| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
commit c7858bf16c0b2cc62f475f31e6df28c3a68da1d6 upstream.
The asm-prototypes.h file is used to provide dummy function declarations
for genksyms, when processing asm files with EXPORT_SYMBOL. Make sure
that any architecture defines get out of our way. x86 currently has an
issue with memcpy on 64bit with CONFIG_KMEMCHECK=y and with
memset/__memset on 32bit:
$ cat init/test.c
#include <asm/asm-prototypes.h>
$ make -s init/test.o
In file included from ./arch/x86/include/asm/string.h:4:0,
from ./include/linux/string.h:18,
from ./include/linux/bitmap.h:8,
from ./include/linux/cpumask.h:11,
from ./arch/x86/include/asm/cpumask.h:4,
from ./arch/x86/include/asm/msr.h:10,
from ./arch/x86/include/asm/processor.h:20,
from ./arch/x86/include/asm/cpufeature.h:4,
from ./arch/x86/include/asm/thread_info.h:52,
from ./include/linux/thread_info.h:25,
from ./arch/x86/include/asm/preempt.h:6,
from ./include/linux/preempt.h:59,
from ./include/linux/spinlock.h:50,
from ./include/linux/seqlock.h:35,
from ./include/linux/time.h:5,
from ./include/uapi/linux/timex.h:56,
from ./include/linux/timex.h:56,
from ./include/linux/sched.h:19,
from ./include/linux/uaccess.h:4,
from ./arch/x86/include/asm/asm-prototypes.h:2,
from init/test.c:1:
./arch/x86/include/asm/string_64.h:52:47: error: expected declaration specifiers or ‘...’ before ‘(’ token
#define memcpy(dst, src, len) __inline_memcpy((dst), (src), (len))
./include/asm-generic/asm-prototypes.h:6:14: note: in expansion of macro ‘memcpy’
extern void *memcpy(void *, const void *, __kernel_size_t);
^
...
During real build, this manifests itself by genksyms segfaulting.
Fixes: 334bb7738764 ("x86/kbuild: enable modversions for symbols exported from asm")
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Cc: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Michal Marek <mmarek@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 4377748c7b5187c3342a60fa2ceb60c8a57a8488 ]
drivers/hwmon/amd_energy.c:195:15: error: invalid operands to binary expression ('void' and 'int')
(channel - data->nr_cpus));
~~~~~~~~~^~~~~~~~~~~~~~~~~
include/asm-generic/topology.h:51:42: note: expanded from macro 'cpumask_of_node'
#define cpumask_of_node(node) ((void)node, cpu_online_mask)
^~~~
include/linux/cpumask.h:618:72: note: expanded from macro 'cpumask_first_and'
#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
^~~~~
Fixes: f0b848ce6fe9 ("cpumask: Introduce cpumask_of_{node,pcibus} to replace {node,pcibus}_to_cpumask")
Fixes: 8abee9566b7e ("hwmon: Add amd_energy driver to report energy counters")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/20200527134623.930247-1-arnd@arndb.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 2e636d5e66c35dfcbaf617aa8fa963f6847478fe upstream.
Vikram reported that his ARM64 compiler managed to 'optimize' away the
preempt_count manipulations in code like:
preempt_enable_no_resched();
put_user();
preempt_disable();
Irrespective of that fact that that is horrible code that should be
fixed for many reasons, it does highlight a deficiency in the generic
preempt_count manipulators. As it is never right to combine/elide
preempt_count manipulations like this.
Therefore sprinkle some volatile in the two generic accessors to
ensure the compiler is aware of the fact that the preempt_count is
observed outside of the regular program-order view and thus cannot be
optimized away like this.
x86; the only arch not using the generic code is not affected as we
do all this in asm in order to use the segment base per-cpu stuff.
