Fix a slab out of bounds read in keychord_write(), detected by KASAN.
Signed-off-by: Mohan Srinivasan <srmohan@google.com>
Bug: 63962952
Change-Id: Iafef48b5d7283750ac0f39f5aaa767b1c3bf2004
(cherry picked from commit 913d980e07)
Under CONFIG_DEBUG_PREEMPT=y, this_cpu_ptr() ends up calling back into
raw_smp_processor_id(), resulting in some hilariously catastrophic
infinite recursion. In the normal case, we have:
#define this_cpu_ptr(ptr) raw_cpu_ptr(ptr)
and everything is dandy. However for CONFIG_DEBUG_PREEMPT, this_cpu_ptr()
is defined in terms of my_cpu_offset, wherein the fun begins:
#define my_cpu_offset per_cpu_offset(smp_processor_id())
...
#define smp_processor_id() debug_smp_processor_id()
...
notrace unsigned int debug_smp_processor_id(void)
{
return check_preemption_disabled("smp_processor_id", "");
...
notrace static unsigned int check_preemption_disabled(const char *what1,
const char *what2)
{
int this_cpu = raw_smp_processor_id();
and bang. Use raw_cpu_ptr() directly to avoid that.
Fixes: 57c82954e7 ("arm64: make cpu number a percpu variable")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 34a6980c82)
Signed-off-by: John Stultz <john.stultz@linaro.org>
Add missing header linux/sched.h to fix undeclared functions/variables,
otherwise we run into following build error:
CC [M] drivers/tee/optee/rpc.o
drivers/tee/optee/rpc.c: In function 'handle_rpc_func_cmd_wait':
drivers/tee/optee/rpc.c:144:2: error: implicit declaration of function 'set_current_state' [-Werror=implicit-function-declaration]
set_current_state(TASK_INTERRUPTIBLE);
^
drivers/tee/optee/rpc.c:144:20: error: 'TASK_INTERRUPTIBLE' undeclared (first use in this function)
set_current_state(TASK_INTERRUPTIBLE);
^
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Fix module init and core references to use structured layout
defined by lsk-android commit 070663bffb3a ("UPSTREAM: module:
use a structure to encapsulate layout.").
Fixes: LSK commit 229c46f0c7 ("arm64: Kprobes with single stepping support")
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit 24af6c4e4e upstream.
The arm64 module PLT code allocates all PLT entries in a single core
section, since the overhead of having a separate init PLT section is
not justified by the small number of PLT entries usually required for
init code.
However, the core and init module regions are allocated independently,
and there is a corner case where the core region may be allocated from
the VMALLOC region if the dedicated module region is exhausted, but the
init region, being much smaller, can still be allocated from the module
region. This leads to relocation failures if the distance between those
regions exceeds 128 MB. (In fact, this corner case is highly unlikely to
occur on arm64, but the issue has been observed on ARM, whose module
region is much smaller).
So split the core and init PLT regions, and name the latter ".init.plt"
so it gets allocated along with (and sufficiently close to) the .init
sections that it serves. Also, given that init PLT entries may need to
be emitted for branches that target the core module, modify the logic
that disregards defined symbols to only disregard symbols that are
defined in the same section as the relocated branch instruction.
Since there may now be two PLT entries associated with each entry in
the symbol table, we can no longer hijack the symbol::st_size fields
to record the addresses of PLT entries as we emit them for zero-addend
relocations. So instead, perform an explicit comparison to check for
duplicate entries.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit 8244062ef1 upstream.
For CONFIG_KALLSYMS, we keep two symbol tables and two string tables.
There's one full copy, marked SHF_ALLOC and laid out at the end of the
module's init section. There's also a cut-down version that only
contains core symbols and strings, and lives in the module's core
section.
After module init (and before we free the module memory), we switch
the mod->symtab, mod->num_symtab and mod->strtab to point to the core
versions. We do this under the module_mutex.
However, kallsyms doesn't take the module_mutex: it uses
preempt_disable() and rcu tricks to walk through the modules, because
it's used in the oops path. It's also used in /proc/kallsyms.
There's nothing atomic about the change of these variables, so we can
get the old (larger!) num_symtab and the new symtab pointer; in fact
this is what I saw when trying to reproduce.
By grouping these variables together, we can use a
carefully-dereferenced pointer to ensure we always get one or the
other (the free of the module init section is already done in an RCU
callback, so that's safe). We allocate the init one at the end of the
module init section, and keep the core one inside the struct module
itself (it could also have been allocated at the end of the module
core, but that's probably overkill).
