riscv: Use accessors to page table entries instead of direct dereference

As very well explained in commit 20a004e7b017 ("arm64: mm: Use
READ_ONCE/WRITE_ONCE when accessing page tables"), an architec

riscv: Use accessors to page table entries instead of direct dereference

As very well explained in commit 20a004e7b017 ("arm64: mm: Use
READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose
page table walker can modify the PTE in parallel must use
READ_ONCE()/WRITE_ONCE() macro to avoid any compiler transformation.

So apply that to riscv which is such architecture.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20231213203001.179237-5-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Enable pcpu page first chunk allocator

As explained in commit 6ea529a2037c ("percpu: make embedding first chunk
allocator check vmalloc space size"), the embedding first chunk allocator
needs

riscv: Enable pcpu page first chunk allocator

As explained in commit 6ea529a2037c ("percpu: make embedding first chunk
allocator check vmalloc space size"), the embedding first chunk allocator
needs the vmalloc space to be larger than the maximum distance between
units which are grouped into NUMA nodes.

On a very sparse NUMA configurations and a small vmalloc area (for example,
it is 64GB in sv39), the allocation of dynamic percpu data in the vmalloc
area could fail.

So provide the pcpu page allocator as a fallback in case we fall into
such a sparse configuration (which happened in arm64 as shown by
commit 09cea6195073 ("arm64: support page mapping percpu first chunk
allocator")).

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

show more ...

riscv: Move create_tmp_mapping() to init sections

This function is only used at boot time so mark it as __init.

Fixes: 96f9d4daf745 ("riscv: Rework kasan population functions")
Signed-off-by: Alexa

riscv: Move create_tmp_mapping() to init sections

This function is only used at boot time so mark it as __init.

Fixes: 96f9d4daf745 ("riscv: Rework kasan population functions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230704074357.233982-2-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Mark KASAN tmp* page tables variables as static

tmp_pg_dir, tmp_p4d and tmp_pud are only used in kasan_init.c so they
should be declared as static.

Reported-by: kernel test robot <lkp@intel.

riscv: Mark KASAN tmp* page tables variables as static

tmp_pg_dir, tmp_p4d and tmp_pud are only used in kasan_init.c so they
should be declared as static.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306282202.bODptiGE-lkp@intel.com/
Fixes: 96f9d4daf745 ("riscv: Rework kasan population functions")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230704074357.233982-1-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: mm: fix 2 instances of -Wmissing-variable-declarations

I'm looking to enable -Wmissing-variable-declarations behind W=1. 0day
bot spotted the following instance in ARCH=riscv builds:

arch/

riscv: mm: fix 2 instances of -Wmissing-variable-declarations

I'm looking to enable -Wmissing-variable-declarations behind W=1. 0day
bot spotted the following instance in ARCH=riscv builds:

arch/riscv/mm/init.c:276:7: warning: no previous extern declaration
for non-static variable 'trampoline_pg_dir'
[-Wmissing-variable-declarations]
276 | pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
| ^
arch/riscv/mm/init.c:276:1: note: declare 'static' if the variable is
not intended to be used outside of this translation unit
276 | pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
| ^
arch/riscv/mm/init.c:279:7: warning: no previous extern declaration
for non-static variable 'early_pg_dir'
[-Wmissing-variable-declarations]
279 | pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
| ^
arch/riscv/mm/init.c:279:1: note: declare 'static' if the variable is
not intended to be used outside of this translation unit
279 | pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
| ^

These symbols are referenced by more than one translation unit, so make
sure they're both declared and include the correct header for their
declarations. Finally, sort the list of includes to help keep them tidy.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/llvm/202308081000.tTL1ElTr-lkp@intel.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230808-riscv_static-v2-1-2a1e2d2c7a4f@google.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Rework kasan population functions

Our previous kasan population implementation used to have the final kasan
shadow region mapped with kasan_early_shadow_page, because we did not clean
the ear

riscv: Rework kasan population functions

Our previous kasan population implementation used to have the final kasan
shadow region mapped with kasan_early_shadow_page, because we did not clean
the early mapping and then we had to populate the kasan region "in-place"
which made the code cumbersome.

