linux.git/arch/riscv/kernel/vmlinux.lds.S, branch v5.12 Linux kernel source tree RISC-V: Move dynamic relocation section under __init 2020-11-26T00:05:29+00:00 Atish Patra atish.patra@wdc.com 2020-11-05T00:04:39+00:00 b5b11a8ac4b5a997a1b3ae388aea3879e26c857f Dynamic relocation section are only required during boot. Those sections can be freed after init. Thus, it can be moved to __init section. Signed-off-by: Atish Patra <atish.patra@wdc.com> Tested-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
Dynamic relocation section are only required during boot. Those sections
can be freed after init. Thus, it can be moved to __init section.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
RISC-V: Protect all kernel sections including init early 2020-11-26T00:05:28+00:00 Atish Patra atish.patra@wdc.com 2020-11-05T00:04:38+00:00 19a00869028f4a28a36f90649166631dff6e3ccd Currently, .init.text & .init.data are intermixed which makes it impossible apply different permissions to them. .init.data shouldn't need exec permissions while .init.text shouldn't have write permission. Moreover, the strict permission are only enforced /init starts. This leaves the kernel vulnerable from possible buggy built-in modules. Keep .init.text & .data in separate sections so that different permissions are applied to each section. Apply permissions to individual sections as early as possible. This improves the kernel protection under CONFIG_STRICT_KERNEL_RWX. We also need to restore the permissions for the entire _init section after it is freed so that those pages can be used for other purpose. Signed-off-by: Atish Patra <atish.patra@wdc.com> Tested-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
Currently, .init.text & .init.data are intermixed which makes it impossible
apply different permissions to them. .init.data shouldn't need exec
permissions while .init.text shouldn't have write permission. Moreover,
the strict permission are only enforced /init starts. This leaves the
kernel vulnerable from possible buggy built-in modules.

Keep .init.text & .data in separate sections so that different permissions
are applied to each section. Apply permissions to individual sections as
early as possible. This improves the kernel protection under
CONFIG_STRICT_KERNEL_RWX. We also need to restore the permissions for the
entire _init section after it is freed so that those pages can be used
for other purpose.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
RISC-V: Align the .init.text section 2020-11-26T00:05:27+00:00 Atish Patra atish.patra@wdc.com 2020-11-05T00:04:37+00:00 b6566dc1acca38ce6ed845ce8a270fb181ff6d41 In order to improve kernel text protection, we need separate .init.text/ .init.data/.text in separate sections. However, RISC-V linker relaxation code is not aware of any alignment between sections. As a result, it may relax any RISCV_CALL relocations between sections to JAL without realizing that an inter section alignment may move the address farther. That may lead to a relocation truncated fit error. However, linker relaxation code is aware of the individual section alignments. The detailed discussion on this issue can be found here. https://github.com/riscv/riscv-gnu-toolchain/issues/738 Keep the .init.text section aligned so that linker relaxation will take that as a hint while relaxing inter section calls. Here are the code size changes for each section because of this change. section change in size (in bytes) .head.text +4 .text +40 .init.text +6530 .exit.text +84 The only significant increase in size happened for .init.text because all intra relocations also use 2MB alignment. Suggested-by: Jim Wilson <jimw@sifive.com> Signed-off-by: Atish Patra <atish.patra@wdc.com> Tested-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
In order to improve kernel text protection, we need separate .init.text/
.init.data/.text in separate sections. However, RISC-V linker relaxation
code is not aware of any alignment between sections. As a result, it may
relax any RISCV_CALL relocations between sections to JAL without realizing
that an inter section alignment may move the address farther. That may
lead to a relocation truncated fit error. However, linker relaxation code
is aware of the individual section alignments.

The detailed discussion on this issue can be found here.
https://github.com/riscv/riscv-gnu-toolchain/issues/738

Keep the .init.text section aligned so that linker relaxation will take
that as a hint while relaxing inter section calls.
Here are the code size changes for each section because of this change.

section         change in size (in bytes)
  .head.text      +4
  .text           +40
  .init.text      +6530
  .exit.text      +84

The only significant increase in size happened for .init.text because
all intra relocations also use 2MB alignment.