Reported-by: Vikram Mulukutla <markivx@codeaurora.org>
Tested-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: a787870924db ("sched, arch: Create asm/preempt.h")
Link: http://lkml.kernel.org/r/20160516131751.GH3205@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 2a4daadd4d3e507138f8937926e6a4df49c6bfdc ]
Older versions of Libreboot and Coreboot had an invalid value
(`3' in my case) in the century byte affecting the GM45 in
the Thinkpad X200. Not everybody's updated their firmwares,
and Linux <= 4.2 was able to read the RTC without problems,
so workaround this by ignoring invalid values.
Fixes: 3c217e51d8a272b9 ("rtc: cmos: century support")
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Sylvain Chouleur <sylvain.chouleur@intel.com>
Cc: Patrick McDermott <patrick.mcdermott@libiquity.com>
Cc: linux-rtc@vger.kernel.org
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 3c047057d1206ec0f3b88c7809cacba478067a0c upstream.
When CONFIG_BUG is disabled, BUG_ON() will only evaluate the condition,
but will not actually stop the current thread. GCC warns about a couple
of BUG_ON() users where this actually leads to further undefined
behavior:
include/linux/ceph/osdmap.h: In function 'ceph_can_shift_osds':
include/linux/ceph/osdmap.h:54:1: warning: control reaches end of non-void function
fs/ext4/inode.c: In function 'ext4_map_blocks':
fs/ext4/inode.c:548:5: warning: 'retval' may be used uninitialized in this function
drivers/mfd/db8500-prcmu.c: In function 'prcmu_config_clkout':
drivers/mfd/db8500-prcmu.c:762:10: warning: 'div_mask' may be used uninitialized in this function
drivers/mfd/db8500-prcmu.c:769:13: warning: 'mask' may be used uninitialized in this function
drivers/mfd/db8500-prcmu.c:757:7: warning: 'bits' may be used uninitialized in this function
drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq':
drivers/tty/serial/8250/8250_core.c:252:18: warning: 'i' may be used uninitialized in this function
drivers/tty/serial/8250/8250_core.c:235:19: note: 'i' was declared here
There is an obvious conflict of interest here: on the one hand, someone
who disables CONFIG_BUG() will want the kernel to be as small as possible
and doesn't care about printing error messages to a console that nobody
looks at. On the other hand, running into a BUG_ON() condition means that
something has gone wrong, and we probably want to also stop doing things
that might cause data corruption.
This patch picks the second choice, and changes the NOP to BUG(), which
normally stops the execution of the current thread in some form (endless
loop or a trap). This follows the logic we applied in a4b5d580e078 ("bug:
Make BUG() always stop the machine").
For ARM multi_v7_defconfig, the size slightly increases:
section CONFIG_BUG=y CONFIG_BUG=n CONFIG_BUG=n+patch
.text 8320248 | 8180944 | 8207688
.rodata 3633720 | 3567144 | 3570648
__bug_table 32508 | --- | ---
__modver 692 | 1584 | 2176
.init.text 558132 | 548300 | 550088
.exit.text 12380 | 12256 | 12380
.data 1016672 | 1016064 | 1016128
Total 14622556 | 14374510 | 14407326
So instead of saving 1.70% of the total image size, we only save 1.48%
by turning off CONFIG_BUG, but in return we can ensure that we don't run
into cases of uninitialized variable or return code uses when something
bad happens. Aside from that, we significantly reduce the number of
warnings in randconfig builds, which makes it easier to fix the warnings
about other problems.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit cbedfe11347fe418621bd188d58a206beb676218 ]
Commit d66acc39c7ce ("bitops: Optimise get_order()") introduced a
compilation warning because "rx_frag_size" is an "ushort" while
PAGE_SHIFT here is 16.
The commit changed the get_order() to be a multi-line macro where
compilers insist to check all statements in the macro even when
__builtin_constant_p(rx_frag_size) will return false as "rx_frag_size"
is a module parameter.