Reported-by: Weilong Chen <chenweilong@huawei.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111541
Cc: stable@kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
[AmitP: LTS backport is reverted earlier in lsk-android commit
3f237b5bfda5 ("Revert "modules: fix longstanding /proc/kallsyms vs module insertion race."),
Re-apply the upstream version instead along with related
set of dependent patches.]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit e022441851 upstream.
Currently, percpu symbols from .data..percpu ELF section of a module are
not copied over and stored in final symtab array of struct module.
Consequently such symbol cannot be returned via kallsyms API (for
example kallsyms_lookup_name). This can be especially confusing when the
percpu symbol is exported. Only its __ksymtab et al. are present in its
symtab.
The culprit is in layout_and_allocate() function where SHF_ALLOC flag is
dropped for .data..percpu section. There is in fact no need to copy the
section to final struct module, because kernel module loader allocates
extra percpu section by itself. Unfortunately only symbols from
SHF_ALLOC sections are copied due to a check in is_core_symbol().
The patch changes is_core_symbol() function to copy over also percpu
symbols (their st_shndx points to .data..percpu ELF section). We do it
only if CONFIG_KALLSYMS_ALL is set to be consistent with the rest of the
function (ELF section is SHF_ALLOC but !SHF_EXECINSTR). Finally
elf_type() returns type 'a' for a percpu symbol because its address is
absolute.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit 85c898db63 upstream.
Modules have three sections: text, rodata and writable data. The code
handled the case where these overlapped, however they never can:
debug_align() ensures they are always page-aligned.
This is why we got away with manually traversing the pages in
set_all_modules_text_rw() without rounding.
We create three helper functions: frob_text(), frob_rodata() and
frob_writable_data(). We then call these explicitly at every point,
so it's clear what we're doing.
We also expose module_enable_ro() and module_disable_ro() for
livepatch to use.
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit 7523e4dc50 upstream.
Makes it easier to handle init vs core cleanly, though the change is
fairly invasive across random architectures.
It simplifies the rbtree code immediately, however, while keeping the
core data together in the same cachline (now iff the rbtree code is
enabled).
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit 20ef10c1b3 upstream.
When setting a module's RO and NX permissions, set_section_ro_nx() is
used, but when clearing them, unset_module_{init,core}_ro_nx() are used.
The unset functions don't have the same checks the set function has for
partial page protections. It's probably harmless, but it's still
confusingly asymmetrical.
Instead, use the same logic to do both. Also add some new
set_module_{init,core}_ro_nx() helper functions for more symmetry with
the unset functions.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
This reverts commit 610dde5afb.
Revert this backported upstream commit 8244062ef1.
Will re-apply the upstream version along with other set of patches
and dependencies of upstream commit 24af6c4e4e
("UPSTREAM: arm64: module: split core and init PLT sections").
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
commit 6720a305df upstream.
None of the code actually wants a thread_info, it all wants a
task_struct, and it's just converting back and forth between the two
("ti->task" to get the task_struct from the thread_info, and
"task_thread_info(task)" to go the other way).
No semantic change.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
init_thread_info is deprecated.
See Change-Id: Ia4769ddcc6fc556e9eb6193d64fc99fe2d9e39ab
("UPSTREAM: arm64: thread_info remove stale items").
Use init_task.thread_info instead, to fix following build error:
arch/arm64/kernel/setup.c: In function 'setup_arch':
arch/arm64/kernel/setup.c:356:2: error: 'init_thread_info' undeclared (first use in this function)
init_thread_info.ttbr0 = virt_to_phys(empty_zero_page);
^
Fixes: Change-Id: I85a49f70e13b153b9903851edf56f6531c14e6de
("BACKPORT: arm64: Disable TTBR0_EL1 during normal kernel execution")
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
This can cause issues with processes using the poll()
interface:
1) client sends two oneway transactions
2) the second one gets queued on async_todo
(because the server didn't handle the first one
yet)
3) server returns from poll(), picks up the
first transaction and does transaction work
4) server is done with the transaction, sends
BC_FREE_BUFFER, and the second transaction gets
moved to thread->todo
5) libbinder's handlePolledCommands() only handles
the commands in the current data buffer, so
doesn't see the new transaction
6) the server continues running and issues a new
outgoing transaction. Now, it suddenly finds
the incoming oneway transaction on its thread
todo, and returns that to userspace.