Suggested-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Merge tag 'riscv-for-linus-5.10-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux 2020-10-20T01:18:30+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-10-20T01:18:30+00:00 270315b8235e3d10c2e360cff56c2f9e0915a252 Pull RISC-V updates from Palmer Dabbelt: "A handful of cleanups and new features: - A handful of cleanups for our page fault handling - Improvements to how we fill out cacheinfo - Support for EFI-based systems" * tag 'riscv-for-linus-5.10-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (22 commits) RISC-V: Add page table dump support for uefi RISC-V: Add EFI runtime services RISC-V: Add EFI stub support. RISC-V: Add PE/COFF header for EFI stub RISC-V: Implement late mapping page table allocation functions RISC-V: Add early ioremap support RISC-V: Move DT mapping outof fixmap RISC-V: Fix duplicate included thread_info.h riscv/mm/fault: Set FAULT_FLAG_INSTRUCTION flag in do_page_fault() riscv/mm/fault: Fix inline placement in vmalloc_fault() declaration riscv: Add cache information in AUX vector riscv: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO riscv: Set more data to cacheinfo riscv/mm/fault: Move access error check to function riscv/mm/fault: Move FAULT_FLAG_WRITE handling in do_page_fault() riscv/mm/fault: Simplify mm_fault_error() riscv/mm/fault: Move fault error handling to mm_fault_error() riscv/mm/fault: Simplify fault error handling riscv/mm/fault: Move vmalloc fault handling to vmalloc_fault() riscv/mm/fault: Move bad area handling to bad_area() ... 
Pull RISC-V updates from Palmer Dabbelt:
 "A handful of cleanups and new features:

   - A handful of cleanups for our page fault handling

   - Improvements to how we fill out cacheinfo

   - Support for EFI-based systems"

* tag 'riscv-for-linus-5.10-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (22 commits)
  RISC-V: Add page table dump support for uefi
  RISC-V: Add EFI runtime services
  RISC-V: Add EFI stub support.
  RISC-V: Add PE/COFF header for EFI stub
  RISC-V: Implement late mapping page table allocation functions
  RISC-V: Add early ioremap support
  RISC-V: Move DT mapping outof fixmap
  RISC-V: Fix duplicate included thread_info.h
  riscv/mm/fault: Set FAULT_FLAG_INSTRUCTION flag in do_page_fault()
  riscv/mm/fault: Fix inline placement in vmalloc_fault() declaration
  riscv: Add cache information in AUX vector
  riscv: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO
  riscv: Set more data to cacheinfo
  riscv/mm/fault: Move access error check to function
  riscv/mm/fault: Move FAULT_FLAG_WRITE handling in do_page_fault()
  riscv/mm/fault: Simplify mm_fault_error()
  riscv/mm/fault: Move fault error handling to mm_fault_error()
  riscv/mm/fault: Simplify fault error handling
  riscv/mm/fault: Move vmalloc fault handling to vmalloc_fault()
  riscv/mm/fault: Move bad area handling to bad_area()
  ...
Merge tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-10-12T20:39:19+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-10-12T20:39:19+00:00 34eb62d868d729e9a252aa497277081fb652eeed Pull orphan section checking from Ingo Molnar: "Orphan link sections were a long-standing source of obscure bugs, because the heuristics that various linkers & compilers use to handle them (include these bits into the output image vs discarding them silently) are both highly idiosyncratic and also version dependent. Instead of this historically problematic mess, this tree by Kees Cook (et al) adds build time asserts and build time warnings if there's any orphan section in the kernel or if a section is not sized as expected. And because we relied on so many silent assumptions in this area, fix a metric ton of dependencies and some outright bugs related to this, before we can finally enable the checks on the x86, ARM and ARM64 platforms" * tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/boot/compressed: Warn on orphan section placement x86/build: Warn on orphan section placement arm/boot: Warn on orphan section placement arm/build: Warn on orphan section placement arm64/build: Warn on orphan section placement x86/boot/compressed: Add missing debugging sections to output x86/boot/compressed: Remove, discard, or assert for unwanted sections x86/boot/compressed: Reorganize zero-size section asserts x86/build: Add asserts for unwanted sections x86/build: Enforce an empty .got.plt section x86/asm: Avoid generating unused kprobe sections arm/boot: Handle all sections explicitly arm/build: Assert for unwanted sections arm/build: Add missing sections arm/build: Explicitly keep .ARM.attributes sections arm/build: Refactor linker script headers arm64/build: Assert for unwanted sections arm64/build: Add missing DWARF sections arm64/build: Use common DISCARDS in linker script arm64/build: Remove .eh_frame* sections due to unwind tables ... 
Pull orphan section checking from Ingo Molnar:
 "Orphan link sections were a long-standing source of obscure bugs,
  because the heuristics that various linkers & compilers use to handle
  them (include these bits into the output image vs discarding them
  silently) are both highly idiosyncratic and also version dependent.

  Instead of this historically problematic mess, this tree by Kees Cook
  (et al) adds build time asserts and build time warnings if there's any
  orphan section in the kernel or if a section is not sized as expected.