In file included from ./arch/powerpc/include/asm/page_64.h:107,
from ./arch/powerpc/include/asm/page.h:242,
from ./arch/powerpc/include/asm/mmu.h:132,
from ./arch/powerpc/include/asm/lppaca.h:47,
from ./arch/powerpc/include/asm/paca.h:17,
from ./arch/powerpc/include/asm/current.h:13,
from ./include/linux/thread_info.h:21,
from ./arch/powerpc/include/asm/processor.h:39,
from ./include/linux/prefetch.h:15,
from drivers/net/ethernet/emulex/benet/be_main.c:14:
drivers/net/ethernet/emulex/benet/be_main.c: In function 'be_rx_cqs_create':
./include/asm-generic/getorder.h:54:9: warning: comparison is always
true due to limited range of data type [-Wtype-limits]
(((n) < (1UL << PAGE_SHIFT)) ? 0 : \
^
drivers/net/ethernet/emulex/benet/be_main.c:3138:33: note: in expansion
of macro 'get_order'
adapter->big_page_size = (1 << get_order(rx_frag_size)) * PAGE_SIZE;
^~~~~~~~~
Fix it by moving all of this multi-line macro into a proper function,
and killing __get_order() off.
[akpm@linux-foundation.org: remove __get_order() altogether]
[cai@lca.pw: v2]
Link: http://lkml.kernel.org/r/1564000166-31428-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/1563914986-26502-1-git-send-email-cai@lca.pw
Fixes: d66acc39c7ce ("bitops: Optimise get_order()")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: James Y Knight <jyknight@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 173a3efd3edb2ef6ef07471397c5f542a360e9c1 ]
Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.
In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.
A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return. I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.
The files that saw the largest change from this had these frame sizes
before, and much less with my patch:
fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]
In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:
block/cfq-iosched.c: In function 'cfq_async_queue_prio':
block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
include/linux/dmaengine.h: In function 'dma_maxpq':
include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]
This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.
I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.
Vineet said:
: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2. bloat-o-meter reports code size improvements as gcc elides the
: generated code for stack return.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc]
Tested-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc]
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ removed cris changes - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 3694bd76781b76c4f8d2ecd85018feeb1609f0e5 ]
Currently __set_fixmap_offset is a macro function which has a local
variable called 'addr'. If a caller passes a 'phys' parameter which is
derived from a variable also called 'addr', the local variable will
shadow this, and the compiler will complain about the use of an
uninitialized variable. To avoid the issue with namespace clashes,
'addr' is prefixed with a liberal sprinkling of underscores.
Turning __set_fixmap_offset into a static inline breaks the build for
several architectures. Fixing this properly requires updates to a number
of architectures to make them agree on the prototype of __set_fixmap (it
could be done as a subsequent patch series).
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
[catalin.marinas@arm.com: squashed the original function patch and macro fixup]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream.
The following kernel panic was observed on ARM64 platform due to a stale
TLB entry.
1. ioremap with 4K size, a valid pte page table is set.
2. iounmap it, its pte entry is set to 0.
3. ioremap the same address with 2M size, update its pmd entry with
a new value.
4. CPU may hit an exception because the old pmd entry is still in TLB,
which leads to a kernel panic.
Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page
table") has addressed this panic by falling to pte mappings in the above
case on ARM64.
To support pmd mappings in all cases, TLB purge needs to be performed
in this case on ARM64.
Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page()
so that TLB purge can be added later in seprate patches.
[toshi.kani@hpe.com: merge changes, rewrite patch description]
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 6c26fcd2abfe0a56bbd95271fce02df2896cfd24 upstream.
pfn_modify_allowed() and arch_has_pfn_modify_check() are outside of the
!__ASSEMBLY__ section in include/asm-generic/pgtable.h, which confuses
assembler on archs that don't have __HAVE_ARCH_PFN_MODIFY_ALLOWED (e.g.
ia64) and breaks build:
include/asm-generic/pgtable.h: Assembler messages:
include/asm-generic/pgtable.h:538: Error: Unknown opcode `static inline bool pfn_modify_allowed(unsigned long pfn,pgprot_t prot)'
include/asm-generic/pgtable.h:540: Error: Unknown opcode `return true'
include/asm-generic/pgtable.h:543: Error: Unknown opcode `static inline bool arch_has_pfn_modify_check(void)'
include/asm-generic/pgtable.h:545: Error: Unknown opcode `return false'
arch/ia64/kernel/entry.S:69: Error: `mov' does not fit into bundle
Move those two static inlines into the !__ASSEMBLY__ section so that they
don't confuse the asm build pass.