7) userspace does not expect this to happen; it
may be holding a lock while making the outgoing
transaction, and if handling the incoming
trasnaction requires taking the same lock,
userspace will deadlock.
By queueing the async transaction to the proc
workqueue, we make sure it's only picked up when
a thread is ready for proc work.
Bug: 38201220
Bug: 63075553
Bug: 63079216
Change-Id: I84268cc112f735d7e3173793873dfdb4b268468b
Signed-off-by: Martijn Coenen <maco@android.com>
Because we're not guaranteed that subsequent calls
to poll() will have a poll_table_struct parameter
with _qproc set. When _qproc is not set, poll_wait()
is a noop, and we won't be woken up correctly.
Bug: 64552728
Change-Id: I5b904c9886b6b0994d1631a636f5c5e5f6327950
Test: binderLibTest stops hanging with new test
Signed-off-by: Martijn Coenen <maco@android.com>
This allows userspace to request death notifications without
having to worry about getting an immediate callback on the same
thread; one scenario where this would be problematic is if the
death recipient handler grabs a lock that was already taken
earlier (eg as part of a nested transaction).
Bug: 23525545
Test: binderLibTest.DeathNotificationThread passes
Change-Id: I955e16306fe3110dacb9a391ffff1bf869249495
Signed-off-by: Martijn Coenen <maco@android.com>
This patch moves arm64's struct thread_info from the task stack into
task_struct. This protects thread_info from corruption in the case of
stack overflows, and makes its address harder to determine if stack
addresses are leaked, making a number of attacks more difficult. Precise
detection and handling of overflow is left for subsequent patches.
Largely, this involves changing code to store the task_struct in sp_el0,
and acquire the thread_info from the task struct. Core code now
implements current_thread_info(), and as noted in <linux/sched.h> this
relies on offsetof(task_struct, thread_info) == 0, enforced by core
code.
This change means that the 'tsk' register used in entry.S now points to
a task_struct, rather than a thread_info as it used to. To make this
clear, the TI_* field offsets are renamed to TSK_TI_*, with asm-offsets
appropriately updated to account for the structural change.
Userspace clobbers sp_el0, and we can no longer restore this from the
stack. Instead, the current task is cached in a per-cpu variable that we
can safely access from early assembly as interrupts are disabled (and we
are thus not preemptible).
Both secondary entry and idle are updated to stash the sp and task
pointer separately.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This is a modification of Mark Rutland's original patch. Guards to check
if CONFIG_THREAD_INFO_IN_TASK is used has been inserted. get_current()
for when CONFIG_THREAD_INFO_IN_TASK is not used has been added to
arch/arm64/include/asm/current.h.
Bug: 38331309
Change-Id: Ic5eae344a7c2baea0864f6ae16be1e9c60c0a74a
(cherry picked from commit c02433dd6d)
Signed-off-by: Zubin Mithra <zsm@google.com>
Shortly we will want to load a percpu variable in the return from
userspace path. We can save an instruction by folding the addition of
the percpu offset into the load instruction, and this patch adds a new
helper to do so.
At the same time, we clean up this_cpu_ptr for consistency. As with
{adr,ldr,str}_l, we change the template to take the destination register
first, and name this dst. Secondly, we rename the macro to adr_this_cpu,
following the scheme of adr_l, and matching the newly added
ldr_this_cpu.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: Iaaf4ea9674ab89289badee216b5305204172895e
(cherry picked from commit 1b7e2296a8)
Signed-off-by: Zubin Mithra <zsm@google.com>
In the absence of CONFIG_THREAD_INFO_IN_TASK, core code maintains
thread_info::cpu, and low-level architecture code can access this to
build raw_smp_processor_id(). With CONFIG_THREAD_INFO_IN_TASK, core code
maintains task_struct::cpu, which for reasons of hte header soup is not
accessible to low-level arch code.
Instead, we can maintain a percpu variable containing the cpu number.
For both the old and new implementation of raw_smp_processor_id(), we
read a syreg into a GPR, add an offset, and load the result. As the
offset is now larger, it may not be folded into the load, but otherwise
the assembly shouldn't change much.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: I154927b0f9fc0ebbbed88c9958408bbb19cf09de
(cherry picked from commit 57c82954e7)
Signed-off-by: Zubin Mithra <zsm@google.com>
Subsequent patches will make smp_processor_id() use a percpu variable.
