdef
block, same as for other options
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a09a6e2399 upstream.
Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done before the first actual RET
instruction.
Entry points are those that either have UNWIND_HINT_ENTRY, which acts
as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or
those that have UWIND_HINT_IRET_REGS at +0.
This is basically a variant of validate_branch() that is
intra-function and it will simply follow all branches from marked
entry points and ensures that all paths lead to ANNOTATE_UNRET_END.
If a path hits RET or an indirection the path is a fail and will be
reported.
There are 3 ANNOTATE_UNRET_END instances:
- UNTRAIN_RET itself
- exception from-kernel; this path doesn't need UNTRAIN_RET
- all early exceptions; these also don't need UNTRAIN_RET
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
[cascardo: arch/x86/entry/entry_64.S no pt_regs return at .Lerror_entry_done_lfence]
[cascardo: tools/objtool/builtin-check.c no link option validation]
[cascardo: tools/objtool/check.c opts.ibt is ibt]
[cascardo: tools/objtool/include/objtool/builtin.h leave unret option as bool, no struct opts]
[cascardo: objtool is still called from scripts/link-vmlinux.sh]
[cascardo: no IBT support]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
[bwh: Backported to 5.10:
- In scripts/link-vmlinux.sh, use "test -n" instead of is_enabled
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 28438794ab upstream.
Since commit f02e8a6596 ("module: Sort exported symbols"),
EXPORT_SYMBOL* is placed in the individual section ___ksymtab(_gpl)+<sym>
(3 leading underscores instead of 2).
Since then, modpost cannot detect the bad combination of EXPORT_SYMBOL
and __init/__exit.
Fix the .fromsec field.
Fixes: f02e8a6596 ("module: Sort exported symbols")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit dcea997bee ]
If a function lives in a section other than .text, but .text also exists
in the object, faddr2line may wrongly assume .text. This can result in
comically wrong output. For example:
$ scripts/faddr2line vmlinux.o enter_from_user_mode+0x1c
enter_from_user_mode+0x1c/0x30:
find_next_bit at /home/jpoimboe/git/linux/./include/linux/find.h:40
(inlined by) perf_clear_dirty_counters at /home/jpoimboe/git/linux/arch/x86/events/core.c:2504
Fix it by passing the section name to addr2line, unless the object file
is vmlinux, in which case the symbol table uses absolute addresses.
Fixes: 1d1a0e7c51 ("scripts/faddr2line: Fix overlapping text section failures")
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/7d25bc1408bd3a750ac26e60d2f2815a5f4a8363.1654130536.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1f7a6cf6b0 ]
MAGIC_START("IKCFG_ST") and MAGIC_END("IKCFG_ED") are moved out
from the kernel_config_data variable.
Thus, we parse kernel_config_data directly instead of considering
offset of MAGIC_START and MAGIC_END.
Fixes: 13610aa908 ("kernel/configs: use .incbin directive to embed config_data.gz")
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d6b732666a ]
The return value of is_arm_mapping_symbol() is unpredictable when "$"
is passed in.
strchr(3) says:
The strchr() and strrchr() functions return a pointer to the matched
character or NULL if the character is not found. The terminating null
byte is considered part of the string, so that if c is specified as
'\0', these functions return a pointer to the terminator.
When str[1] is '\0', strchr("axtd", str[1]) is not NULL, and str[2] is
referenced (i.e. buffer overrun).
Test code
---------
char str1[] = "abc";
char str2[] = "ab";
strcpy(str1, "$");
strcpy(str2, "$");
printf("test1: %d\n", is_arm_mapping_symbol(str1));
printf("test2: %d\n", is_arm_mapping_symbol(str2));
Result
------
test1: 0
test2: 1
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b5beffa20d ]
With the `-z unique-symbol` linker flag or any similar mechanism,
it is possible to trigger the following:
ERROR: modpost: "param_set_uint.0" [vmlinux] is a static EXPORT_SYMBOL
The reason is that for now the condition from remove_dot():
if (m && (s[n + m] == '.' || s[n + m] == 0))
which was designed to test if it's a dot or a '\0' after the suffix
is never satisfied.