Fixes: 42e4089c7890 ("x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[groeck: Context changes]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
|
|
commit 42e4089c7890725fcd329999252dc489b72f2921 upstream
For L1TF PROT_NONE mappings are protected by inverting the PFN in the page
table entry. This sets the high bits in the CPU's address space, thus
making sure to point to not point an unmapped entry to valid cached memory.
Some server system BIOSes put the MMIO mappings high up in the physical
address space. If such an high mapping was mapped to unprivileged users
they could attack low memory by setting such a mapping to PROT_NONE. This
could happen through a special device driver which is not access
protected. Normal /dev/mem is of course access protected.
To avoid this forbid PROT_NONE mappings or mprotect for high MMIO mappings.
Valid page mappings are allowed because the system is then unsafe anyways.
It's not expected that users commonly use PROT_NONE on MMIO. But to
minimize any impact this is only enforced if the mapping actually refers to
a high MMIO address (defined as the MAX_PA-1 bit being set), and also skip
the check for root.
For mmaps this is straight forward and can be handled in vm_insert_pfn and
in remap_pfn_range().
For mprotect it's a bit trickier. At the point where the actual PTEs are
accessed a lot of state has been changed and it would be difficult to undo
on an error. Since this is a uncommon case use a separate early page talk
walk pass for MMIO PROT_NONE mappings that checks for this condition
early. For non MMIO and non PROT_NONE there are no changes.
[dwmw2: Backport to 4.9]
[groeck: Backport to 4.4]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit c58f0bb77ed8bf93dfdde762b01cb67eebbdfc29 ]
Patch series "Do not lose dirty bit on THP pages", v4.
Vlastimil noted that pmdp_invalidate() is not atomic and we can lose
dirty and access bits if CPU sets them after pmdp dereference, but
before set_pmd_at().
The bug can lead to data loss, but the race window is tiny and I haven't
seen any reports that suggested that it happens in reality. So I don't
think it worth sending it to stable.
Unfortunately, there's no way to address the issue in a generic way. We
need to fix all architectures that support THP one-by-one.
All architectures that have THP supported have to provide atomic
pmdp_invalidate() that returns previous value.
If generic implementation of pmdp_invalidate() is used, architecture
needs to provide atomic pmdp_estabish().
pmdp_estabish() is not used out-side generic implementation of
pmdp_invalidate() so far, but I think this can change in the future.
This patch (of 12):
This is an implementation of pmdp_establish() that is only suitable for
an architecture that doesn't have hardware dirty/accessed bits. In this
case we can't race with CPU which sets these bits and non-atomic
approach is fine.
Link: http://lkml.kernel.org/r/20171213105756.69879-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Daney <david.daney@cavium.com>
Cc: David Miller <davem@davemloft.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nitin Gupta <nitin.m.gupta@oracle.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.
There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.
Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.
This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.
And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.
Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390]
Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker <dalias@libc.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn <jonas@southpole.se>
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Stafford Horne <shorne@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson <rth@twiddle.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit b6bdb7517c3d3f41f20e5c2948d6bc3f8897394e upstream.
On architectures with CONFIG_HAVE_ARCH_HUGE_VMAP set, ioremap() may
create pud/pmd mappings. A kernel panic was observed on arm64 systems
with Cortex-A75 in the following steps as described by Hanjun Guo.
1. ioremap a 4K size, valid page table will build,
2. iounmap it, pte0 will set to 0;
3. ioremap the same address with 2M size, pgd/pmd is unchanged,
then set the a new value for pmd;
4. pte0 is leaked;
5. CPU may meet exception because the old pmd is still in TLB,
which will lead to kernel panic.