So now we clear the early mapping, establish a temporary mapping while we
populate the kasan shadow region with just the kernel regions that will
be used.

This new version uses the "generic" way of going through a page table
that may be folded at runtime (avoid the XXX_next macros).

It was tested with outline instrumentation on an Ubuntu kernel
configuration successfully.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230203075232.274282-3-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Split early and final KASAN population functions

This is a preliminary work that allows to make the code more
understandable.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed

riscv: Split early and final KASAN population functions

This is a preliminary work that allows to make the code more
understandable.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230203075232.274282-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: mm: add missing memcpy in kasan_init

Hi Atish,

It seems that the panic is due to the missing memcpy during kasan_init.
Could you please check whether this patch is helpful?

When doing kasan

riscv: mm: add missing memcpy in kasan_init

Hi Atish,

It seems that the panic is due to the missing memcpy during kasan_init.
Could you please check whether this patch is helpful?

When doing kasan_populate, the new allocated base_pud/base_p4d should
contain kasan_early_shadow_{pud, p4d}'s content. Add the missing memcpy
to avoid page fault when read/write kasan shadow region.

Tested on:
- qemu with sv57 and CONFIG_KASAN on.
- qemu with sv48 and CONFIG_KASAN on.

Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Tested-by: Atish Patra <atishp@rivosinc.com>
Fixes: 8fbdccd2b173 ("riscv: mm: Support kasan for sv57")
Link: https://lore.kernel.org/r/20221009083050.3814850-1-panqinglin2020@iscas.ac.cn
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Fix kasan pud population

In sv48, the kasan inner regions are not aligned on PGDIR_SIZE and then
when we populate the kasan linear mapping region, we clear the kasan
vmalloc region which is i

riscv: Fix kasan pud population

In sv48, the kasan inner regions are not aligned on PGDIR_SIZE and then
when we populate the kasan linear mapping region, we clear the kasan
vmalloc region which is in the same PGD.

Fix this by copying the content of the kasan early pud after allocating a
new PGD for the first time.

Fixes: e8a62cc26ddf ("riscv: Implement sv48 support")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Fix config KASAN && SPARSEMEM && !SPARSE_VMEMMAP

In order to get the pfn of a struct page* when sparsemem is enabled
without vmemmap, the mem_section structures need to be initialized which
h

riscv: Fix config KASAN && SPARSEMEM && !SPARSE_VMEMMAP

In order to get the pfn of a struct page* when sparsemem is enabled
without vmemmap, the mem_section structures need to be initialized which
happens in sparse_init.

But kasan_early_init calls pfn_to_page way before sparse_init is called,
which then tries to dereference a null mem_section pointer.

Fix this by removing the usage of this function in kasan_early_init.

Fixes: 8ad8b72721d0 ("riscv: Add KASAN support")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: mm: Support kasan for sv57

This patchset add kasan_populate and kasan_shallow_populate for sv57,
and is tested on both qemu and unmatched with CONFIG_KASAN and
CONFIG_KASAN_VMALLOC on.

Signe

riscv: mm: Support kasan for sv57

This patchset add kasan_populate and kasan_shallow_populate for sv57,
and is tested on both qemu and unmatched with CONFIG_KASAN and
CONFIG_KASAN_VMALLOC on.

Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Implement sv48 support

By adding a new 4th level of page table, give the possibility to 64bit
kernel to address 2^48 bytes of virtual address: in practice, that offers
128TB of virtual addres

riscv: Implement sv48 support

By adding a new 4th level of page table, give the possibility to 64bit
kernel to address 2^48 bytes of virtual address: in practice, that offers
128TB of virtual address space to userspace and allows up to 64TB of
physical memory.

