User space cannot disable interrupts any longer so trace return to user space
unconditionally as IRQS_ON.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200308222609.314596327@linutronix.de

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/20200308222609.219366430@linutronix.de

Nothing cares about the -1 "mark as interrupt" in the errorcode of
exception entries. It's only used to fill the error code when a signal is
delivered, but this is already inconsistent vs. 64 bit as there all
exceptions which do not have an error code set it to 0. So if 32 bit
applications would care about this, then they would have noticed more than
a decade ago.

Just use 0 for all excpetions which do not have an errorcode consistently.

This does neither break /proc/$PID/syscall because this interface examines
the error code / syscall number which is on the stack and that is set to -1
(no syscall) in common_exception unconditionally for all exceptions. The
push in the entry stub is just there to fill the hardware error code slot
on the stack for consistency of the stack layout.

A transient observation of 0 is possible, but that's true for the other
exceptions which use 0 already as well and that interface is an unreliable
snapshot of dubious correctness anyway.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Link: https://lkml.kernel.org/r/87mu94m7ky.fsf@nanos.tec.linutronix.de

#BP is not longer using IST and using ist_enter() and ist_exit() makes it
harder to change ist_enter() and ist_exit()'s behavior.  Instead open-code
the very small amount of required logic.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220217.150607679@linutronix.de

int3 is not using the common_exception path for purely historical reasons,
but there is no reason to keep it the only exception which is different.

Make it use common_exception so the upcoming changes to autogenerate the
entry stubs do not have to special case int3.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220217.042369808@linutronix.de

Nothing is using it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.826870369@linutronix.de

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.720335354@linutronix.de

Add a comment which explains why this empty handler for a reserved vector
exists.
Requested-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.624165786@linutronix.de

That function returns immediately after conditionally reenabling interrupts which
is more than pointless and requires the ASM code to disable interrupts again.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20191023123117.871608831@linutronix.de
Link: https://lkml.kernel.org/r/20200225220216.518575042@linutronix.de

Remove the pointless difference between 32 and 64 bit to make further
unifications simpler.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.428188397@linutronix.de

do_machine_check() can be raised in almost any context including the most
fragile ones. Prevent kprobes and tracing.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200225220216.315548935@linutronix.de

All exception entry points must have ASM_CLAC right at the
beginning. The general_protection entry is missing one.

Fixes: e59d1b0a ("x86-32, smap: Add STAC/CLAC instructions to 32-bit kernel entry")
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NFrederic Weisbecker <frederic@kernel.org>
Reviewed-by: NAlexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: NAndy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200225220216.219537887@linutronix.de

The C-Sky platform code is not a clock provider, and just needs to call
of_clk_init().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

This is required for clone3 which passes the TLS value through a
struct rather than a register.

Cc: Amanieu d'Antras <amanieu@gmail.com>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Add the pci related code for csky arch to support basic pci virtual
function, such as qemu virt-pci-9pfs.
Signed-off-by: NMaJun <majun258@linux.alibaba.com>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Some bsp (eg: buildroot) has defconfig.fragment design to add more
configs into the defconfig in linux source code tree. For example,
we could put different cpu configs into different defconfig.fragments,
but they all use the same defconfig in Linux.
Signed-off-by: NMa Jun <majun258@linux.alibaba.com>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

We should give some necessary check for initrd just like other
architectures and it seems that setup_initrd() could be a common
code for all architectures.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

CONFIG_CLKSRC_OF is gone since commit bb0eb050
("clocksource/drivers: Rename CLKSRC_OF to TIMER_OF").  The platform
already selects TIMER_OF.

CONFIG_HAVE_DMA_API_DEBUG is gone since commit 6e88628d ("dma-debug:
remove CONFIG_HAVE_DMA_API_DEBUG").

CONFIG_DEFAULT_DEADLINE is gone since commit f382fb0b ("block:
remove legacy IO schedulers").
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Fix wording in help text for the CPU_HAS_LDSTEX symbol.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NGuo Ren <guoren@kernel.org>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Implement fstat64, fstatat64, clone3 syscalls to fixup
checksyscalls.sh compile warnings.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Only for coding convention, these codes are unnecessary for abiv2.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

During ftrace init, linux will replace all function prologues
(call_mcout) with nops, but it need flush_dcache and
invalidate_icache to make it work. So flush_cache functions
couldn't be nested called by ftrace framework.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Some CPUs don't support icache.va instruction to maintain the whole
smp cores' icache. Using icache.all + IPI casue a lot on performace
and using defer mechanism could reduce the number of calling icache
_flush_all functions.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Only when vma is for VM_EXEC, we need sync dcache & icache. eg:
 - gdb ptrace modify user space instruction code area.