This panic is not reproducible on x86. INVLPG, called from iounmap,
purges all levels of entries associated with purged address on x86. x86
still has memory leak.
The patch changes the ioremap path to free unmapped page table(s) since
doing so in the unmap path has the following issues:
- The iounmap() path is shared with vunmap(). Since vmap() only
supports pte mappings, making vunmap() to free a pte page is an
overhead for regular vmap users as they do not need a pte page freed
up.
- Checking if all entries in a pte page are cleared in the unmap path
is racy, and serializing this check is expensive.
- The unmap path calls free_vmap_area_noflush() to do lazy TLB purges.
Clearing a pud/pmd entry before the lazy TLB purges needs extra TLB
purge.
Add two interfaces, pud_free_pmd_page() and pmd_free_pte_page(), which
clear a given pud/pmd entry and free up a page for the lower level
entries.
This patch implements their stub functions on x86 and arm64, which work
as workaround.
[akpm@linux-foundation.org: fix typo in pmd_free_pte_page() stub]
Link: http://lkml.kernel.org/r/20180314180155.19492-2-toshi.kani@hpe.com
Fixes: e61ce6ade404e ("mm: change ioremap to set up huge I/O mappings")
Reported-by: Lei Li <lious.lilei@hisilicon.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Wang Xuefeng <wxf.wang@hisilicon.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ tweak arm64 portion to rely on CONFIG_ARCH_HAVE_HUGE_VMAP - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 22823ab419d8ed884195cfa75483fd3a99bb1462 upstream.
Add asm-usable variants of EXPORT_SYMBOL/EXPORT_SYMBOL_GPL. This
commit just adds the default implementation; most of the architectures
can simply add export.h to asm/Kbuild and start using <asm/export.h>
from assembler. The rest needs to have their <asm/export.h> define
everal macros and then explicitly include <asm-generic/export.h>
One area where the things might diverge from default is the alignment;
normally it's 8 bytes on 64bit targets and 4 on 32bit ones, both for
unsigned long and for struct kernel_symbol. Unfortunately, amd64 and
m68k are unusual - m68k aligns to 2 bytes (for both) and amd64 aligns
struct kernel_symbol to 16 bytes. For those we'll need asm/export.h to
override the constants used by generic version - KSYM_ALIGN and KCRC_ALIGN
for kernel_symbol and unsigned long resp. And no, __alignof__ would not
do the trick - on amd64 __alignof__ of struct kernel_symbol is 8, not 16.
More serious source of unpleasantness is treatment of function
descriptors on architectures that have those. Things like ppc64,
parisc, ia64, etc. need more than the address of the first insn to
call an arbitrary function. As the result, their representation of
pointers to functions is not the typical "address of the entry point" -
it's an address of a small static structure containing all the required
information (including the entry point, of course). Sadly, the asm-side
conventions differ in what the function name refers to - entry point or
the function descriptor. On ppc64 we do the latter;
bar: .quad foo
is what void (*bar)(void) = foo; turns into and the rare places where
we need to explicitly work with the label of entry point are dealt with
as DOTSYM(foo). For our purposes it's ideal - generic macros are usable.
However, parisc would have foo and P%foo used for label of entry point
and address of the function descriptor and
bar: .long P%foo
woudl be used instead. ia64 goes similar to parisc in that respect,
except that there it's @fptr(foo) rather than P%foo. Such architectures
need to define KSYM_FUNC that would turn a function name into whatever
is needed to refer to function descriptor.
What's more, on such architectures we need to know whether we are exporting
a function or an object - in assembler we have to tell that explicitly, to
decide whether we want EXPORT_SYMBOL(foo) produce e.g.
