<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/arm64/kernel/module.c, branch v6.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge branch 'for-next/ftrace' into for-next/core</title>
<updated>2022-12-06T11:07:39+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will@kernel.org</email>
</author>
<published>2022-12-06T11:07:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a4aebff7ef608880149851e0679e3ab455c0d42f'/>
<id>a4aebff7ef608880149851e0679e3ab455c0d42f</id>
<content type='text'>
* for-next/ftrace:
  ftrace: arm64: remove static ftrace
  ftrace: arm64: move from REGS to ARGS
  ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses
  ftrace: rename ftrace_instruction_pointer_set() -&gt; ftrace_regs_set_instruction_pointer()
  ftrace: pass fregs to arch_ftrace_set_direct_caller()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* for-next/ftrace:
  ftrace: arm64: remove static ftrace
  ftrace: arm64: move from REGS to ARGS
  ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses
  ftrace: rename ftrace_instruction_pointer_set() -&gt; ftrace_regs_set_instruction_pointer()
  ftrace: pass fregs to arch_ftrace_set_direct_caller()
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: arm64: move from REGS to ARGS</title>
<updated>2022-11-18T13:56:41+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2022-11-03T17:05:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=26299b3f6ba26bfc234b73126d14bdf4dec5275a'/>
<id>26299b3f6ba26bfc234b73126d14bdf4dec5275a</id>
<content type='text'>
This commit replaces arm64's support for FTRACE_WITH_REGS with support
for FTRACE_WITH_ARGS. This removes some overhead and complexity, and
removes some latent issues with inconsistent presentation of struct
pt_regs (which can only be reliably saved/restored at exception
boundaries).

FTRACE_WITH_REGS has been supported on arm64 since commit:

  3b23e4991fb66f6d ("arm64: implement ftrace with regs")

As noted in the commit message, the major reasons for implementing
FTRACE_WITH_REGS were:

(1) To make it possible to use the ftrace graph tracer with pointer
    authentication, where it's necessary to snapshot/manipulate the LR
    before it is signed by the instrumented function.

(2) To make it possible to implement LIVEPATCH in future, where we need
    to hook function entry before an instrumented function manipulates
    the stack or argument registers. Practically speaking, we need to
    preserve the argument/return registers, PC, LR, and SP.

Neither of these need a struct pt_regs, and only require the set of
registers which are live at function call/return boundaries. Our calling
convention is defined by "Procedure Call Standard for the Arm® 64-bit
Architecture (AArch64)" (AKA "AAPCS64"), which can currently be found
at:

  https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst

Per AAPCS64, all function call argument and return values are held in
the following GPRs:

* X0 - X7 : parameter / result registers
* X8      : indirect result location register
* SP      : stack pointer (AKA SP)

Additionally, ad function call boundaries, the following GPRs hold
context/return information:

* X29 : frame pointer (AKA FP)
* X30 : link register (AKA LR)

... and for ftrace we need to capture the instrumented address:

 * PC  : program counter

No other GPRs are relevant, as none of the other arguments hold
parameters or return values:

* X9  - X17 : temporaries, may be clobbered
* X18       : shadow call stack pointer (or temorary)
* X19 - X28 : callee saved

This patch implements FTRACE_WITH_ARGS for arm64, only saving/restoring
the minimal set of registers necessary. This is always sufficient to
manipulate control flow (e.g. for live-patching) or to manipulate
function arguments and return values.

This reduces the necessary stack usage from 336 bytes for pt_regs down
to 112 bytes for ftrace_regs + 32 bytes for two frame records, freeing
up 188 bytes. This could be reduced further with changes to the
unwinder.

As there is no longer a need to save different sets of registers for
different features, we no longer need distinct `ftrace_caller` and
`ftrace_regs_caller` trampolines. This allows the trampoline assembly to
be simpler, and simplifies code which previously had to handle the two
trampolines.

I've tested this with the ftrace selftests, where there are no
unexpected failures.

Co-developed-by: Florent Revest &lt;revest@chromium.org&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Florent Revest &lt;revest@chromium.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Reviewed-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/20221103170520.931305-5-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This commit replaces arm64's support for FTRACE_WITH_REGS with support
for FTRACE_WITH_ARGS. This removes some overhead and complexity, and
removes some latent issues with inconsistent presentation of struct
pt_regs (which can only be reliably saved/restored at exception
boundaries).