  And because we relied on so many silent assumptions in this area, fix
  a metric ton of dependencies and some outright bugs related to this,
  before we can finally enable the checks on the x86, ARM and ARM64
  platforms"

* tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/boot/compressed: Warn on orphan section placement
  x86/build: Warn on orphan section placement
  arm/boot: Warn on orphan section placement
  arm/build: Warn on orphan section placement
  arm64/build: Warn on orphan section placement
  x86/boot/compressed: Add missing debugging sections to output
  x86/boot/compressed: Remove, discard, or assert for unwanted sections
  x86/boot/compressed: Reorganize zero-size section asserts
  x86/build: Add asserts for unwanted sections
  x86/build: Enforce an empty .got.plt section
  x86/asm: Avoid generating unused kprobe sections
  arm/boot: Handle all sections explicitly
  arm/build: Assert for unwanted sections
  arm/build: Add missing sections
  arm/build: Explicitly keep .ARM.attributes sections
  arm/build: Refactor linker script headers
  arm64/build: Assert for unwanted sections
  arm64/build: Add missing DWARF sections
  arm64/build: Use common DISCARDS in linker script
  arm64/build: Remove .eh_frame* sections due to unwind tables
  ...
riscv: Fixup bootup failure with HARDENED_USERCOPY 2020-10-07T01:34:00+00:00 Guo Ren guoren@linux.alibaba.com 2020-10-06T16:49:33+00:00 84814460eef9af0fb56a4698341c9cb7996a6312 6184358da000 ("riscv: Fixup static_obj() fail") attempted to elide a lockdep failure by rearranging our kernel image to place all initdata within [_stext, _end], thus triggering lockdep to treat these as static objects. These objects are released and eventually reallocated, causing check_kernel_text_object() to trigger a BUG(). This backs out the change to make [_stext, _end] all-encompassing, instead just moving initdata. This results in initdata being outside of [__init_begin, __init_end], which means initdata can't be freed. Link: https://lore.kernel.org/linux-riscv/1593266228-61125-1-git-send-email-guoren@kernel.org/T/#t Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Reported-by: Aurelien Jarno <aurelien@aurel32.net> Tested-by: Aurelien Jarno <aurelien@aurel32.net> [Palmer: Clean up commit text] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
6184358da000 ("riscv: Fixup static_obj() fail") attempted to elide a lockdep
failure by rearranging our kernel image to place all initdata within [_stext,
_end], thus triggering lockdep to treat these as static objects.  These objects
are released and eventually reallocated, causing check_kernel_text_object() to
trigger a BUG().

This backs out the change to make [_stext, _end] all-encompassing, instead just
moving initdata.  This results in initdata being outside of [__init_begin,
__init_end], which means initdata can't be freed.

Link: https://lore.kernel.org/linux-riscv/1593266228-61125-1-git-send-email-guoren@kernel.org/T/#t
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reported-by: Aurelien Jarno <aurelien@aurel32.net>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
[Palmer: Clean up commit text]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
RISC-V: Add PE/COFF header for EFI stub 2020-10-02T21:31:16+00:00 Atish Patra atish.patra@wdc.com 2020-09-17T22:37:13+00:00 cb7d2dd5612a77a2597c00fce770a52c921e2ea5 Linux kernel Image can appear as an EFI application With appropriate PE/COFF header fields in the beginning of the Image header. An EFI application loader can directly load a Linux kernel Image and an EFI stub residing in kernel can boot Linux kernel directly. Add the necessary PE/COFF header. Signed-off-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com [ardb: - use C prefix for c.li to ensure the expected opcode is emitted - align all image sections according to PE/COFF section alignment ] Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
Linux kernel Image can appear as an EFI application With appropriate
PE/COFF header fields in the beginning of the Image header. An EFI
application loader can directly load a Linux kernel Image and an EFI
stub residing in kernel can boot Linux kernel directly.