__ksymtab_foo: .quad foo
or
__ksymtab_foo: .quad @fptr(foo)
For that reason we introduce EXPORT_DATA_SYMBOL{,_GPL}(), to be used for
exports of data objects. On normal architectures it's the same thing
as EXPORT_SYMBOL{,_GPL}(), but on parisc-like ones they differ and the
right one needs to be used. Most of the exports are functions, so we
keep EXPORT_SYMBOL for those...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Razvan Ghitulete <rga@amazon.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 334bb773876403eae3457d81be0b8ea70f8e4ccc upstream.
Commit 4efca4ed ("kbuild: modversions for EXPORT_SYMBOL() for asm") adds
modversion support for symbols exported from asm files. Architectures
must include C-style declarations for those symbols in asm/asm-prototypes.h
in order for them to be versioned.
Add these declarations for x86, and an architecture-independent file that
can be used for common symbols.
With f27c2f6 reverting 8ab2ae6 ("default exported asm symbols to zero") we
produce a scary warning on x86, this commit fixes that.
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Tested-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Peter Wu <peter@lekensteyn.nl>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Razvan Ghitulete <rga@amazon.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
While trying to get our gold link to work, four cleanups:
matched the gdt_page declaration to its definition;
in fiddling unsuccessfully with PERCPU_INPUT(), lined up backslashes;
lined up the backslashes according to convention in percpu-defs.h;
deleted the unused irq_stack_pointer addition to irq_stack_union.
Sad to report that aligning backslashes does not appear to help gold
align to 8192: but while these did not help, they are worth keeping.
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
This patch introduces our implementation of KAISER (Kernel Address Isolation to
have Side-channels Efficiently Removed), a kernel isolation technique to close
hardware side channels on kernel address information.
More information about the patch can be found on:
https://github.com/IAIK/KAISER
From: Richard Fellner <richard.fellner@student.tugraz.at>
From: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
X-Subject: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
Date: Thu, 4 May 2017 14:26:50 +0200
Link: http://marc.info/?l=linux-kernel&m=149390087310405&w=2
Kaiser-4.10-SHA1: c4b1831d44c6144d3762ccc72f0c4e71a0c713e5
To: <linux-kernel@vger.kernel.org>
To: <kernel-hardening@lists.openwall.com>
Cc: <clementine.maurice@iaik.tugraz.at>
Cc: <moritz.lipp@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Richard Fellner <richard.fellner@student.tugraz.at>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <kirill.shutemov@linux.intel.com>
Cc: <anders.fogh@gdata-adan.de>
After several recent works [1,2,3] KASLR on x86_64 was basically
considered dead by many researchers. We have been working on an
efficient but effective fix for this problem and found that not mapping
the kernel space when running in user mode is the solution to this
problem [4] (the corresponding paper [5] will be presented at ESSoS17).
With this RFC patch we allow anybody to configure their kernel with the
flag CONFIG_KAISER to add our defense mechanism.
If there are any questions we would love to answer them.
We also appreciate any comments!
Cheers,
Daniel (+ the KAISER team from Graz University of Technology)
[1] http://www.ieee-security.org/TC/SP2013/papers/4977a191.pdf
[2] https://www.blackhat.com/docs/us-16/materials/us-16-Fogh-Using-Undocumented-CPU-Behaviour-To-See-Into-Kernel-Mode-And-Break-KASLR-In-The-Process.pdf
[3] https://www.blackhat.com/docs/us-16/materials/us-16-Jang-Breaking-Kernel-Address-Space-Layout-Randomization-KASLR-With-Intel-TSX.pdf
[4] https://github.com/IAIK/KAISER
[5] https://gruss.cc/files/kaiser.pdf
[patch based also on
https://raw.githubusercontent.com/IAIK/KAISER/master/KAISER/0001-KAISER-Kernel-Address-Isolation.patch]
Signed-off-by: Richard Fellner <richard.fellner@student.tugraz.at>
Signed-off-by: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Signed-off-by: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Signed-off-by: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 8f235d1a3eb7198affe7cadf676a10afb8a46a1a upstream.