FTRACE_WITH_REGS has been supported on arm64 since commit:

  3b23e4991fb66f6d ("arm64: implement ftrace with regs")

As noted in the commit message, the major reasons for implementing
FTRACE_WITH_REGS were:

(1) To make it possible to use the ftrace graph tracer with pointer
    authentication, where it's necessary to snapshot/manipulate the LR
    before it is signed by the instrumented function.

(2) To make it possible to implement LIVEPATCH in future, where we need
    to hook function entry before an instrumented function manipulates
    the stack or argument registers. Practically speaking, we need to
    preserve the argument/return registers, PC, LR, and SP.

Neither of these need a struct pt_regs, and only require the set of
registers which are live at function call/return boundaries. Our calling
convention is defined by "Procedure Call Standard for the Arm® 64-bit
Architecture (AArch64)" (AKA "AAPCS64"), which can currently be found
at:

  https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst

Per AAPCS64, all function call argument and return values are held in
the following GPRs:

* X0 - X7 : parameter / result registers
* X8      : indirect result location register
* SP      : stack pointer (AKA SP)

Additionally, ad function call boundaries, the following GPRs hold
context/return information:

* X29 : frame pointer (AKA FP)
* X30 : link register (AKA LR)

... and for ftrace we need to capture the instrumented address:

 * PC  : program counter

No other GPRs are relevant, as none of the other arguments hold
parameters or return values:

* X9  - X17 : temporaries, may be clobbered
* X18       : shadow call stack pointer (or temorary)
* X19 - X28 : callee saved

This patch implements FTRACE_WITH_ARGS for arm64, only saving/restoring
the minimal set of registers necessary. This is always sufficient to
manipulate control flow (e.g. for live-patching) or to manipulate
function arguments and return values.

This reduces the necessary stack usage from 336 bytes for pt_regs down
to 112 bytes for ftrace_regs + 32 bytes for two frame records, freeing
up 188 bytes. This could be reduced further with changes to the
unwinder.

As there is no longer a need to save different sets of registers for
different features, we no longer need distinct `ftrace_caller` and
`ftrace_regs_caller` trampolines. This allows the trampoline assembly to
be simpler, and simplifies code which previously had to handle the two
trampolines.

I've tested this with the ftrace selftests, where there are no
unexpected failures.

Co-developed-by: Florent Revest &lt;revest@chromium.org&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Florent Revest &lt;revest@chromium.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: Masami Hiramatsu (Google) &lt;mhiramat@kernel.org&gt;
Reviewed-by: Steven Rostedt (Google) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/20221103170520.931305-5-mark.rutland@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: implement dynamic shadow call stack for Clang</title>
<updated>2022-11-09T18:06:35+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2022-10-27T15:59:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3b619e22c4601b444ed2d6a5458271f72625ac89'/>
<id>3b619e22c4601b444ed2d6a5458271f72625ac89</id>
<content type='text'>
Implement dynamic shadow call stack support on Clang, by parsing the
unwind tables at init time to locate all occurrences of PACIASP/AUTIASP
instructions, and replacing them with the shadow call stack push and pop
instructions, respectively.

This is useful because the overhead of the shadow call stack is
difficult to justify on hardware that implements pointer authentication
(PAC), and given that the PAC instructions are executed as NOPs on
hardware that doesn't, we can just replace them without breaking
anything. As PACIASP/AUTIASP are guaranteed to be paired with respect to
manipulations of the return address, replacing them 1:1 with shadow call
stack pushes and pops is guaranteed to result in the desired behavior.

Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Reviewed-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Tested-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Link: https://lore.kernel.org/r/20221027155908.1940624-4-ardb@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Implement dynamic shadow call stack support on Clang, by parsing the
unwind tables at init time to locate all occurrences of PACIASP/AUTIASP
instructions, and replacing them with the shadow call stack push and pop
instructions, respectively.

This is useful because the overhead of the shadow call stack is
difficult to justify on hardware that implements pointer authentication
(PAC), and given that the PAC instructions are executed as NOPs on
hardware that doesn't, we can just replace them without breaking
anything. As PACIASP/AUTIASP are guaranteed to be paired with respect to
manipulations of the return address, replacing them 1:1 with shadow call
stack pushes and pops is guaranteed to result in the desired behavior.

Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Reviewed-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Tested-by: Sami Tolvanen &lt;samitolvanen@google.com&gt;
Link: https://lore.kernel.org/r/20221027155908.1940624-4-ardb@kernel.org
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: module: move find_section to header</title>
<updated>2022-09-09T11:27:25+00:00</updated>
<author>
<name>Joey Gouly</name>
<email>joey.gouly@arm.com</email>
</author>
<published>2022-08-30T10:48:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3adc3844e1dedd05fa8d09633eaa8ddc5ddcece'/>
<id>b3adc3844e1dedd05fa8d09633eaa8ddc5ddcece</id>
<content type='text'>
Move it to the header so that the implementation can be shared
by the alternatives code.

