commit 9f1984c6ae30e2a379751339ce3375a21099b5d4 upstream
LLVM's integrated assembler does not accept r15 as mrc operand.
arch/arm/boot/compressed/head.S:1267:16: error: operand must be a register in range [r0, r14] or apsr_nzcv
1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate D cache
^
Use APSR_nzcv instead of r15. The GNU assembler supports this
syntax since binutils 2.21 [0].
[0] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=db472d6ff0f438a21b357249a9b48e4b74498076
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 790756c7e0229dedc83bf058ac69633045b1000e upstream It looks like a section directive was using "Solaris style" to declare the section flags. Replace this with the GNU style so that Clang's integrated assembler can assemble this directive. The modified instances were identified via: $ ag \.section | grep # Link: https://ftp.gnu.org/old-gnu/Manuals/gas-2.9.1/html_chapter/as_7.html#SEC119 Link: https://github.com/ClangBuiltLinux/linux/issues/744 Link: https://bugs.llvm.org/show_bug.cgi?id=43759 Link: https://reviews.llvm.org/D69296 Acked-by: Nicolas Pitre <nico@fluxnic.net> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Suggested-by: Fangrui Song <maskray@google.com> Suggested-by: Jian Cai <jiancai@google.com> Suggested-by: Peter Smith <peter.smith@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a92882a4d270fbcc021ee6848de5e48b7f0d27f3 ]
In the decompressor's head.S we need to start with an instruction that
is some kind of NOP, but also mimics as the PE/COFF header, when the
kernel is linked as an UEFI application. The clever solution here is
"tstne r0, #0x4d000", which in the worst case just clobbers the
condition flags, and bears the magic "MZ" signature in the lowest 16 bits.
However the encoding used (0x13105a4d) is actually not valid, since bits
[15:12] are supposed to be 0 (written as "(0)" in the ARM ARM).
Violating this is UNPREDICTABLE, and *can* trigger an UNDEFINED
exception. Common Cortex cores seem to ignore those bits, but QEMU
chooses to trap, so the code goes fishing because of a missing exception
handler at this point. We are just saved by the fact that commonly (with
-kernel or when running from U-Boot) the "Z" bit is set, so the
instruction is never executed. See [0] for more details.
To make things more robust and avoid UNPREDICTABLE behaviour in the
kernel code, lets replace this with a "two-instruction NOP":
The first instruction is an exclusive OR, the effect of which the second
instruction reverts. This does not leave any trace, neither in a
register nor in the condition flags. Also it's a perfectly valid
encoding. Kudos to Peter Maydell for coming up with this gem.
[0] https://lore.kernel.org/qemu-devel/YTPIdbUCmwagL5%2FD@os.inf.tu-dresden.de/T/
Link: https://lore.kernel.org/linux-arm-kernel/20210908162617.104962-1-andre.przywara@arm.com/T/
Fixes: 81a0bc39ea19 ("ARM: add UEFI stub support")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reported-by: Adam Lackorzynski <adam@l4re.org>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit eaf6cc7165c9c5aa3c2f9faa03a98598123d0afb upstream.
Both the decompressor code and the kasan logic try to override
the memcpy() and memmove() definitions, which leading to a clash
in a KASAN-enabled kernel with XZ decompression:
arch/arm/boot/compressed/decompress.c:50:9: error: 'memmove' macro redefined [-Werror,-Wmacro-redefined]
#define memmove memmove
^
arch/arm/include/asm/string.h:59:9: note: previous definition is here
#define memmove(dst, src, len) __memmove(dst, src, len)
^
arch/arm/boot/compressed/decompress.c:51:9: error: 'memcpy' macro redefined [-Werror,-Wmacro-redefined]
#define memcpy memcpy
^
arch/arm/include/asm/string.h:58:9: note: previous definition is here
#define memcpy(dst, src, len) __memcpy(dst, src, len)
^
Here we want the set of functions from the decompressor, so undefine
the other macros before the override.
Link: https://lore.kernel.org/linux-arm-kernel/CACRpkdZYJogU_SN3H9oeVq=zJkRgRT1gDz3xp59gdqWXxw-B=w@mail.gmail.com/
Link: https://lore.kernel.org/lkml/202105091112.F5rmd4By-lkp@intel.com/
Fixes: d6d51a96c7d6 ("ARM: 9014/2: Replace string mem* functions for KASan")
Fixes: a7f464f3db93 ("ARM: 7001/2: Wire up support for the XZ decompressor")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b30d0289de72c62516df03fdad8d53f552c69839 upstream. The merge_fdt_bootargs() function by definition consumes more than 1024 bytes of stack because it has a 1024 byte command line on the stack, meaning that we always get a warning when building this file: arch/arm/boot/compressed/atags_to_fdt.c: In function 'merge_fdt_bootargs': arch/arm/boot/compressed/atags_to_fdt.c:98:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=] However, as this is the decompressor and we know that it has a very shallow call chain, and we do not actually risk overflowing the kernel stack at runtime here. This just shuts up the warning by disabling the warning flag for this file. Tested on Nexus 7 2012 builds. Acked-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: David Heidelberg <david@ixit.cz> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: <stable@vger.kernel.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c4e792d1acce31c2eb7b9193ab06ab94de05bf42 upstream. The LLVM ld.lld linker uses a different symbol type for __bss_start, resulting in the calculation of KBSS_SZ to be thrown off. Up until now, this has gone unnoticed as it only affects the appended DTB case, but pending changes for ARM in the way the decompressed kernel is cleaned from the caches has uncovered this problem. On a ld.lld build: $ nm vmlinux |grep bss_ c1c22034 D __bss_start c1c86e98 B __bss_stop resulting in $ readelf -s arch/arm/boot/compressed/vmlinux | grep bss_size 433: c1c86e98 0 NOTYPE GLOBAL DEFAULT ABS _kernel_bss_size which is obviously incorrect, and may cause the cache clean to access unmapped memory, or cause the size calculation to wrap, resulting in no cache clean to be performed at all. Fix this by updating the sed regex to take D type symbols into account. Link: https://lore.kernel.org/linux-arm-kernel/6c65bcef-d4e7-25fa-43cf-2c435bb61bb9@collabora.com/ Link: https://lore.kernel.org/linux-arm-kernel/20210205085220.31232-1-ardb@kernel.org/ Cc: <stable@vger.kernel.org> # v4.19+ Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Reported-by: Guillaume Tucker <guillaume.tucker@collabora.com> Reported-by: "kernelci.org bot" <bot@kernelci.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2acb909750431030b65a0a2a17fd8afcbd813a84 ]
It was observed that decompressor running on hardware implementing ARM v8.2
Load/Store Multiple Atomicity and Ordering Control (LSMAOC), say, as guest,
would stuck just after:
Uncompressing Linux... done, booting the kernel.