__phys_to_pfn and __pfn_to_phys are symmetric, PHYS_PFN and PFN_PHYS are
semmetric:
- y = (phys_addr_t)x << PAGE_SHIFT
- y >> PAGE_SHIFT = (phys_add_t)x
- (unsigned long)(y >> PAGE_SHIFT) = x
[akpm@linux-foundation.org: use macro arg name `x']
[arnd@arndb.de: include linux/pfn.h for PHYS_PFN definition]
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcin Nowakowski <marcin.nowakowski@mips.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit e88d62cd4b2f0b1ae55e9008e79c2794b1fc914d upstream.
As raw_cpu_generic_read() is a plain read from a raw_cpu_ptr() address,
it's possible (albeit unlikely) that the compiler will split the access
across multiple instructions.
In this_cpu_generic_read() we disable preemption but not interrupts
before calling raw_cpu_generic_read(). Thus, an interrupt could be taken
in the middle of the split load instructions. If a this_cpu_write() or
RMW this_cpu_*() op is made to the same variable in the interrupt
handling path, this_cpu_read() will return a torn value.
For native word types, we can avoid tearing using READ_ONCE(), but this
won't work in all cases (e.g. 64-bit types on most 32-bit platforms).
This patch reworks this_cpu_generic_read() to use READ_ONCE() where
possible, otherwise falling back to disabling interrupts.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pranith Kumar <bobby.prani@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
[Mark: backport to v4.4.y]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit b339752d054fb32863418452dff350a1086885b1 upstream.
When !NUMA, cpumask_of_node(@node) equals cpu_online_mask regardless of
@node. The assumption seems that if !NUMA, there shouldn't be more than
one node and thus reporting cpu_online_mask regardless of @node is
correct. However, that assumption was broken years ago to support
DISCONTIGMEM and whether a system has multiple nodes or not is
separately controlled by NEED_MULTIPLE_NODES.
This means that, on a system with !NUMA && NEED_MULTIPLE_NODES,
cpumask_of_node() will report cpu_online_mask for all possible nodes,
indicating that the CPUs are associated with multiple nodes which is an
impossible configuration.
This bug has been around forever but doesn't look like it has caused any
noticeable symptoms. However, it triggers a WARN recently added to
workqueue to verify NUMA affinity configuration.
Fix it by reporting empty cpumask on non-zero nodes if !NUMA.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 2545e5da080b4839dd859e3b09343a884f6ab0e3 upstream.
... in all cases, including the failing access_ok()
Note that some architectures using asm-generic/uaccess.h have
__copy_from_user() not zeroing the tail on failure halfway
through. This variant works either way.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 9ad18b75c2f6e4a78ce204e79f37781f8815c0fa upstream.
both for access_ok() failures and for faults halfway through
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit e41f501d391265ff568f3e49d6128cc30856a36f upstream.
If CONFIG_KASAN is enabled and gcc is configured with
--disable-initfini-array and/or gold linker is used, gcc emits
.ctors/.dtors and .text.startup/.text.exit sections instead of
.init_array/.fini_array. .dtors section is not explicitly accounted in
the linker script and messes vvar/percpu layout.
We want:
ffffffff822bfd80 D _edata
ffffffff822c0000 D __vvar_beginning_hack
ffffffff822c0000 A __vvar_page
ffffffff822c0080 0000000000000098 D vsyscall_gtod_data
ffffffff822c1000 A __init_begin
ffffffff822c1000 D init_per_cpu__irq_stack_union
ffffffff822c1000 A __per_cpu_load
ffffffff822d3000 D init_per_cpu__gdt_page
We got:
ffffffff8279a600 D _edata
ffffffff8279b000 A __vvar_page
ffffffff8279c000 A __init_begin
ffffffff8279c000 D init_per_cpu__irq_stack_union
ffffffff8279c000 A __per_cpu_load
ffffffff8279e000 D __vvar_beginning_hack
ffffffff8279e080 0000000000000098 D vsyscall_gtod_data
ffffffff827ae000 D init_per_cpu__gdt_page
This happens because __vvar_page and .vvar get different addresses in
arch/x86/kernel/vmlinux.lds.S:
. = ALIGN(PAGE_SIZE);
__vvar_page = .;
.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
/* work around gold bug 13023 */
__vvar_beginning_hack = .;
Discard .dtors/.fini_array/.text.exit, since we don't call dtors.