Signed-off-by: Joey Gouly &lt;joey.gouly@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Link: https://lore.kernel.org/r/20220830104833.34636-2-joey.gouly@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move it to the header so that the implementation can be shared
by the alternatives code.

Signed-off-by: Joey Gouly &lt;joey.gouly@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Acked-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Link: https://lore.kernel.org/r/20220830104833.34636-2-joey.gouly@arm.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kasan, arm64: don't tag executable vmalloc allocations</title>
<updated>2022-03-25T02:06:48+00:00</updated>
<author>
<name>Andrey Konovalov</name>
<email>andreyknvl@google.com</email>
</author>
<published>2022-03-25T01:11:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=36c4a73bf8d24721222d9ee4080ac955973fd388'/>
<id>36c4a73bf8d24721222d9ee4080ac955973fd388</id>
<content type='text'>
Besides asking vmalloc memory to be executable via the prot argument of
__vmalloc_node_range() (see the previous patch), the kernel can skip that
bit and instead mark memory as executable via set_memory_x().

Once tag-based KASAN modes start tagging vmalloc allocations, executing
code from such allocations will lead to the PC register getting a tag,
which is not tolerated by the kernel.

Generic kernel code typically allocates memory via module_alloc() if it
intends to mark memory as executable.  (On arm64 module_alloc() uses
__vmalloc_node_range() without setting the executable bit).

Thus, reset pointer tags of pointers returned from module_alloc().

However, on arm64 there's an exception: the eBPF subsystem.  Instead of
using module_alloc(), it uses vmalloc() (via bpf_jit_alloc_exec()) to
allocate its JIT region.

Thus, reset pointer tags of pointers returned from bpf_jit_alloc_exec().

Resetting tags for these pointers results in untagged pointers being
passed to set_memory_x().  This causes conflicts in arithmetic checks in
change_memory_common(), as vm_struct-&gt;addr pointer returned by
find_vm_area() is tagged.

Reset pointer tag of find_vm_area(addr)-&gt;addr in change_memory_common().

Link: https://lkml.kernel.org/r/b7b2595423340cd7d76b770e5d519acf3b72f0ab.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Collingbourne &lt;pcc@google.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Besides asking vmalloc memory to be executable via the prot argument of
__vmalloc_node_range() (see the previous patch), the kernel can skip that
bit and instead mark memory as executable via set_memory_x().

Once tag-based KASAN modes start tagging vmalloc allocations, executing
code from such allocations will lead to the PC register getting a tag,
which is not tolerated by the kernel.

Generic kernel code typically allocates memory via module_alloc() if it
intends to mark memory as executable.  (On arm64 module_alloc() uses
__vmalloc_node_range() without setting the executable bit).

Thus, reset pointer tags of pointers returned from module_alloc().

However, on arm64 there's an exception: the eBPF subsystem.  Instead of
using module_alloc(), it uses vmalloc() (via bpf_jit_alloc_exec()) to
allocate its JIT region.

Thus, reset pointer tags of pointers returned from bpf_jit_alloc_exec().

Resetting tags for these pointers results in untagged pointers being
passed to set_memory_x().  This causes conflicts in arithmetic checks in
change_memory_common(), as vm_struct-&gt;addr pointer returned by
find_vm_area() is tagged.

Reset pointer tag of find_vm_area(addr)-&gt;addr in change_memory_common().

Link: https://lkml.kernel.org/r/b7b2595423340cd7d76b770e5d519acf3b72f0ab.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Collingbourne &lt;pcc@google.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kasan, x86, arm64, s390: rename functions for modules shadow</title>
<updated>2022-03-25T02:06:47+00:00</updated>
<author>
<name>Andrey Konovalov</name>
<email>andreyknvl@google.com</email>
</author>
<published>2022-03-25T01:10:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=63840de296472f3914bb933b11ba2b764590755e'/>
<id>63840de296472f3914bb933b11ba2b764590755e</id>
<content type='text'>
Rename kasan_free_shadow to kasan_free_module_shadow and
kasan_module_alloc to kasan_alloc_module_shadow.

These functions are used to allocate/free shadow memory for kernel modules
when KASAN_VMALLOC is not enabled.  The new names better reflect their
purpose.

Also reword the comment next to their declaration to improve clarity.