This will make smp_processor_id() dependent on the percpu offset, and
thus we cannot use smp_processor_id() to figure out what to initialise
the offset to.
Prepare for this by initialising the percpu offset based on
current::cpu, which will work regardless of how smp_processor_id() is
implemented. Also, make this relationship obvious by placing this code
together at the start of secondary_start_kernel().
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: I43304d06602216fbb5b968ff83e0face11e238f5
(cherry picked from commit 580efaa7cc)
Signed-off-by: Zubin Mithra <zsm@google.com>
When returning from idle, we rely on the fact that thread_info lives at
the end of the kernel stack, and restore this by masking the saved stack
pointer. Subsequent patches will sever the relationship between the
stack and thread_info, and to cater for this we must save/restore sp_el0
explicitly, storing it in cpu_suspend_ctx.
As cpu_suspend_ctx must be doubleword aligned, this leaves us with an
extra slot in cpu_suspend_ctx. We can use this to save/restore tpidr_el1
in the same way, which simplifies the code, avoiding pointer chasing on
the restore path (as we no longer need to load thread_info::cpu followed
by the relevant slot in __per_cpu_offset based on this).
This patch stashes both registers in cpu_suspend_ctx.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 623b476fc8)
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
When CONFIG_THREAD_INFO_IN_TASK is selected, task stacks may be freed
before a task is destroyed. To account for this, the stacks are
refcounted, and when manipulating the stack of another task, it is
necessary to get/put the stack to ensure it isn't freed and/or re-used
while we do so.
This patch reworks the arm64 stack walking code to account for this.
When CONFIG_THREAD_INFO_IN_TASK is not selected these perform no
refcounting, and this should only be a structural change that does not
affect behaviour.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: I89c4f53c4fea0d0be2f88221489c0c7f43366810
(cherry picked from commit 9bbd4c56b0)
Signed-off-by: Zubin Mithra <zsm@google.com>
The walk_stackframe functions is architecture-specific, with a varying
prototype, and common code should not use it directly. None of its
current users can be built as modules. With THREAD_INFO_IN_TASK, users
will also need to hold a stack reference before calling it.
There's no reason for it to be exported, and it's very easy to misuse,
so unexport it for now.
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>
Bug: 38331309
Change-Id: Ibe0dca36cc7d35f92c6bc13b373755d82f0eb9ef
(cherry picked from commit 2020a5ae7c)
Signed-off-by: Zubin Mithra <zsm@google.com>
In arm64's die and __die routines we pass around a thread_info, and
subsequently use this to determine the relevant task_struct, and the end
of the thread's stack. Subsequent patches will decouple thread_info from
the stack, and this approach will no longer work.
To figure out the end of the stack, we can use the new generic
end_of_stack() helper. As we only call __die() from die(), and die()
always deals with the current task, we can remove the parameter and have
both acquire current directly, which also makes it clear that __die
can't be called for arbitrary tasks.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: Ie1a96a0a8e244d458a7f147001b64216403e07c4
(cherry picked from commit 876e7a38e8)
Signed-off-by: Zubin Mithra <zsm@google.com>
We define current_stack_pointer in <asm/thread_info.h>, though other
files and header relying upon it do not have this necessary include, and
are thus fragile to changes in the header soup.
Subsequent patches will affect the header soup such that directly
including <asm/thread_info.h> may result in a circular header include in
some of these cases, so we can't simply include <asm/thread_info.h>.
Instead, factor current_thread_info into its own header, and have all
existing users include this explicitly.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: I4d6bc27bef686d0dade1d6abe1ce947cf6c4dfb3
(cherry picked from commit a9ea0017eb)
Signed-off-by: Zubin Mithra <zsm@google.com>
Subsequent patches will move the thread_info::{task,cpu} fields, and the
current TI_{TASK,CPU} offset definitions are not used anywhere.
This patch removes the redundant definitions.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This is a modification of Mark Rutland's original patch. Guards to
check if CONFIG_THREAD_INFO_IN_TASK is used has been inserted.
Bug: 38331309
Change-Id: I95903e0f862fc5dcf89e51926afa22389f2f7cee
(cherry picked from commit 3fe12da4c7)
Signed-off-by: Zubin Mithra <zsm@google.com>
We have a comment claiming __switch_to() cares about where cpu_context
is located relative to cpu_domain in thread_info. However arm64 has
never had a thread_info::cpu_domain field, and neither __switch_to nor
cpu_switch_to care where the cpu_context field is relative to others.
