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Remove the #if statement which caused trouble for kernels that support
both ARMv6 and ARMv7. Older architectures do not implement these bits,
so it should be safe to always clear them.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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When a kernel is built covering ARMv6 to ARMv7, we omit to clear the
IT state when entering a signal handler. This can cause the first
few instructions to be conditionally executed depending on the parent
context.
In any case, the original test for >= ARMv7 is broken - ARMv6 can have
Thumb-2 support as well, and an ARMv6T2 specific build would omit this
code too.
Relax the test back to ARMv6 or greater. This results in us always
clearing the IT state bits in the PSR, even on CPUs where these bits
are reserved. However, they're reserved for the IT state, so this
should cause no harm.
Cc: <stable@vger.kernel.org>
Fixes: d71e1352e240 ("Clear the IT state when invoking a Thumb-2 signal handler")
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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On old ARM chips, unaligned accesses to memory are not trapped and
fixed. On module load, symbols are relocated, and the relocation of
__bug_table symbols is done on a u32 basis. Yet the section is not
aligned to a multiple of 4 address, but to a multiple of 2.
This triggers an Oops on pxa architecture, where address 0xbf0021ea
is the first relocation in the __bug_table section :
apply_relocate(): pxa3xx_nand: section 13 reloc 0 sym ''
Unable to handle kernel paging request at virtual address bf0021ea
pgd = e1cd0000
[bf0021ea] *pgd=c1cce851, *pte=c1cde04f, *ppte=c1cde01f
Internal error: Oops: 23 [#1] ARM
Modules linked in:
CPU: 0 PID: 606 Comm: insmod Not tainted 4.2.0-rc8-next-20150828-cm-x300+ #887
Hardware name: CM-X300 module
task: e1c68700 ti: e1c3e000 task.ti: e1c3e000
PC is at apply_relocate+0x2f4/0x3d4
LR is at 0xbf0021ea
pc : [<c000e7c8>] lr : [<bf0021ea>] psr: 80000013
sp : e1c3fe30 ip : 60000013 fp : e49e8c60
r10: e49e8fa8 r9 : 00000000 r8 : e49e7c58
r7 : e49e8c38 r6 : e49e8a58 r5 : e49e8920 r4 : e49e8918
r3 : bf0021ea r2 : bf007034 r1 : 00000000 r0 : bf000000
Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 0000397f Table: c1cd0018 DAC: 00000051
Process insmod (pid: 606, stack limit = 0xe1c3e198)
[<c000e7c8>] (apply_relocate) from [<c005ce5c>] (load_module+0x1248/0x1f5c)
[<c005ce5c>] (load_module) from [<c005dc54>] (SyS_init_module+0xe4/0x170)
[<c005dc54>] (SyS_init_module) from [<c000a420>] (ret_fast_syscall+0x0/0x38)
Fix this by ensuring entries in __bug_table are all aligned to at least
of multiple of 4. This transforms a module section __bug_table as :
- [12] __bug_table PROGBITS 00000000 002232 000018 00 A 0 0 1
+ [12] __bug_table PROGBITS 00000000 002232 000018 00 A 0 0 4
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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When Xen is copying data to/from the guest it will check if the kernel
has the right to do the access. If not, the hypercall will return an
error.
After the commit a5e090acbf545c0a3b04080f8a488b17ec41fe02 "ARM:
software-based privileged-no-access support", the kernel can't access
any longer the user space by default. This will result to fail on every
hypercall made by the userspace (i.e via privcmd).
We have to enable the userspace access and then restore the correct
permission every time the privcmd is used to made an hypercall.
I didn't find generic helpers to do a these operations, so the change
is only arm32 specific.
Reported-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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We need to have memory dependencies on get_domain/set_domain to avoid
the compiler over-optimising these inline assembly instructions.
Loads/stores must not be reordered across a set_domain(), so introduce
a compiler barrier for that assembly.
The value of get_domain() must not be cached across a set_domain(), but
we still want to allow the compiler to optimise it away. Introduce a
dependency on current_thread_info()->cpu_domain to avoid this; the new
memory clobber in set_domain() should therefore cause the compiler to
re-load this. The other advantage of using this is we should have its
address in the register set already, or very soon after at most call
sites.
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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As of 1eef5d2f1b46 ("ARM: domains: switch to keeping domain value in
register") we no longer need to include asm/domains.h into
asm/thread_info.h. Remove it.