Link: https://lkml.kernel.org/r/36db32bde765d5d0b856f77d2d806e838513fe84.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Collingbourne &lt;pcc@google.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rename kasan_free_shadow to kasan_free_module_shadow and
kasan_module_alloc to kasan_alloc_module_shadow.

These functions are used to allocate/free shadow memory for kernel modules
when KASAN_VMALLOC is not enabled.  The new names better reflect their
purpose.

Also reword the comment next to their declaration to improve clarity.

Link: https://lkml.kernel.org/r/36db32bde765d5d0b856f77d2d806e838513fe84.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Marco Elver &lt;elver@google.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Collingbourne &lt;pcc@google.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: defer kmemleak object creation of module_alloc()</title>
<updated>2022-01-15T14:30:25+00:00</updated>
<author>
<name>Kefeng Wang</name>
<email>wangkefeng.wang@huawei.com</email>
</author>
<published>2022-01-14T22:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=60115fa54ad7b913b7cb5844e6b7ffeb842d55f2'/>
<id>60115fa54ad7b913b7cb5844e6b7ffeb842d55f2</id>
<content type='text'>
Yongqiang reports a kmemleak panic when module insmod/rmmod with KASAN
enabled(without KASAN_VMALLOC) on x86[1].

When the module area allocates memory, it's kmemleak_object is created
successfully, but the KASAN shadow memory of module allocation is not
ready, so when kmemleak scan the module's pointer, it will panic due to
no shadow memory with KASAN check.

  module_alloc
    __vmalloc_node_range
      kmemleak_vmalloc
				kmemleak_scan
				  update_checksum
    kasan_module_alloc
      kmemleak_ignore

Note, there is no problem if KASAN_VMALLOC enabled, the modules area
entire shadow memory is preallocated.  Thus, the bug only exits on ARCH
which supports dynamic allocation of module area per module load, for
now, only x86/arm64/s390 are involved.

Add a VM_DEFER_KMEMLEAK flags, defer vmalloc'ed object register of
kmemleak in module_alloc() to fix this issue.

[1] https://lore.kernel.org/all/6d41e2b9-4692-5ec4-b1cd-cbe29ae89739@huawei.com/

[wangkefeng.wang@huawei.com: fix build]
  Link: https://lkml.kernel.org/r/20211125080307.27225-1-wangkefeng.wang@huawei.com
[akpm@linux-foundation.org: simplify ifdefs, per Andrey]
  Link: https://lkml.kernel.org/r/CA+fCnZcnwJHUQq34VuRxpdoY6_XbJCDJ-jopksS5Eia4PijPzw@mail.gmail.com

Link: https://lkml.kernel.org/r/20211124142034.192078-1-wangkefeng.wang@huawei.com
Fixes: 793213a82de4 ("s390/kasan: dynamic shadow mem allocation for modules")
Fixes: 39d114ddc682 ("arm64: add KASAN support")
Fixes: bebf56a1b176 ("kasan: enable instrumentation of global variables")
Signed-off-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Reported-by: Yongqiang Liu &lt;liuyongqiang13@huawei.com&gt;
Cc: Andrey Konovalov &lt;andreyknvl@gmail.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Yongqiang reports a kmemleak panic when module insmod/rmmod with KASAN
enabled(without KASAN_VMALLOC) on x86[1].

When the module area allocates memory, it's kmemleak_object is created
successfully, but the KASAN shadow memory of module allocation is not
ready, so when kmemleak scan the module's pointer, it will panic due to
no shadow memory with KASAN check.

  module_alloc
    __vmalloc_node_range
      kmemleak_vmalloc
				kmemleak_scan
				  update_checksum
    kasan_module_alloc
      kmemleak_ignore

Note, there is no problem if KASAN_VMALLOC enabled, the modules area
entire shadow memory is preallocated.  Thus, the bug only exits on ARCH
which supports dynamic allocation of module area per module load, for
now, only x86/arm64/s390 are involved.

Add a VM_DEFER_KMEMLEAK flags, defer vmalloc'ed object register of
kmemleak in module_alloc() to fix this issue.