Additionally, the init_thread_info alias is never used anywhere in the
kernel, and will shortly become problematic when thread_info is moved
into task_struct.
This patch removes both.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: Ia4769ddcc6fc556e9eb6193d64fc99fe2d9e39ab
(cherry picked from commit dcbe02855f)
Signed-off-by: Zubin Mithra <zsm@google.com>
When CONFIG_THREAD_INFO_IN_TASK is selected, the current_thread_info()
macro relies on current having been defined prior to its use. However,
not all users of current_thread_info() include <asm/current.h>, and thus
current is not guaranteed to be defined.
When CONFIG_THREAD_INFO_IN_TASK is not selected, it's possible that
get_current() / current are based upon current_thread_info(), and
<asm/current.h> includes <asm/thread_info.h>. Thus always including
<asm/current.h> would result in circular dependences on some platforms.
To ensure both cases work, this patch includes <asm/current.h>, but only
when CONFIG_THREAD_INFO_IN_TASK is selected.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: Ia981a829798d60a54d4e3eb679d8e24b01228357
(cherry picked from commit dc3d2a679c)
Signed-off-by: Zubin Mithra <zsm@google.com>
Since commit f56141e3e2 ("all arches, signal: move restart_block
to struct task_struct"), thread_info and restart_block have been
logically distinct, yet struct restart_block is still defined in
<linux/thread_info.h>.
At least one architecture (erroneously) uses restart_block as part of
its thread_info, and thus the definition of restart_block must come
before the include of <asm/thread_info>. Subsequent patches in this
series need to shuffle the order of includes and definitions in
<linux/thread_info.h>, and will make this ordering fragile.
This patch moves the definition of restart_block out to its own header.
This serves as generic cleanup, logically separating thread_info and
restart_block, and also makes it easier to avoid fragility.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bug: 38331309
Change-Id: I4283c87072c092179e2b6c02cbf7248b4a1c2d22
(cherry picked from commit 53d74d056a)
Signed-off-by: Zubin Mithra <zsm@google.com>
The INIT_TASK() initializer was similarly confused about the stack vs
thread_info allocation that the allocators had, and that were fixed in
commit b235beea9e ("Clarify naming of thread info/stack allocators").
The task ->stack pointer only incidentally ends up having the same value
as the thread_info, and in fact that will change.
So fix the initial task struct initializer to point to 'init_stack'
instead of 'init_thread_info', and make sure the ia64 definition for
that exists.
This actually makes the ia64 tsk->stack pointer be sensible for the
initial task, but not for any other task. As mentioned in commit
b235beea9e, that whole pointer isn't actually used on ia64, since
task_stack_page() there just points to the (single) allocation.
All the other architectures seem to have copied the 'init_stack'
definition, even if it tended to be generally unusued.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 38331309
Change-Id: Ia96e9225b07e38df2f4af2b9a7eb2aa972d8845a
(cherry picked from commit 7f1a00b6fc)
Signed-off-by: Zubin Mithra <zsm@google.com>
We've had the thread info allocated together with the thread stack for
most architectures for a long time (since the thread_info was split off
from the task struct), but that is about to change.
But the patches that move the thread info to be off-stack (and a part of
the task struct instead) made it clear how confused the allocator and
freeing functions are.
Because the common case was that we share an allocation with the thread
stack and the thread_info, the two pointers were identical. That
identity then meant that we would have things like
ti = alloc_thread_info_node(tsk, node);
...
tsk->stack = ti;
which certainly _worked_ (since stack and thread_info have the same
value), but is rather confusing: why are we assigning a thread_info to
the stack? And if we move the thread_info away, the "confusing" code
just gets to be entirely bogus.
So remove all this confusion, and make it clear that we are doing the
stack allocation by renaming and clarifying the function names to be
about the stack. The fact that the thread_info then shares the
allocation is an implementation detail, and not really about the
allocation itself.
This is a pure renaming and type fix: we pass in the same pointer, it's
just that we clarify what the pointer means.
The ia64 code that actually only has one single allocation (for all of
task_struct, thread_info and kernel thread stack) now looks a bit odd,
but since "tsk->stack" is actually not even used there, that oddity
doesn't matter. It would be a separate thing to clean that up, I
intentionally left the ia64 changes as a pure brute-force renaming and
type change.
