linux.git/arch/x86/kernel/setup_percpu.c, branch v6.0

mm: percpu: add generic pcpu_populate_pte() function

2022-01-20T06:52:52+00:00

With NEED_PER_CPU_PAGE_FIRST_CHUNK enabled, we need a function to
populate pte, this patch adds a generic pcpu populate pte function,
pcpu_populate_pte(), which is marked __weak and used on most
architectures, but it is overridden on x86, which has its own
implementation.

Link: https://lkml.kernel.org/r/20211216112359.103822-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: "H. Peter Anvin" 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Albert Ou 
Cc: Catalin Marinas 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Thomas Bogendoerfer 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: percpu: add generic pcpu_fc_alloc/free funciton

2022-01-20T06:52:52+00:00

With the previous patch, we could add a generic pcpu first chunk
allocate and free function to cleanup the duplicated definations on each
architecture.

Link: https://lkml.kernel.org/r/20211216112359.103822-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Thomas Bogendoerfer 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: "H. Peter Anvin" 
Cc: Greg Kroah-Hartman 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Albert Ou 
Cc: Catalin Marinas 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: "Rafael J. Wysocki" 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: percpu: add pcpu_fc_cpu_to_node_fn_t typedef

2022-01-20T06:52:52+00:00

Add pcpu_fc_cpu_to_node_fn_t and pass it into pcpu_fc_alloc_fn_t, pcpu
first chunk allocation will call it to alloc memblock on the
corresponding node by it, this is prepare for the next patch.

Link: https://lkml.kernel.org/r/20211216112359.103822-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Thomas Bogendoerfer 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: "H. Peter Anvin" 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Albert Ou 
Cc: Catalin Marinas 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: use memblock_free for freeing virtual pointers

2021-11-06T20:30:41+00:00

Rename memblock_free_ptr() to memblock_free() and use memblock_free()
when freeing a virtual pointer so that memblock_free() will be a
counterpart of memblock_alloc()

The callers are updated with the below semantic patch and manual
addition of (void *) casting to pointers that are represented by
unsigned long variables.

    @@
    identifier vaddr;
    expression size;
    @@
    (
    - memblock_phys_free(__pa(vaddr), size);
    + memblock_free(vaddr, size);
    |
    - memblock_free_ptr(vaddr, size);
    + memblock_free(vaddr, size);
    )

[sfr@canb.auug.org.au: fixup]
  Link: https://lkml.kernel.org/r/20211018192940.3d1d532f@canb.auug.org.au

Link: https://lkml.kernel.org/r/20210930185031.18648-7-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Signed-off-by: Stephen Rothwell 
Cc: Christophe Leroy 
Cc: Juergen Gross 
Cc: Shahab Vahedi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: introduce saner 'memblock_free_ptr()' interface

2021-09-14T20:23:22+00:00

The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.

Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:

   https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/

or just random memory corruption if the debug checks don't catch it:

   https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/

I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.

I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.

So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer.  And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.

Reported-by: kernel test robot 
Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Cc: Steven Rostedt 
Cc: Mike Rapoport 
Cc: Andrew Morton 
Cc: Ingo Molnar 
Cc: Masami Hiramatsu 
Cc: Vlastimil Babka 
Signed-off-by: Linus Torvalds

mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA

2021-06-29T17:53:55+00:00

After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
configuration options are equivalent.

Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.

Done with

	$ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
		$(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
	$ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
		$(git grep -wl NEED_MULTIPLE_NODES)

with manual tweaks afterwards.

[rppt@linux.ibm.com: fix arm boot crash]
  Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com

Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Acked-by: Arnd Bergmann 
Acked-by: David Hildenbrand 
Cc: Geert Uytterhoeven 
Cc: Ivan Kokshaysky 
Cc: Jonathan Corbet 
Cc: Matt Turner 
Cc: Richard Henderson 
Cc: Vineet Gupta 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

x86/stackprotector/32: Make the canary into a regular percpu variable

2021-03-08T12:19:05+00:00

On 32-bit kernels, the stackprotector canary is quite nasty -- it is
stored at %gs:(20), which is nasty because 32-bit kernels use %fs for
percpu storage. It's even nastier because it means that whether %gs
contains userspace state or kernel state while running kernel code
depends on whether stackprotector is enabled (this is
CONFIG_X86_32_LAZY_GS), and this setting radically changes the way
that segment selectors work. Supporting both variants is a
maintenance and testing mess.