This is due to that `s[n + m]` always points to the last digit of a
numeric suffix, not on the symbol next to it (from a custom debug
print added to modpost):
param_set_uint.0, s[n + m] is '0', s[n + m + 1] is '\0'
So it's off-by-one and was like that since 2014.
Fix this for the sake of any potential upcoming features, but don't
bother stable-backporting, as it's well hidden -- apart from that
LD flag, it can be triggered only with GCC LTO which never landed
upstream.
Fixes: fcd38ed0ff ("scripts: modpost: fix compilation warning")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1d1a0e7c51 ]
There have been some recent reports of faddr2line failures:
$ scripts/faddr2line sound/soundcore.ko sound_devnode+0x5/0x35
bad symbol size: base: 0x0000000000000000 end: 0x0000000000000000
$ ./scripts/faddr2line vmlinux.o enter_from_user_mode+0x24
bad symbol size: base: 0x0000000000005fe0 end: 0x0000000000005fe0
The problem is that faddr2line is based on 'nm', which has a major
limitation: it doesn't know how to distinguish between different text
sections. So if an offset exists in multiple text sections in the
object, it may fail.
Rewrite faddr2line to be section-aware, by basing it on readelf.
Fixes: 67326666e2 ("scripts: add script for translating stack dump function offsets")
Reported-by: Kaiwan N Billimoria <kaiwan.billimoria@gmail.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lore.kernel.org/r/29ff99f86e3da965b6e46c1cc2d72ce6528c17c3.1652382321.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c40160f299 upstream.
While the latent entropy plugin mostly doesn't derive entropy from
get_random_const() for measuring the call graph, when __latent_entropy is
applied to a constant, then it's initialized statically to output from
get_random_const(). In that case, this data is derived from a 64-bit
seed, which means a buffer of 512 bits doesn't really have that amount
of compile-time entropy.
This patch fixes that shortcoming by just buffering chunks of
/dev/urandom output and doling it out as requested.
At the same time, it's important that we don't break the use of
-frandom-seed, for people who want the runtime benefits of the latent
entropy plugin, while still having compile-time determinism. In that
case, we detect whether gcc's set_random_seed() has been called by
making a call to get_random_seed(noinit=true) in the plugin init
function, which is called after set_random_seed() is called but before
anything that calls get_random_seed(noinit=false), and seeing if it's
zero or not. If it's not zero, we're in deterministic mode, and so we
just generate numbers with a basic xorshift prng.
Note that we don't detect if -frandom-seed is being used using the
documented local_tick variable, because it's assigned via:
local_tick = (unsigned) tv.tv_sec * 1000 + tv.tv_usec / 1000;
which may well overflow and become -1 on its own, and so isn't
reliable: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105171
[kees: The 256 byte rnd_buf size was chosen based on average (250),
median (64), and std deviation (575) bytes of used entropy for a
defconfig x86_64 build]
Fixes: 38addce8b6 ("gcc-plugins: Add latent_entropy plugin")
Cc: stable@vger.kernel.org
Cc: PaX Team <pageexec@freemail.hu>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220405222815.21155-1-Jason@zx2c4.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 27e9faf415 ]
Since STRING_CST may not be NUL terminated, strncmp() was used for check
for equality. However, this may lead to mismatches for longer section
names where the start matches the tested-for string. Test for exact
equality by checking for the presences of NUL termination.
Cc: Alexander Popov <alex.popov@linux.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1b9e740a81 ]
When the KCONFIG_AUTOCONFIG is specified (e.g. export \
KCONFIG_AUTOCONFIG=output/config/auto.conf), the directory of
include/config/ will not be created, so kconfig can't create deps
files in it and auto.conf can't be generated.
Signed-off-by: Jing Leng <jleng@ambarella.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8a4c5b2a6d ]
The 'shell' built-in only returns the first 256 bytes of the command's
output. In some cases, 'shell' is used to return a path; by bumping up
the buffer size to 4096 this lets us capture up to PATH_MAX.
The specific case where I ran into this was due to commit 1e860048c5
("gcc-plugins: simplify GCC plugin-dev capability test"). After this
change, we now use `$(shell,$(CC) -print-file-name=plugin)` to return
a path; if the gcc path is particularly long, then the path ends up
truncated at the 256 byte mark, which makes the HAVE_GCC_PLUGINS
depends test always fail.