Add VM_EXEC condition to reduce unnecessary cache flush.

The abiv1 cpus' cache are all VIPT, so we still need to deal with
dcache aliasing problem. But there is optimized way to use cache
color, just like what's done in arch/csky/abiv1/inc/abi/page.h.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Instead of flushing cache per update_mmu_cache() called, we use
flush_dcache_page to reduce the frequency of flashing the cache.

As abiv2 cpus are all PIPT for icache & dcache, we needn't handle
dcache aliasing problem. But their icache can't snoop dcache, so
we still need sync_icache_dcache in update_mmu_cache().
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

The abiv2 CPUs are all PIPT cache, so there is no need to implement
flush_icache_page function.

The function flush_icache_user_range hasn't been used, so just
remove it.

The function flush_cache_range is not necessary for PIPT cache when
tlb mapping changed.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Some CPUs don't support icache specific instructions to flush icache
lines in broadcast way. We use cpu control registers to flush local
icache and use IPI to notify other cores.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Such as snps,dw-apb-ictl
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

If we use a non-ipi-support interrupt controller, it will cause panic here.
We should let cpu up and work with CONFIG_SMP, when we use a non-ipi intc.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

In the past, we didn't care about kernel sp when saving pt_reg. But in some
cases, we still need pt_reg->usp to represent the kernel stack before enter
exception.

For cmpxhg in atomic.S, we need save and restore usp for above.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

There is no present bit in csky pmd hardware, so we need to prepare invalid_pte_table
for empty pmd entry and the functions (pmd_none & pmd_present) in pgtable.h need
invalid_pte_talbe to get result. If a module use these functions, we need export the
symbol for it.
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>
Cc: Mo Qihui <qihui.mo@verisilicon.com>
Cc: Zhange Jian <zhang_jian5@dahuatech.com>

After fixaddr_init is separated from highmem, we could use tcm
without highmem selected. (610 (abiv1) don't support highmem,
but it could use tcm now.)
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

The implementation are not only used by TCM but also used by sram on
SOC bus. It follow existed linux tcm software interface, so that old
tcm application codes could be re-used directly.

Software interface list in asm/tcm.h:
 - Variables/Const: 	__tcmdata, __tcmconst
 - Functions:		__tcmfunc, __tcmlocalfunc
 - Malloc/Free:		tcm_alloc, tcm_free

In linux menuconfig:
 - Choose a TCM contain instrctions + data or separated in ITCM/DTCM.
 - Determine TCM_BASE (DTCM_BASE) in phyiscal address.
 - Determine size of TCM or ITCM(DTCM) in page counts.

Here is hello tcm example from Documentation/arm/tcm.rst which could
be directly used:

/* Uninitialized data */
static u32 __tcmdata tcmvar;
/* Initialized data */
static u32 __tcmdata tcmassigned = 0x2BADBABEU;
/* Constant */
static const u32 __tcmconst tcmconst = 0xCAFEBABEU;

static void __tcmlocalfunc tcm_to_tcm(void)
{
	int i;
	for (i = 0; i < 100; i++)
		tcmvar ++;
}

static void __tcmfunc hello_tcm(void)
{
	/* Some abstract code that runs in ITCM */
	int i;
	for (i = 0; i < 100; i++) {
		tcmvar ++;
	}
	tcm_to_tcm();
}

static void __init test_tcm(void)
{
	u32 *tcmem;
	int i;

	hello_tcm();
	printk("Hello TCM executed from ITCM RAM\n");

	printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar);
	tcmvar = 0xDEADBEEFU;
	printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar);

	printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned);

	printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst);

	/* Allocate some TCM memory from the pool */
	tcmem = tcm_alloc(20);
	if (tcmem) {
		printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem);
		tcmem[0] = 0xDEADBEEFU;
		tcmem[1] = 0x2BADBABEU;
		tcmem[2] = 0xCAFEBABEU;
		tcmem[3] = 0xDEADBEEFU;
		tcmem[4] = 0x2BADBABEU;
		for (i = 0; i < 5; i++)
			printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]);
		tcm_free(tcmem, 20);
	}
}