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The use of get_domain() in copy_thread() results in an oops on
ARMv7M/noMMU systems. The thread cpu_domain value is only used when
CONFIG_CPU_USE_DOMAINS is enabled, so there's no need to save the
value in copy_thread() except when this is enabled, and this option
will never be enabled on these platforms.
Unhandled exception: IPSR = 00000006 LR = fffffff1
CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-next-20150909-00001-gb8ec5ad #41
Hardware name: NXP LPC18xx/43xx (Device Tree)
task: 2823fbe0 ti: 2823c000 task.ti: 2823c000
PC is at copy_thread+0x18/0x92
LR is at copy_thread+0x19/0x92
pc : [<2800a46e>] lr : [<2800a46f>] psr: 4100000b
sp : 2823df00 ip : 00000000 fp : 287c81c0
r10: 00000000 r9 : 00800300 r8 : 287c8000
r7 : 287c8000 r6 : 2818908d r5 : 00000000 r4 : 287ca000
r3 : 00000000 r2 : 00000000 r1 : fffffff0 r0 : 287ca048
xPSR: 4100000b
Reported-by: Ariel D'Alessandro <ariel@vanguardiasur.com.ar>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This macro is never referenced, remove it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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NWFPE needs to access userspace to check whether the next instruction
is another FP instruction. Allow userspace access for this read.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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While working on the 32-bit ARM port of UEFI, I noticed a strange
corruption in the kernel log. The following snprintf() statement
(in drivers/firmware/efi/efi.c:efi_md_typeattr_format())
snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
was producing the following output in the log:
| | | | | |WB|WT|WC|UC]
| | | | | |WB|WT|WC|UC]
| | | | | |WB|WT|WC|UC]
|RUN| | | | |WB|WT|WC|UC]*
|RUN| | | | |WB|WT|WC|UC]*
| | | | | |WB|WT|WC|UC]
|RUN| | | | |WB|WT|WC|UC]*
| | | | | |WB|WT|WC|UC]
|RUN| | | | | | | |UC]
|RUN| | | | | | | |UC]
As it turns out, this is caused by incorrect code being emitted for
the string() function in lib/vsprintf.c. The following code
if (!(spec.flags & LEFT)) {
while (len < spec.field_width--) {
if (buf < end)
*buf = ' ';
++buf;
}
}
for (i = 0; i < len; ++i) {
if (buf < end)
*buf = *s;
++buf; ++s;
}
while (len < spec.field_width--) {
if (buf < end)
*buf = ' ';
++buf;
}
when called with len == 0, triggers an issue in the GCC SRA optimization
pass (Scalar Replacement of Aggregates), which handles promotion of signed
struct members incorrectly. This is a known but as yet unresolved issue.
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932). In this particular
case, it is causing the second while loop to be executed erroneously a
single time, causing the additional space characters to be printed.
So disable the optimization by passing -fno-ipa-sra.
Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Provide a software-based implementation of the priviledged no access
support found in ARMv8.1.
Userspace pages are mapped using a different domain number from the
kernel and IO mappings. If we switch the user domain to "no access"
when we enter the kernel, we can prevent the kernel from touching
userspace.
However, the kernel needs to be able to access userspace via the
various user accessor functions. With the wrapping in the previous
patch, we can temporarily enable access when the kernel needs user
access, and re-disable it afterwards.
This allows us to trap non-intended accesses to userspace, eg, caused
by an inadvertent dereference of the LIST_POISON* values, which, with
appropriate user mappings setup, can be made to succeed. This in turn
can allow use-after-free bugs to be further exploited than would
otherwise be possible.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Provide hooks into the kernel entry and exit paths to permit control
of userspace visibility to the kernel. The intended use is:
- on entry to kernel from user, uaccess_disable will be called to
disable userspace visibility
- on exit from kernel to user, uaccess_enable will be called to
enable userspace visibility
- on entry from a kernel exception, uaccess_save_and_disable will be
called to save the current userspace visibility setting, and disable
access
- on exit from a kernel exception, uaccess_restore will be called to
restore the userspace visibility as it was before the exception
occurred.
These hooks allows us to keep userspace visibility disabled for the
vast majority of the kernel, except for localised regions where we
want to explicitly access userspace.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The following structure is just asking for trouble:
#ifdef CONFIG_symbol
.macro foo
...
