The old implementation assumed that SP at the time of __switch_to() is
right above pt_regs which is almost certainly not the case as there will
be some stack build up between entry into kernel and leading up to
__switch_to
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
/proc/<pid>/maps currently don't annotate stack vma with "[stack]"
This is because KSTK_ESP ie expected to return usermode SP of tsk while
currently it returns the kernel mode SP of a sleeping tsk.
While the fix is trivial, we also need to adjust the ARC kernel stack
unwinder to not use KSTK_SP and friends any more.
Cc: <stable@vger.kernel.org>
Reported-and-suggested-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The arc unwinder can also be used for perf callchains.
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull ARC updates from Vineet Gupta:
"Some fixes, nothing too exciting this time as well..."
* tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
ARC: Fix earlycon build breakage
ARC: Dynamically determine BASE_BAUD from DeviceTree
arc: Remove unused prepare_to_copy()
ARC: use ACCESS_ONCE in cmpxchg loop
ARC: add some more comments to ret_from_fork
ARC: fix /proc/cpuinfo for offline cpus
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target. This is because the
restart_block is held in the same memory allocation as the kernel stack.
Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.
Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.
It's also a decent simplification, since the restart code is more or less
identical on all architectures.
[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ffb7fcd66f ("ARC: Dynamically determine BASE_BAUD from DeviceTree")
breaks arc:defconfig build:
drivers/built-in.o: In function `of_setup_earlycon':
(.init.text+0xb3e): undefined reference to `arc_early_base_baud'
drivers/built-in.o: In function `setup_earlycon':
(.init.text+0xcd0): undefined reference to `arc_early_base_baud'
make: *** [vmlinux] Error 1
BASE_BAUD is only required for earlycon, which should depend on
CONFIG_SERIAL_EARLYCON.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull weak function declaration removal from Bjorn Helgaas:
"The "weak" attribute is commonly used for the default version of a
function, where an architecture can override it by providing a strong
version.
Some header file declarations included the "weak" attribute. That's
error-prone because it causes every implementation to be weak, with no
strong version at all, and the linker chooses one based on link order.
What we want is the "weak" attribute only on the *definition* of the
default implementation. These changes remove "weak" from the
declarations, leaving it on the default definitions"
* tag 'remove-weak-declarations' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
uprobes: Remove "weak" from function declarations
memory-hotplug: Remove "weak" from memory_block_size_bytes() declaration
kgdb: Remove "weak" from kgdb_arch_pc() declaration
ARC: kgdb: generic kgdb_arch_pc() suffices
vmcore: Remove "weak" from function declarations
clocksource: Remove "weak" from clocksource_default_clock() declaration
x86, intel-mid: Remove "weak" from function declarations
audit: Remove "weak" from audit_classify_compat_syscall() declaration
The ARC version of kgdb_arch_pc() is identical to the generic version in
kernel/debug/debug_core.c. Drop the ARC version so we use the generic one.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* No active users of this flag anymore
* flag itself was no longer usable with new simualtor which acts just like
hardware, not providing the special chip-id = 0xffff which good old
ISS used to do.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
In light of recent SNAFU with SMP build, allow simple platform to build
as SMP but run UP.
* Remove the dependence on simulation SMP extension to enable quick
build/test iterations of SMP kernel.
* In absence of platform SMP registration, prevent the NULL smp feature
name from borkign the system
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull arch signal handling cleanup from Richard Weinberger:
"This patch series moves all remaining archs to the get_signal(),
signal_setup_done() and sigsp() functions.
Currently these archs use open coded variants of the said functions.
Further, unused parameters get removed from get_signal_to_deliver(),
tracehook_signal_handler() and signal_delivered().
At the end of the day we save around 500 lines of code."
* 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits)
powerpc: Use sigsp()
openrisc: Use sigsp()
mn10300: Use sigsp()
mips: Use sigsp()
microblaze: Use sigsp()
metag: Use sigsp()
m68k: Use sigsp()
m32r: Use sigsp()
hexagon: Use sigsp()
frv: Use sigsp()
cris: Use sigsp()
c6x: Use sigsp()
blackfin: Use sigsp()
avr32: Use sigsp()
arm64: Use sigsp()
arc: Use sigsp()
sas_ss_flags: Remove nested ternary if
Rip out get_signal_to_deliver()
Clean up signal_delivered()
tracehook_signal_handler: Remove sig, info, ka and regs
...
Pull ARC changes from Vineet Gupta:
"Mostly cleanup/refactoring in core intc, cache flush, IPI send..."
* tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
mm, arc: remove obsolete pagefault oom killer comment
ARC: help gcc elide icache helper for !SMP
ARC: move common ops for line/full cache into helpers
ARC: cache boot reporting updates
ARC: [intc] mask/unmask can be hidden again
ARC: [plat-arcfpga] No need for init_irq hack
ARC: [intc] don't mask all IRQ by default
ARC: prune extra header includes from smp.c
ARC: update some comments
ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)
Use the more generic functions get_signal() signal_setup_done()
for signal delivery.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