If the underlying hardware does not support sv48, we will automatically
fallback to a standard 3-level page table by folding the new PUD level into
PGDIR level. In order to detect HW capabilities at runtime, we
use SATP feature that ignores writes with an unsupported mode.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Split early kasan mapping to prepare sv48 introduction

Now that kasan shadow region is next to the kernel, for sv48, this
region won't be aligned on PGDIR_SIZE and then when populating this
r

riscv: Split early kasan mapping to prepare sv48 introduction

Now that kasan shadow region is next to the kernel, for sv48, this
region won't be aligned on PGDIR_SIZE and then when populating this
region, we'll need to get down to lower levels of the page table. So
instead of reimplementing the page table walk for the early population,
take advantage of the existing functions used for the final population.

Note that kasan swapper initialization must also be split since memblock
is not initialized at this point and as the last PGD is shared with the
kernel, we'd need to allocate a PUD so postpone the kasan final
population after the kernel population is done.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

show more ...

riscv: Fix asan-stack clang build

Nathan reported that because KASAN_SHADOW_OFFSET was not defined in
Kconfig, it prevents asan-stack from getting disabled with clang even
when CONFIG_KASAN_STACK is

riscv: Fix asan-stack clang build

Nathan reported that because KASAN_SHADOW_OFFSET was not defined in
Kconfig, it prevents asan-stack from getting disabled with clang even
when CONFIG_KASAN_STACK is disabled: fix this by defining the
corresponding config.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Fixes: 8ad8b72721d0 ("riscv: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Do not re-populate shadow memory with kasan_populate_early_shadow

When calling this function, all the shadow memory is already populated
with kasan_early_shadow_pte which has PAGE_KERNEL prot

riscv: Do not re-populate shadow memory with kasan_populate_early_shadow

When calling this function, all the shadow memory is already populated
with kasan_early_shadow_pte which has PAGE_KERNEL protection.
kasan_populate_early_shadow write-protects the mapping of the range
of addresses passed in argument in zero_pte_populate, which actually
write-protects all the shadow memory mapping since kasan_early_shadow_pte
is used for all the shadow memory at this point. And then when using
memblock API to populate the shadow memory, the first write access to the
kernel stack triggers a trap. This becomes visible with the next commit
that contains a fix for asan-stack.

We already manually populate all the shadow memory in kasan_early_init
and we write-protect kasan_early_shadow_pte at the end of kasan_init
which makes the calls to kasan_populate_early_shadow superfluous so
we can remove them.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Fixes: e178d670f251 ("riscv/kasan: add KASAN_VMALLOC support")
Fixes: 8ad8b72721d0 ("riscv: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Ensure BPF_JIT_REGION_START aligned with PMD size

Andreas reported commit fc8504765ec5 ("riscv: bpf: Avoid breaking W^X")
breaks booting with one kind of defconfig, I reproduced a kernel pani

riscv: Ensure BPF_JIT_REGION_START aligned with PMD size

Andreas reported commit fc8504765ec5 ("riscv: bpf: Avoid breaking W^X")
breaks booting with one kind of defconfig, I reproduced a kernel panic
with the defconfig:

[ 0.138553] Unable to handle kernel paging request at virtual address ffffffff81201220
[ 0.139159] Oops [#1]
[ 0.139303] Modules linked in:
[ 0.139601] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5-default+ #1
[ 0.139934] Hardware name: riscv-virtio,qemu (DT)
[ 0.140193] epc : __memset+0xc4/0xfc
[ 0.140416] ra : skb_flow_dissector_init+0x1e/0x82
[ 0.140609] epc : ffffffff8029806c ra : ffffffff8033be78 sp : ffffffe001647da0
[ 0.140878] gp : ffffffff81134b08 tp : ffffffe001654380 t0 : ffffffff81201158
[ 0.141156] t1 : 0000000000000002 t2 : 0000000000000154 s0 : ffffffe001647dd0
[ 0.141424] s1 : ffffffff80a43250 a0 : ffffffff81201220 a1 : 0000000000000000
[ 0.141654] a2 : 000000000000003c a3 : ffffffff81201258 a4 : 0000000000000064
[ 0.141893] a5 : ffffffff8029806c a6 : 0000000000000040 a7 : ffffffffffffffff
[ 0.142126] s2 : ffffffff81201220 s3 : 0000000000000009 s4 : ffffffff81135088
[ 0.142353] s5 : ffffffff81135038 s6 : ffffffff8080ce80 s7 : ffffffff80800438
[ 0.142584] s8 : ffffffff80bc6578 s9 : 0000000000000008 s10: ffffffff806000ac
[ 0.142810] s11: 0000000000000000 t3 : fffffffffffffffc t4 : 0000000000000000
[ 0.143042] t5 : 0000000000000155 t6 : 00000000000003ff
[ 0.143220] status: 0000000000000120 badaddr: ffffffff81201220 cause: 000000000000000f
[ 0.143560] [<ffffffff8029806c>] __memset+0xc4/0xfc
[ 0.143859] [<ffffffff8061e984>] init_default_flow_dissectors+0x22/0x60
[ 0.144092] [<ffffffff800010fc>] do_one_initcall+0x3e/0x168
[ 0.144278] [<ffffffff80600df0>] kernel_init_freeable+0x1c8/0x224
[ 0.144479] [<ffffffff804868a8>] kernel_init+0x12/0x110
[ 0.144658] [<ffffffff800022de>] ret_from_exception+0x0/0xc
[ 0.145124] ---[ end trace f1e9643daa46d591 ]---

After some investigation, I think I found the root cause: commit
2bfc6cd81bd ("move kernel mapping outside of linear mapping") moves
BPF JIT region after the kernel:

| #define BPF_JIT_REGION_START PFN_ALIGN((unsigned long)&_end)

The &_end is unlikely aligned with PMD size, so the front bpf jit
region sits with part of kernel .data section in one PMD size mapping.
But kernel is mapped in PMD SIZE, when bpf_jit_binary_lock_ro() is
called to make the first bpf jit prog ROX, we will make part of kernel
.data section RO too, so when we write to, for example memset the
.data section, MMU will trigger a store page fault.

To fix the issue, we need to ensure the BPF JIT region is PMD size
aligned. This patch acchieve this goal by restoring the BPF JIT region
to original position, I.E the 128MB before kernel .text section. The
modification to kasan_init.c is inspired by Alexandre.

Fixes: fc8504765ec5 ("riscv: bpf: Avoid breaking W^X")
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: kasan: Fix MODULES_VADDR evaluation due to local variables' name

commit 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear
mapping") makes use of MODULES_VADDR to populate kernel, BP

riscv: kasan: Fix MODULES_VADDR evaluation due to local variables' name

commit 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear
mapping") makes use of MODULES_VADDR to populate kernel, BPF, modules
mapping. Currently, MODULES_VADDR is defined as below for RV64:

| #define MODULES_VADDR (PFN_ALIGN((unsigned long)&_end) - SZ_2G)

But kasan_init() has two local variables which are also named as _start,
_end, so MODULES_VADDR is evaluated with the local variable _end
rather than the global "_end" as we expected. Fix this issue by
renaming the two local variables.

Fixes: 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: add __init section marker to some functions

They are not needed after booting, so mark them as __init to move them
to the __init section.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Si

riscv: add __init section marker to some functions

They are not needed after booting, so mark them as __init to move them
to the __init section.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Move kernel mapping outside of linear mapping

This is a preparatory patch for relocatable kernel and sv48 support.

The kernel used to be linked at PAGE_OFFSET address therefore we could use

riscv: Move kernel mapping outside of linear mapping

This is a preparatory patch for relocatable kernel and sv48 support.

The kernel used to be linked at PAGE_OFFSET address therefore we could use
the linear mapping for the kernel mapping. But the relocated kernel base
address will be different from PAGE_OFFSET and since in the linear mapping,
two different virtual addresses cannot point to the same physical address,
the kernel mapping needs to lie outside the linear mapping so that we don't
have to copy it at the same physical offset.

The kernel mapping is moved to the last 2GB of the address space, BPF
is now always after the kernel and modules use the 2GB memory range right
before the kernel, so BPF and modules regions do not overlap. KASLR
implementation will simply have to move the kernel in the last 2GB range
and just take care of leaving enough space for BPF.