.endm
.macro bar
...
.endm
.macro baz
...
.endm
#else
.macro foo
...
.endm
.macro bar
...
.endm
#ifdef CONFIG_symbol2
.macro baz
...
.endm
#else
.macro baz
...
.endm
#endif
#endif
such as one defintion being updated, but the other definitions miss out.
Where the contents of a macro needs to be conditional, the hint is in
the first clause of this very sentence. "contents" "conditional". Not
multiple separate definitions, especially not when much of the macro
is the same between different configs.
This patch fixes this bad style, which had caused the Thumb2 code to
miss-out on the uaccess updates.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Provide uaccess_save_and_enable() and uaccess_restore() to permit
control of userspace visibility to the kernel, and hook these into
the appropriate places in the kernel where we need to access
userspace.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Improve the do_ldrd_abort macro code - firstly, it inefficiently checks
for the LDRD encoding by doing a multi-stage test of various bits. This
can be simplified by generating a mask, bitmasking the instruction and
then comparing the result.
Secondly, we want to be able to test the result rather than branching
to do_DataAbort, so remove the branch at the end and rename the macro
to 'teq_ldrd' to reflect it's new usage. teq_ldrd macro returns 'eq'
if the instruction was a LDRD.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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DOMAIN_TABLE is not used; in any case, it aliases to the kernel domain.
Remove this definition.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Keep the machine vectors in its own domain to avoid software based
user access control from making the vector code inaccessible, and
thereby deadlocking the machine.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Since we switched to early trap initialisation in 94e5a85b3be0
("ARM: earlier initialization of vectors page") we haven't been writing
directly to the vectors page, and so there's no need for this domain
to be in manager mode. Switch it to client mode.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Provide a macro to generate the mask for a domain, rather than using
domain_val(, DOMAIN_MANAGER) which won't work when CPU_USE_DOMAINS
is turned off.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Rather than modifying both the domain access control register and our
per-thread copy, modify only the domain access control register, and
use the per-thread copy to save and restore the register over context
switches. We can also avoid the explicit initialisation of the
init thread_info structure.
This allows us to avoid needing to gain access to the thread information
at the uaccess control sites.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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U-Boot is often used to boot the kernel on ARM boards, but uImage
is not built by "make all", so we are often inclined to do
"make all uImage" to generate DTBs, modules and uImage in a single
command, but we should notice a pitfall behind it. In fact,
"make all uImage" could generate an invalid uImage if it is run with
the parallel option (-j).
You can reproduce this problem with the following procedure:
[1] First, build "all" and "uImage" separately.
You will get a valid uImage
$ git clean -f -x -d
$ export CROSS_COMPILE=<your-tools-prefix>
$ make -s -j8 ARCH=arm multi_v7_defconfig
$ make -s -j8 ARCH=arm all
$ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 uImage
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
CHK include/generated/compile.h
Kernel: arch/arm/boot/Image is ready
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-4.2.0-rc5-00156-gdd2384a-d
Created: Sat Aug 8 23:21:35 2015
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 6138648 Bytes = 5994.77 kB = 5.85 MB
Load Address: 80208000
Entry Point: 80208000
Image arch/arm/boot/uImage is ready
$ ls -l arch/arm/boot/*Image
-rwxrwxr-x 1 masahiro masahiro 13766656 Aug 8 23:20 arch/arm/boot/Image
-rw-rw-r-- 1 masahiro masahiro 6138712 Aug 8 23:21 arch/arm/boot/uImage
-rwxrwxr-x 1 masahiro masahiro 6138648 Aug 8 23:20 arch/arm/boot/zImage
[2] Update some source file(s)
$ touch init/main.c
[3] Then, re-build "all" and "uImage" simultaneously.
You will get an invalid uImage at random.
$ make -j8 ARCH=arm UIMAGE_LOADADDR=0x80208000 all uImage
CHK include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
CHK include/generated/timeconst.h
CHK include/generated/bounds.h
CHK include/generated/asm-offsets.h
CALL scripts/checksyscalls.sh
CC init/main.o
CHK include/generated/compile.h
LD init/built-in.o
LINK vmlinux
LD vmlinux.o
MODPOST vmlinux.o
GEN .version
CHK include/generated/compile.h
UPD include/generated/compile.h
CC init/version.o
LD init/built-in.o
KSYM .tmp_kallsyms1.o
KSYM .tmp_kallsyms2.o
LD vmlinux
SORTEX vmlinux
SYSMAP System.map
OBJCOPY arch/arm/boot/Image
Building modules, stage 2.