Signed-off-by: Brenda Streiff <brenda.streiff@ni.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6a3193cdd5 upstream.
Merge module sections only when using Clang LTO. With ld.bfd, merging
sections does not appear to update the symbol tables for the module,
e.g. 'readelf -s' shows the value that a symbol would have had, if
sections were not merged. ld.lld does not show this problem.
The stale symbol table breaks gdb's function disassembler, and presumably
other things, e.g.
gdb -batch -ex "file arch/x86/kvm/kvm.ko" -ex "disassemble kvm_init"
reads the wrong bytes and dumps garbage.
Fixes: dd2776222a ("kbuild: lto: merge module sections")
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210322234438.502582-1-seanjc@google.com
Cc: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1cf5f151d2 upstream.
-Wunaligned-access is a new warning in clang that is default enabled for
arm and arm64 under certain circumstances within the clang frontend (see
LLVM commit below). On v5.17-rc2, an ARCH=arm allmodconfig build shows
1284 total/70 unique instances of this warning (most of the instances
are in header files), which is quite noisy.
To keep a normal build green through CONFIG_WERROR, only show this
warning with W=1, which will allow automated build systems to catch new
instances of the warning so that the total number can be driven down to
zero eventually since catching unaligned accesses at compile time would
be generally useful.
Cc: stable@vger.kernel.org
Link: 35737df4dc
Link: https://github.com/ClangBuiltLinux/linux/issues/1569
Link: https://github.com/ClangBuiltLinux/linux/issues/1576
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d8adf5b92a upstream.
dtx_diff suggests to use <(...) syntax to pipe two inputs into it, but
this has never worked: The /proc/self/fds/... paths passed by the shell
will fail the `[ -f "${dtx}" ] && [ -r "${dtx}" ]` check in compile_to_dts,
but even with this check removed, the function cannot work: hexdump will
eat up the DTB magic, making the subsequent dtc call fail, as a pipe
cannot be rewound.
Simply remove this broken example, as there is already an alternative one
that works fine.
Fixes: 10eadc253d ("dtc: create tool to diff device trees")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220113081918.10387-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4eb1782eaa upstream.
Commit 85bf17b28f ("recordmcount.pl: look for jgnop instruction as well
as bcrl on s390") added a new alternative mnemonic for the existing brcl
instruction. This is required for the combination old gcc version (pre 9.0)
and binutils since version 2.37.
However at the same time this commit introduced a typo, replacing brcl with
bcrl. As a result no mcount locations are detected anymore with old gcc
versions (pre 9.0) and binutils before version 2.37.
Fix this by using the correct mnemonic again.
Reported-by: Miroslav Benes <mbenes@suse.cz>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: 85bf17b28f ("recordmcount.pl: look for jgnop instruction as well as bcrl on s390")
Link: https://lore.kernel.org/r/alpine.LSU.2.21.2112230949520.19849@pobox.suse.cz
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f4c3b83b75 upstream.
With commit 1e860048c5 ("gcc-plugins: simplify GCC plugin-dev
capability test") applied, this hunk can be way simplified because
now scripts/gcc-plugins/Kconfig only checks plugin-version.h
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67a5a68013 upstream.
Fedora Rawhide has started including gcc 11,and the g++ compiler
throws a wobbly when it hits scripts/gcc-plugins:
HOSTCXX scripts/gcc-plugins/latent_entropy_plugin.so
In file included from /usr/include/c++/11/type_traits:35,
from /usr/lib/gcc/x86_64-redhat-linux/11/plugin/include/system.h:244,
from /usr/lib/gcc/x86_64-redhat-linux/11/plugin/include/gcc-plugin.h:28,
from scripts/gcc-plugins/gcc-common.h:7,
from scripts/gcc-plugins/latent_entropy_plugin.c:78:
/usr/include/c++/11/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO
C++ 2011 standard. This support must be enabled with the -std=c++11 or -std=gnu++11 compiler options.
32 | #error This file requires compiler and library support \
In fact, it works just fine with c++11, which has been in gcc since 4.8,
and we now require 4.9 as a minimum.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/82487.1609006918@turing-police
Cc: Thomas Lindroth <thomas.lindroth@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