Merely rearranging so that percpu and the stack canary
share the same segment would be messy as the 32-bit percpu address
layout isn't currently compatible with putting a variable at a fixed
offset.

Fortunately, GCC 8.1 added options that allow the stack canary to be
accessed as %fs:__stack_chk_guard, effectively turning it into an ordinary
percpu variable. This lets us get rid of all of the code to manage the
stack canary GDT descriptor and the CONFIG_X86_32_LAZY_GS mess.

(That name is special. We could use any symbol we want for the
%fs-relative mode, but for CONFIG_SMP=n, gcc refuses to let us use any
name other than __stack_chk_guard.)

Forcibly disable stackprotector on older compilers that don't support
the new options and turn the stack canary into a percpu variable. The
"lazy GS" approach is now used for all 32-bit configurations.

Also makes load_gs_index() work on 32-bit kernels. On 64-bit kernels,
it loads the GS selector and updates the user GSBASE accordingly. (This
is unchanged.) On 32-bit kernels, it loads the GS selector and updates
GSBASE, which is now always the user base. This means that the overall
effect is the same on 32-bit and 64-bit, which avoids some ifdeffery.

[ bp: Massage commit message. ]

Signed-off-by: Andy Lutomirski
Signed-off-by: Borislav Petkov
Link: https://lkml.kernel.org/r/c0ff7dba14041c7e5d1cae5d4df052f03759bef3.1613243844.git.luto@kernel.org

x86/mm: remove vmalloc faulting

2020-06-02T17:59:12+00:00

Remove fault handling on vmalloc areas, as the vmalloc code now takes
care of synchronizing changes to all page-tables in the system.

Signed-off-by: Joerg Roedel 
Signed-off-by: Andrew Morton 
Acked-by: Andy Lutomirski 
Acked-by: Peter Zijlstra (Intel) 
Cc: Arnd Bergmann 
Cc: Christoph Hellwig 
Cc: Dave Hansen 
Cc: "H . Peter Anvin" 
Cc: Ingo Molnar 
Cc: Matthew Wilcox (Oracle) 
Cc: Michal Hocko 
Cc: "Rafael J. Wysocki" 
Cc: Steven Rostedt (VMware) 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Link: http://lkml.kernel.org/r/20200515140023.25469-8-joro@8bytes.org
Signed-off-by: Linus Torvalds

x86: Use pr_warn instead of pr_warning

2019-10-18T13:00:18+00:00

As said in commit f2c2cbcc35d4 ("powerpc: Use pr_warn instead of
pr_warning"), removing pr_warning so all logging messages use a
consistent _warn style. Let's do it.

Link: http://lkml.kernel.org/r/20191018031850.48498-7-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Robert Richter 
Cc: Darren Hart 
Cc: Andy Shevchenko 
Signed-off-by: Kefeng Wang 
Reviewed-by: Sergey Senozhatsky 
Signed-off-by: Petr Mladek

x86/irq/64: Split the IRQ stack into its own pages

2019-04-17T13:37:02+00:00

Currently, the IRQ stack is hardcoded as the first page of the percpu
area, and the stack canary lives on the IRQ stack. The former gets in
the way of adding an IRQ stack guard page, and the latter is a potential
weakness in the stack canary mechanism.

Split the IRQ stack into its own private percpu pages.

[ tglx: Make 64 and 32 bit share struct irq_stack ]

Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Cc: Alexey Dobriyan 
Cc: Andrew Morton 
Cc: Ard Biesheuvel 
Cc: Boris Ostrovsky 
Cc: Brijesh Singh 
Cc: "Chang S. Bae" 
Cc: Dominik Brodowski 
Cc: Feng Tang 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jan Beulich 
Cc: Jiri Kosina 
Cc: Joerg Roedel 
Cc: Jordan Borgner 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Konrad Rzeszutek Wilk 
Cc: Maran Wilson 
Cc: Masahiro Yamada 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Nick Desaulniers 
Cc: Nicolai Stange 
Cc: Peter Zijlstra 
Cc: Pu Wen 
Cc: "Rafael Ávila de Espíndola" 
Cc: Sean Christopherson 
Cc: Stefano Stabellini 
Cc: Vlastimil Babka 
Cc: x86-ml 
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20190414160146.267376656@linutronix.de