Kernel: arch/arm/boot/Image is ready
GZIP arch/arm/boot/compressed/piggy.gzip
AS arch/arm/boot/compressed/piggy.gzip.o
Kernel: arch/arm/boot/Image is ready
LD arch/arm/boot/compressed/vmlinux
GZIP arch/arm/boot/compressed/piggy.gzip
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
UIMAGE arch/arm/boot/uImage
Image Name: Linux-4.2.0-rc5-00156-gdd2384a-d
Created: Sat Aug 8 23:23:14 2015
Image Type: ARM Linux Kernel Image (uncompressed)
Data Size: 26472 Bytes = 25.85 kB = 0.03 MB
Load Address: 80208000
Entry Point: 80208000
Image arch/arm/boot/uImage is ready
MODPOST 192 modules
AS arch/arm/boot/compressed/piggy.gzip.o
LD arch/arm/boot/compressed/vmlinux
OBJCOPY arch/arm/boot/zImage
Kernel: arch/arm/boot/zImage is ready
$ ls -l arch/arm/boot/*Image
-rwxrwxr-x 1 masahiro masahiro 13766656 Aug 8 23:23 arch/arm/boot/Image
-rw-rw-r-- 1 masahiro masahiro 26536 Aug 8 23:23 arch/arm/boot/uImage
-rwxrwxr-x 1 masahiro masahiro 6138648 Aug 8 23:23 arch/arm/boot/zImage
Please notice the uImage is extremely small when this issue is
encountered. Besides, "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, before and after the uImage log.
The root cause of this is the race condition between zImage and
uImage. Actually, uImage depends on zImage, but the dependency
between the two is only described in arch/arm/boot/Makefile.
Because arch/arm/boot/Makefile is not included from the top-level
Makefile, it cannot know the dependency between zImage and uImage.
Consequently, when we run make with the parallel option, Kbuild
updates vmlinux first, and then two different threads descends into
the arch/arm/boot/Makefile almost at the same time, one for updating
zImage and the other for uImage. While one thread is re-generating
zImage, the other also tries to update zImage before creating uImage
on top of that. zImage is overwritten by the slower thread and then
uImage is created based on the half-written zImage.
This is the reason why "Kernel: arch/arm/boot/zImage is ready" is
displayed twice, and a broken uImage is created.
The same problem could happen on bootpImage.
This commit adds dependencies among Image, zImage, uImage, and
bootpImage to arch/arm/Makefile, which is included from the
top-level Makefile.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The mmap semaphore should not be taken when page faults are disabled.
Since pagefault_disable() no longer disables preemption, we now need
to use faulthandler_disabled() in place of in_atomic().
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Since 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the
real timekeeper last") it has become possible on ARM to:
- Obtain a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE timestamp
via syscall.
- Subsequently obtain a timestamp for the same clock ID via VDSO which
predates the first timestamp (by one jiffy).
This is because ARM's update_vsyscall is deriving the coarse time
using the __current_kernel_time interface, when it should really be
using the timekeeper object provided to it by the timekeeping core.
It happened to work before only because __current_kernel_time would
access the same timekeeper object which had been passed to
update_vsyscall. This is no longer the case.
Cc: stable@vger.kernel.org
Fixes: 906c55579a63 ("timekeeping: Copy the shadow-timekeeper over the real timekeeper last")
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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ret_fast_syscall runs when user space makes a syscall. However it
needs to be marked as such so the ELF information is correct. Before
it was:
101: 8000f300 0 NOTYPE LOCAL DEFAULT 2 ret_fast_syscall
But with this change it correctly shows as:
101: 8000f300 96 FUNC LOCAL DEFAULT 2 ret_fast_syscall
I see this function when using perf to unwind call stacks from kernel
space to user space. Without this change I would need to add some
special case logic when using the vmlinux ELF information.
Signed-off-by: Drew Richardson <drew.richardson@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Since the commit "b2c3e38a5471 ARM: redo TTBR setup code for LPAE",
the setup code had been reworked. As a result the secondary CPUs
failed to come online in Big Endian.