Merge .text.startup into init text.
Link: http://lkml.kernel.org/r/1467386363-120030-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 2c610022711675ee908b903d242f0b90e1db661f upstream.
While this prior commit:
54cf809b9512 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()")
... fixes spin_is_locked() and spin_unlock_wait() for the usage
in ipc/sem and netfilter, it does not in fact work right for the
usage in task_work and futex.
So while the 2 locks crossed problem:
spin_lock(A) spin_lock(B)
if (!spin_is_locked(B)) spin_unlock_wait(A)
foo() foo();
... works with the smp_mb() injected by both spin_is_locked() and
spin_unlock_wait(), this is not sufficient for:
flag = 1;
smp_mb(); spin_lock()
spin_unlock_wait() if (!flag)
// add to lockless list
// iterate lockless list
... because in this scenario, the store from spin_lock() can be delayed
past the load of flag, uncrossing the variables and loosing the
guarantee.
This patch reworks spin_is_locked() and spin_unlock_wait() to work in
both cases by exploiting the observation that while the lock byte
store can be delayed, the contender must have registered itself
visibly in other state contained in the word.
It also allows for architectures to override both functions, as PPC
and ARM64 have an additional issue for which we currently have no
generic solution.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Giovanni Gherdovich <ggherdovich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: 54cf809b9512 ("locking,qspinlock: Fix spin_is_locked() and spin_unlock_wait()")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit ca9eb49aa9562eaadf3cea071ec7018ad6800425 upstream.
The generic copy_siginfo() is currently defined in
asm-generic/siginfo.h, after including uapi/asm-generic/siginfo.h which
defines the generic struct siginfo. However this makes it awkward for an
architecture to use it if it has to define its own struct siginfo (e.g.
MIPS and potentially IA64), since it means that asm-generic/siginfo.h
can only be included after defining the arch-specific siginfo, which may
be problematic if the arch-specific definition needs definitions from
uapi/asm-generic/siginfo.h.
It is possible to work around this by first including
uapi/asm-generic/siginfo.h to get the constants before defining the
arch-specific siginfo, and include asm-generic/siginfo.h after. However
uapi headers can't be included by other uapi headers, so that first
include has to be in an ifdef __kernel__, with the non __kernel__ case
including the non-UAPI header instead.
Instead of that mess, move the generic copy_siginfo() definition into
linux/signal.h, which allows an arch-specific uapi/asm/siginfo.h to
include asm-generic/siginfo.h and define the arch-specific siginfo, and
for the generic copy_siginfo() to see that arch-specific definition.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Petr Malat <oss@malat.biz>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Christopher Ferris <cferris@google.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12478/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
commit 54cf809b9512be95f53ed4a5e3b631d1ac42f0fa upstream.
Similar to commits:
51d7d5205d33 ("powerpc: Add smp_mb() to arch_spin_is_locked()")
d86b8da04dfa ("arm64: spinlock: serialise spin_unlock_wait against concurrent lockers")
qspinlock suffers from the fact that the _Q_LOCKED_VAL store is
unordered inside the ACQUIRE of the lock.
And while this is not a problem for the regular mutual exclusive
critical section usage of spinlocks, it breaks creative locking like:
spin_lock(A) spin_lock(B)
spin_unlock_wait(B) if (!spin_is_locked(A))
do_something() do_something()
In that both CPUs can end up running do_something at the same time,
because our _Q_LOCKED_VAL store can drop past the spin_unlock_wait()
spin_is_locked() loads (even on x86!!).
To avoid making the normal case slower, add smp_mb()s to the less used
spin_unlock_wait() / spin_is_locked() side of things t |