[1] https://lore.kernel.org/all/6d41e2b9-4692-5ec4-b1cd-cbe29ae89739@huawei.com/

[wangkefeng.wang@huawei.com: fix build]
  Link: https://lkml.kernel.org/r/20211125080307.27225-1-wangkefeng.wang@huawei.com
[akpm@linux-foundation.org: simplify ifdefs, per Andrey]
  Link: https://lkml.kernel.org/r/CA+fCnZcnwJHUQq34VuRxpdoY6_XbJCDJ-jopksS5Eia4PijPzw@mail.gmail.com

Link: https://lkml.kernel.org/r/20211124142034.192078-1-wangkefeng.wang@huawei.com
Fixes: 793213a82de4 ("s390/kasan: dynamic shadow mem allocation for modules")
Fixes: 39d114ddc682 ("arm64: add KASAN support")
Fixes: bebf56a1b176 ("kasan: enable instrumentation of global variables")
Signed-off-by: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Reported-by: Yongqiang Liu &lt;liuyongqiang13@huawei.com&gt;
Cc: Andrey Konovalov &lt;andreyknvl@gmail.com&gt;
Cc: Andrey Ryabinin &lt;ryabinin.a.a@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Christian Borntraeger &lt;borntraeger@linux.ibm.com&gt;
Cc: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Alexander Potapenko &lt;glider@google.com&gt;
Cc: Kefeng Wang &lt;wangkefeng.wang@huawei.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: kaslr: support randomized module area with KASAN_VMALLOC</title>
<updated>2021-03-29T11:35:05+00:00</updated>
<author>
<name>Lecopzer Chen</name>
<email>lecopzer.chen@mediatek.com</email>
</author>
<published>2021-03-24T04:05:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=31d02e7ab00873befd2cfb6e44581490d947c38b'/>
<id>31d02e7ab00873befd2cfb6e44581490d947c38b</id>
<content type='text'>
After KASAN_VMALLOC works in arm64, we can randomize module region
into vmalloc area now.

Test:
	VMALLOC area ffffffc010000000 fffffffdf0000000

	before the patch:
		module_alloc_base/end ffffffc008b80000 ffffffc010000000
	after the patch:
		module_alloc_base/end ffffffdcf4bed000 ffffffc010000000

	And the function that insmod some modules is fine.

Suggested-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Lecopzer Chen &lt;lecopzer.chen@mediatek.com&gt;
Link: https://lore.kernel.org/r/20210324040522.15548-5-lecopzer.chen@mediatek.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After KASAN_VMALLOC works in arm64, we can randomize module region
into vmalloc area now.

Test:
	VMALLOC area ffffffc010000000 fffffffdf0000000

	before the patch:
		module_alloc_base/end ffffffc008b80000 ffffffc010000000
	after the patch:
		module_alloc_base/end ffffffdcf4bed000 ffffffc010000000

	And the function that insmod some modules is fine.

Suggested-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Signed-off-by: Lecopzer Chen &lt;lecopzer.chen@mediatek.com&gt;
Link: https://lore.kernel.org/r/20210324040522.15548-5-lecopzer.chen@mediatek.com
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kasan, arm64: expand CONFIG_KASAN checks</title>
<updated>2020-12-22T20:55:08+00:00</updated>
<author>
<name>Andrey Konovalov</name>
<email>andreyknvl@google.com</email>
</author>
<published>2020-12-22T20:02:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0fea6e9af889f1a4e072f5de999e07fe6859fc88'/>
<id>0fea6e9af889f1a4e072f5de999e07fe6859fc88</id>
<content type='text'>
Some #ifdef CONFIG_KASAN checks are only relevant for software KASAN modes
(either related to shadow memory or compiler instrumentation).  Expand
those into CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS.

Link: https://lkml.kernel.org/r/e6971e432dbd72bb897ff14134ebb7e169bdcf0c.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Signed-off-by: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reviewed-by: Alexander Potapenko &lt;glider@google.com&gt;
Tested-by: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Branislav Rankov &lt;Branislav.Rankov@arm.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Kevin Brodsky &lt;kevin.brodsky@arm.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some #ifdef CONFIG_KASAN checks are only relevant for software KASAN modes
(either related to shadow memory or compiler instrumentation).  Expand
those into CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS.

Link: https://lkml.kernel.org/r/e6971e432dbd72bb897ff14134ebb7e169bdcf0c.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Signed-off-by: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Reviewed-by: Alexander Potapenko &lt;glider@google.com&gt;
Tested-by: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Branislav Rankov &lt;Branislav.Rankov@arm.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Evgenii Stepanov &lt;eugenis@google.com&gt;
Cc: Kevin Brodsky &lt;kevin.brodsky@arm.com&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Use fallthrough pseudo-keyword</title>
<updated>2020-08-23T22:36:59+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavoars@kernel.org</email>
</author>
<published>2020-08-23T22:36:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=df561f6688fef775baa341a0f5d960becd248b11'/>
<id>df561f6688fef775baa341a0f5d960becd248b11</id>
<content type='text'>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva &lt;gustavoars@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