As explained by Russell, the new code expected the value in r4/r5 to
be the least significant 32bits in r4 and the most significant 32bits
in r5. However, in the secondary code, we load this using ldrd, which
on BE reverses that.
This patch swap r4/r5 after the ldrd. It is done using the xor
instructions in order to not use a temporary register.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The Sourcery CodeBench Lite 2014.05 toolchain (gcc 4.8.3, binutils
2.24.51) has a GCC which implements -fuse-ld, and it doesn't include
the gold linker, but it lacks an ld.bfd executable in its
installation. This means that passing -fuse-ld=bfd fails with:
VDSO arch/arm/vdso/vdso.so.raw
collect2: fatal error: cannot find 'ld'
Arguably this is a deficiency in the toolchain, but I suspect it's
commonly used enough that it's worth accommodating: just use
cc-ldoption (to cause a link attempt) instead of cc-option to test
whether we can use -fuse-ld. So -fuse-ld=bfd won't be used with this
toolchain, but the build will rightly succeed, just as it does for
toolchains which don't implement -fuse-ld (and don't use gold as the
default linker).
Note: this will change the failure mode for a corner case I was trying
to handle in d2b30cd4b722, where the toolchain defaults to the gold
linker and the BFD linker is not found in PATH, from:
VDSO arch/arm/vdso/vdso.so.raw
collect2: fatal error: cannot find 'ld'
i.e. the BFD linker is not found, to:
OBJCOPY arch/arm/vdso/vdso.so
BFD: arch/arm/vdso/vdso.so: Not enough room for program headers, try
linking with -N
that is, we fail to prevent gold from being used as the linker, and it
produces an object that objcopy can't digest.
Reported-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Tested-by: Raphaël Poggi <poggi.raph@gmail.com>
Fixes: d2b30cd4b722 ("ARM: 8384/1: VDSO: force use of BFD linker")
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Fengguang Wu reports that building ARM with !MMU results in the
following build error:
arch/arm/kernel/built-in.o: In function `__soft_restart':
>> :(.text+0x1624): undefined reference to `arch_virt_to_idmap'
Fix this by adding an appropriate IS_ENABLED(CONFIG_MMU) into the
__virt_to_idmap() inline function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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We must invalidate the L1 cache before enabling coherency, otherwise
secondary CPUs can inject invalid cache lines into the coherent CPU
cluster, which could then be migrated to other CPUs. This fixes a
recent regression with SoCFPGA randomly failing to boot.
Fixes: 02b4e2756e01 ("ARM: v7 setup function should invalidate L1 cache")
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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nr_bitmaps member of mapping structure stores the number of already
allocated bitmaps and it is interpreted as loop iterator (it starts from
0 not from 1), so a comparison against number of possible bitmap
extensions should include this fact. This patch fixes this by changing
the extension failure condition. This issue has been introduced by
commit 4d852ef8c2544ce21ae41414099a7504c61164a0 ("arm: dma-mapping: Add
support to extend DMA IOMMU mappings").
Reported-by: Hyungwon Hwang <human.hwang@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Hyungwon Hwang <human.hwang@samsung.com>
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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It's possible, albeit unlikely, that using the of_node here will
reference freed memory. Call of_node_put() after printing the
name to be safe.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This patch is to get correct physical address of the reset function for
PAE systems, which use aliased physical memory for booting.
See the "ARM: mm: Introduce virt_to_idmap() with an arch hook" for details.
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This reverts commit dec4f799d0a4c9edae20512fa60b0a36f3299ca2.
Jörg Otte reports a NULL pointder dereference due to this commit, as
'crtc_state' very much can be NULL:
crtc_state = state->base.state ?
intel_atomic_get_crtc_state(state->base.state, intel_crtc) : NULL;
So the change to test 'crtc_state->base.active' cannot possibly be
correct as-is.
There may be some other minimal fix (like just checking crtc_state for
NULL), but I'm just reverting it now for the rc2 release, and people
like Daniel Vetter who actually know this code will figure out what the
right solution is in the longer term.
Reported-and-bisected-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
CC: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Normally opening a file, unlinking it and then closing will have
the inode freed upon close() (provided that it's not otherwise busy and
has no remaining links, of course). However, there's one case where that
does *not* happen. Namely, if you open it by fhandle with cold dcache,
then unlink() and close().