Add the necessary PE/COFF header.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200421033336.9663-3-atish.patra@wdc.com
[ardb: - use C prefix for c.li to ensure the expected opcode is emitted
       - align all image sections according to PE/COFF section alignment ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG 2020-09-01T07:50:35+00:00 Kees Cook keescook@chromium.org 2020-08-21T19:42:45+00:00 c604abc3f6e3030f3a3022b184ed7d3780c34d30 The .comment section doesn't belong in STABS_DEBUG. Split it out into a new macro named ELF_DETAILS. This will gain other non-debug sections that need to be accounted for when linking with --orphan-handling=warn. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-arch@vger.kernel.org Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org 
The .comment section doesn't belong in STABS_DEBUG. Split it out into a
new macro named ELF_DETAILS. This will gain other non-debug sections
that need to be accounted for when linking with --orphan-handling=warn.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org
riscv: Fixup static_obj() fail 2020-07-30T18:37:21+00:00 Guo Ren guoren@linux.alibaba.com 2020-06-27T13:57:06+00:00 6184358da0004c8fd940afda6c0a0fa4027dc911 When enable LOCKDEP, static_obj() will cause error. Because some __initdata static variables is before _stext: static int static_obj(const void *obj) { unsigned long start = (unsigned long) &_stext, end = (unsigned long) &_end, addr = (unsigned long) obj; /* * static variable? */ if ((addr >= start) && (addr < end)) return 1; [ 0.067192] INFO: trying to register non-static key. [ 0.067325] the code is fine but needs lockdep annotation. [ 0.067449] turning off the locking correctness validator. [ 0.067718] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc7-dirty #44 [ 0.067945] Call Trace: [ 0.068369] [<ffffffe00020323c>] walk_stackframe+0x0/0xa4 [ 0.068506] [<ffffffe000203422>] show_stack+0x2a/0x34 [ 0.068631] [<ffffffe000521e4e>] dump_stack+0x94/0xca [ 0.068757] [<ffffffe000255a4e>] register_lock_class+0x5b8/0x5bc [ 0.068969] [<ffffffe000255abe>] __lock_acquire+0x6c/0x1d5c [ 0.069101] [<ffffffe0002550fe>] lock_acquire+0xae/0x312 [ 0.069228] [<ffffffe000989a8e>] _raw_spin_lock_irqsave+0x40/0x5a [ 0.069357] [<ffffffe000247c64>] complete+0x1e/0x50 [ 0.069479] [<ffffffe000984c38>] rest_init+0x1b0/0x28a [ 0.069660] [<ffffffe0000016a2>] 0xffffffe0000016a2 [ 0.069779] [<ffffffe000001b84>] 0xffffffe000001b84 [ 0.069953] [<ffffffe000001092>] 0xffffffe000001092 static __initdata DECLARE_COMPLETION(kthreadd_done); noinline void __ref rest_init(void) { ... complete(&kthreadd_done); Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
When enable LOCKDEP, static_obj() will cause error. Because some
__initdata static variables is before _stext:

static int static_obj(const void *obj)
{
        unsigned long start = (unsigned long) &_stext,
                      end   = (unsigned long) &_end,
                      addr  = (unsigned long) obj;

        /*
         * static variable?
         */
        if ((addr >= start) && (addr < end))
                return 1;

[    0.067192] INFO: trying to register non-static key.
[    0.067325] the code is fine but needs lockdep annotation.
[    0.067449] turning off the locking correctness validator.
[    0.067718] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc7-dirty #44
[    0.067945] Call Trace:
[    0.068369] [<ffffffe00020323c>] walk_stackframe+0x0/0xa4
[    0.068506] [<ffffffe000203422>] show_stack+0x2a/0x34
[    0.068631] [<ffffffe000521e4e>] dump_stack+0x94/0xca
[    0.068757] [<ffffffe000255a4e>] register_lock_class+0x5b8/0x5bc
[    0.068969] [<ffffffe000255abe>] __lock_acquire+0x6c/0x1d5c
[    0.069101] [<ffffffe0002550fe>] lock_acquire+0xae/0x312
[    0.069228] [<ffffffe000989a8e>] _raw_spin_lock_irqsave+0x40/0x5a
[    0.069357] [<ffffffe000247c64>] complete+0x1e/0x50
[    0.069479] [<ffffffe000984c38>] rest_init+0x1b0/0x28a
[    0.069660] [<ffffffe0000016a2>] 0xffffffe0000016a2
[    0.069779] [<ffffffe000001b84>] 0xffffffe000001b84
[    0.069953] [<ffffffe000001092>] 0xffffffe000001092

static __initdata DECLARE_COMPLETION(kthreadd_done);

noinline void __ref rest_init(void)
{
	...
	complete(&kthreadd_done);

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
riscv: Allow device trees to be built into the kernel 2020-05-18T18:38:05+00:00 Palmer Dabbelt palmerdabbelt@google.com 2020-04-14T04:43:24+00:00 2d2682512f0faf4d09a696184bf3c0bb6838baca Some systems don't provide a useful device tree to the kernel on boot. Chasing around bootloaders for these systems is a headache, so instead le't's just keep a device tree table in the kernel, keyed by the SOC's unique identifier, that contains the relevant DTB. This is only implemented for M mode right now. While we could implement this via the SBI calls that allow access to these identifiers, we don't have any systems that need this right now. Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> 
Some systems don't provide a useful device tree to the kernel on boot.
Chasing around bootloaders for these systems is a headache, so instead
le't's just keep a device tree table in the kernel, keyed by the SOC's
unique identifier, that contains the relevant DTB.

This is only implemented for M mode right now. While we could implement
this via the SBI calls that allow access to these identifiers, we don't
have any systems that need this right now.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>