In addition, by moving the kernel to the end of the address space, both
sv39 and sv48 kernels will be exactly the same without needing to be
relocated at runtime.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: Squash the STRICT_RWX fix, and a !MMU fix]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: remove unneeded semicolon

Eliminate the following coccicheck warning:
./arch/riscv/mm/kasan_init.c:219:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-b

riscv: remove unneeded semicolon

Eliminate the following coccicheck warning:
./arch/riscv/mm/kasan_init.c:219:2-3: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Cleanup KASAN_VMALLOC support

When KASAN vmalloc region is populated, there is no userspace process and
the page table in use is swapper_pg_dir, so there is no need to read
SATP. Then we can

riscv: Cleanup KASAN_VMALLOC support

When KASAN vmalloc region is populated, there is no userspace process and
the page table in use is swapper_pg_dir, so there is no need to read
SATP. Then we can use the same scheme used by kasan_populate_p*d
functions to go through the page table, which harmonizes the code.

In addition, make use of set_pgd that goes through all unused page table
levels, contrary to p*d_populate functions, which makes this function work
whatever the number of page table levels.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

RISC-V: kasan: Declare kasan_shallow_populate() static

Without this I get a missing prototype warning.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: e178d670f251 ("riscv/kasan: add KASAN_VM

RISC-V: kasan: Declare kasan_shallow_populate() static

Without this I get a missing prototype warning.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: e178d670f251 ("riscv/kasan: add KASAN_VMALLOC support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Ensure page table writes are flushed when initializing KASAN vmalloc

Make sure that writes to kernel page table during KASAN vmalloc
initialization are made visible by adding a sfence.vma.

S

riscv: Ensure page table writes are flushed when initializing KASAN vmalloc

Make sure that writes to kernel page table during KASAN vmalloc
initialization are made visible by adding a sfence.vma.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Fixes: e178d670f251 ("riscv/kasan: add KASAN_VMALLOC support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Improve kasan population by using hugepages when possible

The kasan functions that populates the shadow regions used to allocate them
page by page and did not take advantage of hugepages, so

riscv: Improve kasan population by using hugepages when possible

The kasan functions that populates the shadow regions used to allocate them
page by page and did not take advantage of hugepages, so fix this by
trying to allocate hugepages of 1GB and fallback to 2MB hugepages or 4K
pages in case it fails.

This reduces the page table memory consumption and improves TLB usage,
as shown below:

Before this patch:

---[ Kasan shadow start ]---
0xffffffc000000000-0xffffffc400000000 0x00000000818ef000 16G PTE . A . . . . R V
0xffffffc400000000-0xffffffc447fc0000 0x00000002b7f4f000 1179392K PTE D A . . . W R V
0xffffffc480000000-0xffffffc800000000 0x00000000818ef000 14G PTE . A . . . . R V
---[ Kasan shadow end ]---

After this patch:

---[ Kasan shadow start ]---
0xffffffc000000000-0xffffffc400000000 0x00000000818ef000 16G PTE . A . . . . R V
0xffffffc400000000-0xffffffc440000000 0x0000000240000000 1G PGD D A . . . W R V
0xffffffc440000000-0xffffffc447e00000 0x00000002b7e00000 126M PMD D A . . . W R V
0xffffffc447e00000-0xffffffc447fc0000 0x00000002b818f000 1792K PTE D A . . . W R V
0xffffffc480000000-0xffffffc800000000 0x00000000818ef000 14G PTE . A . . . . R V
---[ Kasan shadow end ]---

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

show more ...

riscv: Improve kasan population function

Current population code populates a whole page table without taking care
of what could have been already allocated and without taking into account
possible i

riscv: Improve kasan population function

Current population code populates a whole page table without taking care
of what could have been already allocated and without taking into account
possible index in page table, assuming the virtual address to map is always
aligned on the page table size, which, for example, won't be the case when
the kernel will get pushed to the end of the address space.

Address those problems by rewriting the kasan population function,
splitting it into subfunctions for each different page table level.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

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