In normal case you get d_delete() in unlink(2) notice that dentry
is busy and unhash it; on the final dput() it will be forcibly evicted from
dcache, triggering iput() and inode removal. In this case, though, we end
up with *two* dentries - disconnected (created by open-by-fhandle) and
regular one (used by unlink()). The latter will have its reference to inode
dropped just fine, but the former will not - it's considered hashed (it
is on the ->s_anon list), so it will stay around until the memory pressure
will finally do it in. As the result, we have the final iput() delayed
indefinitely. It's trivial to reproduce -
void flush_dcache(void)
{
system("mount -o remount,rw /");
}
static char buf[20 * 1024 * 1024];
main()
{
int fd;
union {
struct file_handle f;
char buf[MAX_HANDLE_SZ];
} x;
int m;
x.f.handle_bytes = sizeof(x);
chdir("/root");
mkdir("foo", 0700);
fd = open("foo/bar", O_CREAT | O_RDWR, 0600);
close(fd);
name_to_handle_at(AT_FDCWD, "foo/bar", &x.f, &m, 0);
flush_dcache();
fd = open_by_handle_at(AT_FDCWD, &x.f, O_RDWR);
unlink("foo/bar");
write(fd, buf, sizeof(buf));
system("df ."); /* 20Mb eaten */
close(fd);
system("df ."); /* should've freed those 20Mb */
flush_dcache();
system("df ."); /* should be the same as #2 */
}
will spit out something like
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 322023 303843 1131 100% /
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 322023 303843 1131 100% /
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/root 322023 283282 21692 93% /
- inode gets freed only when dentry is finally evicted (here we trigger
than by remount; normally it would've happened in response to memory
pressure hell knows when).
Cc: stable@vger.kernel.org # v2.6.38+; earlier ones need s/kill_it/unhash_it/
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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when opening a directory we want the overlayfs inode, not one from
the topmost layer.
Reported-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Tested-By: Andrey Jr. Melnikov <temnota.am@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Cc: stable@vger.kernel.org # all branches
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Dan reported that the recent changes to the broadcast code introduced
a potential NULL dereference.
Add the proper check.
Fixes: e0454311903d "tick/broadcast: Sanity check the shutdown of the local clock_event"
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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commit 66fc13039422ba7df2d01a8ee0873e4ef965b50b ("mm: shmem_zero_setup
skip security check and lockdep conflict with XFS") caused a regression
for SELinux by disabling any SELinux checking of mprotect PROT_EXEC on
shared anonymous mappings. However, even before that regression, the
checking on such mprotect PROT_EXEC calls was inconsistent with the
checking on a mmap PROT_EXEC call for a shared anonymous mapping. On a
mmap, the security hook is passed a NULL file and knows it is dealing
with an anonymous mapping and therefore applies an execmem check and no
file checks. On a mprotect, the security hook is passed a vma with a
non-NULL vm_file (as this was set from the internally-created shmem
file during mmap) and therefore applies the file-based execute check
and no execmem check. Since the aforementioned commit now marks the
shmem zero inode with the S_PRIVATE flag, the file checks are disabled
and we have no checking at all on mprotect PROT_EXEC. Add a test to
the mprotect hook logic for such private inodes, and apply an execmem
check in that case. This makes the mmap and mprotect checking
consistent for shared anonymous mappings, as well as for /dev/zero and
ashmem.
Cc: <stable@vger.kernel.org> # 4.1.x
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <pmoore@redhat.com>
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The increased use of pdtlb/pitlb instructions seemed to increase the
frequency of random segmentation faults building packages. Further, we
had a number of cases where TLB inserts would repeatedly fail and all
forward progress would stop. The Haskell ghc package caused a lot of
trouble in this area. The final indication of a race in pte handling was
this syslog entry on sibaris (C8000):
swap_free: Unused swap offset entry 00000004
BUG: Bad page map in process mysqld pte:00000100 pmd:019bbec5
addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
Backtrace:
[<0000000040173eb0>] show_stack+0x20/0x38
[<0000000040444424>] dump_stack+0x9c/0x110
[<00000000402a0d38>] print_bad_pte+0x1a8/0x278
[<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
[<00000000402a4090>] zap_page_range+0xf0/0x198
[<00000000402ba2a4>] SyS_madvise+0x404/0x8c0
Note that the pte value is 0 except for the accessed bit 0x100. This bit
shouldn't be set without the present bit.
It should be noted that the madvise system call is probably a trigger for many
of the random segmentation faults.