TODO:
 - Separate fixup mapping from highmem
 - Support abiv1
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

This is a basic -fstack-protector support without per-task canary
switching. The protector will report something like when stack
corruption is detected:

It's tested with strcpy local array overflow in sys_kill and get:
stack-protector: Kernel stack is corrupted in: sys_kill+0x23c/0x23c

TODO:
 - Support task switch for different cannary
Signed-off-by: NMao Han <han_mao@c-sky.com>
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>

Variables declared in a switch statement before any case statements
cannot be automatically initialized with compiler instrumentation (as
they are not part of any execution flow). With GCC's proposed automatic
stack variable initialization feature, this triggers a warning (and they
don't get initialized). Clang's automatic stack variable initialization
(via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also
doesn't initialize such variables[1]. Note that these warnings (or silent
skipping) happen before the dead-store elimination optimization phase,
so even when the automatic initializations are later elided in favor of
direct initializations, the warnings remain.

To avoid these problems, move such variables into the "case" where
they're used or lift them up into the main function body.

arch/x86/xen/enlighten_pv.c: In function ‘xen_write_msr_safe’:
arch/x86/xen/enlighten_pv.c:904:12: warning: statement will never be executed [-Wswitch-unreachable]
  904 |   unsigned which;
      |            ^~~~~

[1] https://bugs.llvm.org/show_bug.cgi?id=44916Signed-off-by: NKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200220062318.69299-1-keescook@chromium.orgReviewed-by: NJuergen Gross <jgross@suse.com>
[boris: made @which an 'unsigned int']
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>

Commit

  aaf24884 ("perf/x86/msr: Add AMD IRPERF (Instructions Retired)
		  performance counter")

added support for access to the free-running counter via 'perf -e
msr/irperf/', but when exercised, it always returns a 0 count:

BEFORE:

  $ perf stat -e instructions,msr/irperf/ true

   Performance counter stats for 'true':

             624,833      instructions
                   0      msr/irperf/

Simply set its enable bit - HWCR bit 30 - to make it start counting.

Enablement is restricted to all machines advertising IRPERF capability,
except those susceptible to an erratum that makes the IRPERF return
bad values.

That erratum occurs in Family 17h models 00-1fh [1], but not in F17h
models 20h and above [2].

AFTER (on a family 17h model 31h machine):

  $ perf stat -e instructions,msr/irperf/ true

   Performance counter stats for 'true':

             621,690      instructions
             622,490      msr/irperf/

[1] Revision Guide for AMD Family 17h Models 00h-0Fh Processors
[2] Revision Guide for AMD Family 17h Models 30h-3Fh Processors

The revision guides are available from the bugzilla Link below.

 [ bp: Massage commit message. ]

Fixes: aaf24884 ("perf/x86/msr: Add AMD IRPERF (Instructions Retired) performance counter")
Signed-off-by: NKim Phillips <kim.phillips@amd.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
Link: http://lkml.kernel.org/r/20200214201805.13830-1-kim.phillips@amd.com

sbale->addr holds an absolute address (or for some FCP usage, an opaque
request ID), and should only be used with proper virt/phys translation.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NBenjamin Block <bblock@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

As the comment says, sl->sbal holds an absolute address. qeth currently
solves this through wild casting, while zfcp doesn't care.

Handle this properly in the code that actually builds the SL.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com> [for qdio]
Reviewed-by: NBenjamin Block <bblock@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

GCC 10 changed the default to -fno-common, which leads to

    LD      arch/x86/boot/compressed/vmlinux
  ld: arch/x86/boot/compressed/pgtable_64.o:(.bss+0x0): multiple definition of `__force_order'; \
    arch/x86/boot/compressed/kaslr_64.o:(.bss+0x0): first defined here
  make[2]: *** [arch/x86/boot/compressed/Makefile:119: arch/x86/boot/compressed/vmlinux] Error 1

Since __force_order is already provided in pgtable_64.c, there is no
need to declare __force_order in kaslr_64.c.
Signed-off-by: NH.J. Lu <hjl.tools@gmail.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200124181811.4780-1-hjl.tools@gmail.com

Add brackets around the evaluation of the 'addr' parameter to the
untagged_addr() macro so that the cast to 'u64' applies to the result
of the expression.

Cc: <stable@vger.kernel.org>
Fixes: 597399d0 ("arm64: tags: Preserve tags for addresses translated via TTBR1")
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NWill Deacon <will@kernel.org>