The reason is that it clears nTLSMD bit when disabling caches:
nTLSMD, bit [3]
When ARMv8.2-LSMAOC is implemented:
No Trap Load Multiple and Store Multiple to
Device-nGRE/Device-nGnRE/Device-nGnRnE memory.
0b0 All memory accesses by A32 and T32 Load Multiple and Store
Multiple at EL1 or EL0 that are marked at stage 1 as
Device-nGRE/Device-nGnRE/Device-nGnRnE memory are trapped and
generate a stage 1 Alignment fault.
0b1 All memory accesses by A32 and T32 Load Multiple and Store
Multiple at EL1 or EL0 that are marked at stage 1 as
Device-nGRE/Device-nGnRE/Device-nGnRnE memory are not trapped.
This bit is permitted to be cached in a TLB.
This field resets to 1.
Otherwise:
Reserved, RES1
So as effect we start getting traps we are not quite ready for.
Looking into history it seems that mask used for SCTLR clear came from
the similar code for ARMv4, where bit[3] is the enable/disable bit for
the write buffer. That not applicable to ARMv7 and onwards, so retire
that bit from the masks.
Fixes: 7d09e85448dfa78e3e58186c934449aaf6d49b50 ("[ARM] 4393/2: ARMv7: Add uncompressing code for the new CPU Id format")
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 29c623d64f0dcd6aa10e0eabd16233e77114090b ] Since $(NM) variable can be easily overridden for the whole build, it's better to use it instead of $(CROSS_COMPILE)nm. The use of $(CROSS_COMPILE) prefixed variables where their calculated equivalents can be used is incorrect. This fixes issues with builds where $(NM) is set to llvm-nm. Link: https://github.com/ClangBuiltLinux/linux/issues/766 Signed-off-by: Dmitry Golovin <dima@golovin.in> Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Cc: Matthias Maennich <maennich@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c962369d72f286659e6446919f88d69b943cb4d ]
The size field of the tag header structure is supposed to be set to the
size of a tag structure including the header.
Fixes: c772568788b5f0 ("ARM: add additional table to compressed kernel")
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 89604523a76eb3e13014b2bdab7f8870becee284 upstream.
When using plugins, GCC requires that the -fplugin= options precedes
any of its plugin arguments appearing on the command line as well.
This is usually not a concern, but as it turns out, this requirement
is causing some issues with ARM's per-task stack protector plugin
and Kbuild's implementation of $(cc-option).
When the per-task stack protector plugin is enabled, and we tweak
the implementation of cc-option not to pipe the stderr output of
GCC to /dev/null, the following output is generated when GCC is
executed in the context of cc-option:
cc1: error: plugin arm_ssp_per_task_plugin should be specified before \
-fplugin-arg-arm_ssp_per_task_plugin-tso=1 in the command line
cc1: error: plugin arm_ssp_per_task_plugin should be specified before \
-fplugin-arg-arm_ssp_per_task_plugin-offset=24 in the command line
These errors will cause any option passed to cc-option to be treated
as unsupported, which is obviously incorrect.
The cause of this issue is the fact that the -fplugin= argument is
added to GCC_PLUGINS_CFLAGS, whereas the arguments above are added
to KBUILD_CFLAGS, and the contents of the former get filtered out of
the latter before being passed to the GCC running the cc-option test,
and so the -fplugin= option does not appear at all on the GCC command
line.
Adding the arguments to GCC_PLUGINS_CFLAGS instead of KBUILD_CFLAGS
would be the correct approach here, if it weren't for the fact that we
are using $(eval) to defer the moment that they are added until after
asm-offsets.h is generated, which is after the point where the contents
of GCC_PLUGINS_CFLAGS are added to KBUILD_CFLAGS. So instead, we have
to add our plugin arguments to both.
For similar reasons, we cannot append DISABLE_ARM_SSP_PER_TASK_PLUGIN
to KBUILD_CFLAGS, as it will be passed to GCC when executing in the
context of cc-option, whereas the other plugin arguments will have
been filtered out, resulting in a similar error and false negative
result as above. So add it to ccflags-y instead.
Fixes: 189af4657186da08 ("ARM: smp: add support for per-task stack canaries")
Reported-by: Merlijn Wajer <merlijn@wizzup.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>