In looking at the kernel code, I found the following problems:
1) The pte_clear define didn't take TLB lock when clearing a pte.
2) We didn't test pte present bit inside lock in exception support.
3) The pte and tlb locks needed to merged in order to ensure consistency
between page table and TLB. This also has the effect of serializing TLB
broadcasts on SMP systems.
The attached change implements the above and a few other tweaks to try
to improve performance. Based on the timing code, TLB purges are very
slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
beneficial to test the split_tlb variable to avoid duplicate purges.
Probably, all PA 2.0 machines have combined TLBs.
I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
applications and most threads have a stack size that is too large to
make this useful. I added some comments to this effect.
Since implementing 1 through 3, I haven't had any random segmentation
faults on mx3210 (rp3440) in about one week of building code and running
as a Debian buildd.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v3.18+
Signed-off-by: Helge Deller <deller@gmx.de>
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This patch adds hardware assisted scrolling. The code is based upon the
following investigation: https://parisc.wiki.kernel.org/index.php/NGLE#Blitter
A simple 'time ls -la /usr/bin' test shows 1.6x speed increase over soft
copy and 2.3x increase over FBINFO_READS_FAST (prefer soft copy over
screen redraw) on Artist framebuffer.
Signed-off-by: Alex Ivanov <lausgans@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
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Add support in the NFIT BLK I/O path for the "latch" flag
defined in the "Get Block NVDIMM Flags" _DSM function:
http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf
This flag requires the driver to read back the command register after it
is written in the block I/O path. This ensures that the hardware has
fully processed the new command and moved the aperture appropriately.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Update the nfit block I/O path to use the new PMEM API and to adhere to
the read/write flows outlined in the "NVDIMM Block Window Driver
Writer's Guide":
http://pmem.io/documents/NVDIMM_Driver_Writers_Guide.pdf
This includes adding support for targeted NVDIMM flushes called "flush
hints" in the ACPI 6.0 specification:
http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf
For performance and media durability the mapping for a BLK aperture is
moved to a write-combining mapping which is consistent with
memcpy_to_pmem() and wmb_blk().
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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In preparation for fixing the BLK path to properly use "directed
pcommit" enable the unit test infrastructure to emit mock "flush"
tables. Writes to these flush addresses trigger a memory controller to
flush its internal buffers to persistent media, similar to the x86
"pcommit" instruction.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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The implementation for the new "DIMM Flags" DSM relies on the -ENOTTY
return code to indicate that the flags are unimplimented and to fall
back to a safe default. As is the -ENXIO error code erroneoously
indicates to fail enabling a BLK region.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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In the 4.2-rc1 merge the default_memremap_pmem() implementation switched
from ioremap_nocache() to ioremap_wt(). Add it to the list of mocked
routines to restore the ability to run the unit tests.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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The file include/linux/pmem.h was recently created to hold the PMEM API,
and is logically part of the PMEM driver. Add an entry for this file to
MAINTAINERS.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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This reverts commit 63c4fda3c0bb841b1aad1298fc7fe94058fc79f8 as it
causes issues with detecting 3-finger taps.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=100481
Cc: stable@vger.kernel.org
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
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We currently set x27 in compat_sys_sigreturn_wrapper and
compat_sys_rt_sigreturn_wrapper, similarly to what we do with r8/why on
32-bit ARM, in an attempt to prevent sigreturns from being restarted.
However, on arm64 we have always used pt_regs::syscallno for syscall
restarting (for both native and compat tasks), and x27 is never
inspected again before being overwritten in kernel_exit.
This patch removes the pointless register assignments.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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We were using the native syscall and that results in subtle breakage.
This is the same issue as fixed in 077d0e65618f27b2199d622e12ada6d8f3dbd862
(MIPS: N32: Use compat getsockopt syscall) but that commit did fix it only
for N32.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=100291
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Russell King
Robert Jarzmik
Julien Grall
Ard Biesheuvel
Masahiro Yamada
Nicolas Pitre
Nathan Lynch
Drew Richardson
Gregory CLEMENT
Marek Szyprowski
Stephen Boyd
Vitaly Andrianov
Linus Torvalds
Al Viro
Thomas Gleixner
Stephen Smalley
John David Anglin
Alex Ivanov
Ross Zwisler
Dan Williams
Dmitry Torokhov
Mark Rutland
Ralf Baechle