Acked-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bug: 38331309
Change-Id: I870b5476fc900c9145134f9dd3ed18a32a490162
(cherry picked from commit b235beea9e)
Signed-off-by: Zubin Mithra <zsm@google.com>
Otherwise, lower_fs->ioctl() fails due to inode_owner_or_capable().
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
Bug: 63260873
Change-Id: I623a6c7c5f8a3cbd7ec73ef89e18ddb093c43805
Because is_spin_locked() always returns false on UP
systems.
Use assert_spin_locked() instead, and remove the
WARN_ON() instances, since those were easy to verify.
Bug: 64073116
Change-Id: I9080991c6d67e91928282a3ee64db23e50c7d66a
Signed-off-by: Martijn Coenen <maco@android.com>
Sometimes we find a target cpu but then we do not use it as
the energy_diff indicates that we would increase energy usage
or not save anything. To offer an additional option for those
cases, we return a second option which is what we would have
selected if the target CPU had not been found. This gives us
another chance to try to save some energy.
Change-Id: I42c4f20aba10e4cf65b51ac4153e2e00e534c8c7
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
In the current EAS group energy calculations, we only use
the idle state of the group as it is right now. This means
that there are times when EAS cannot see that we are about
to remove all utilization from a group which is likely to
result in us being able to idle that entire group.
This is an attempt to detect that situation and at least
allow the energy calculation to include savings in that
scenario, regardless of what we might be able to actually
achieve in the real world. If a cluster or cpu looks like
it will have some idle time available to it, we try to
map the utilization onto an idle state.
Change-Id: I8fcb1e507f65ae6a2c5647eeef75a4bf28c7a0c0
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Before using a task's util_avg signal in EAS, we need to ensure that
it has been synced up to the last_update_time of prev_cpu's root
cfs_rq.
We previously relied on the side effect of wake_cap to do that,
however that does not happen when the waking CPU has the same
capacity as the prev_cpu. Therefore just explicitly call
sync_entity_load_avg. This may result in calling that function twice
within the same select_task_rq_fair, but since last_update_time
hasn't changed the second call will bail out very quickly.
Change-Id: I91f1fcd71dfeb96b7f5b73418f1cf9ac311d4655
Signed-off-by: Brendan Jackman <brendan.jackman@arm.com>
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
If there have misfit task on one CPU, current code does not handle this
situation for nohz idle balance. As result, we can see the misfit task
stays run on little core for long time.
So this patch check if the CPU has misfit task or not. If has misfit
task then kick nohz idle balance so finally can execute active balance.
Change-Id: I117d3b7404296f8de11cb960a87a6b9a54a9f348
Signed-off-by: Leo Yan <leo.yan at linaro.org>
[taken from https://lists.linaro.org/pipermail/eas-dev/2016-September/000551.html]
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
Stale cpu utilization signals can cause havoc for energy-aware systems,
and they are caused by no updates being performed for cpus which have
no tick running. There is open debate about when is the correct time to
update these cpus, and general recognition that something needs to be
done.
This is an attempt to do something useful.
When we are looking for a task to pull for a newly-idle cpu, we have
an opportunity to update the stats for any cpu which has no tick running
without causing too much disturbance to the system or waking it up.
Change-Id: I0280104ea9c53e56c26f1c56a62bacab5d3e951b
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Brendan Jackman <brendan.jackman@arm.com>
The find_best_target() code has evolved over time to integrate different
micro-optimizations to the point to be quite difficult now to follow
exactly what it's doing.
This patch rafactors the existing code to make it more readable and easy
to maintain. It does that by properly identifying the three main
use-cases and addressing them in priority order:
A) latency sensitive tasks
B) non latency sensitive tasks on IDLE CPUs
C) non latency sensitive tasks on ACTIVE CPUs
The original behaviors are preserved. Some tests to compare
power/performances before and after this patch have been done using
Jankbench and YouTube and we did not noticed sensible differences.
The only difference with respect of the original code is a small update
to favor lower-capacity idle CPUs in case B. The same preference is not
enforce in case A since this can lead to a selection of a non-reserved
CPU for TOP_APP tasks, which ultimately can lead to non desirable
co-scheduling side-effects.
Change-Id: I871e5d95af89176217e4e239b64d44a420baabe8
Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
(removed checkpatch whitespace error)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
