<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/riscv/include/asm, branch v6.11</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>riscv: Fix RISCV_ALTERNATIVE_EARLY</title>
<updated>2024-09-03T14:57:55+00:00</updated>
<author>
<name>Alexandre Ghiti</name>
<email>alexghiti@rivosinc.com</email>
</author>
<published>2024-08-29T16:50:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1ff95eb2bebda50c4c5406caaf201e0fcb24cc8f'/>
<id>1ff95eb2bebda50c4c5406caaf201e0fcb24cc8f</id>
<content type='text'>
RISCV_ALTERNATIVE_EARLY will issue sbi_ecall() very early in the boot
process, before the first memory mapping is setup so we can't have any
instrumentation happening here.

In addition, when the kernel is relocatable, we must also not issue any
relocation this early since they would have been patched virtually only.

So, instead of disabling instrumentation for the whole kernel/sbi.c file
and compiling it with -fno-pie, simply move __sbi_ecall() and
__sbi_base_ecall() into their own file where this is fixed.

Reported-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Closes: https://lore.kernel.org/linux-riscv/20240813-pony-truck-3e7a83e9759e@spud/
Reported-by: syzbot+cfbcb82adf6d7279fd35@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-riscv/00000000000065062c061fcec37b@google.com/
Fixes: 1745cfafebdf ("riscv: don't use global static vars to store alternative data")
Signed-off-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20240829165048.49756-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
RISCV_ALTERNATIVE_EARLY will issue sbi_ecall() very early in the boot
process, before the first memory mapping is setup so we can't have any
instrumentation happening here.

In addition, when the kernel is relocatable, we must also not issue any
relocation this early since they would have been patched virtually only.

So, instead of disabling instrumentation for the whole kernel/sbi.c file
and compiling it with -fno-pie, simply move __sbi_ecall() and
__sbi_base_ecall() into their own file where this is fixed.

Reported-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Closes: https://lore.kernel.org/linux-riscv/20240813-pony-truck-3e7a83e9759e@spud/
Reported-by: syzbot+cfbcb82adf6d7279fd35@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-riscv/00000000000065062c061fcec37b@google.com/
Fixes: 1745cfafebdf ("riscv: don't use global static vars to store alternative data")
Signed-off-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20240829165048.49756-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge patch series "riscv: mm: Do not restrict mmap address based on hint"</title>
<updated>2024-08-29T13:22:51+00:00</updated>
<author>
<name>Palmer Dabbelt</name>
<email>palmer@rivosinc.com</email>
</author>
<published>2024-08-29T13:03:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=84cfab9a1805f8e300e945f26e3fdff6d125bc20'/>
<id>84cfab9a1805f8e300e945f26e3fdff6d125bc20</id>
<content type='text'>
Charlie Jenkins &lt;charlie@rivosinc.com&gt; says:

There have been a couple of reports that using the hint address to
restrict the address returned by mmap hint address has caused issues in
applications. A different solution for restricting addresses returned by
mmap is necessary to avoid breakages.

[Palmer: This also just wasn't doing the right thing in the first place,
as it didn't handle the sv39 cases we were trying to deal with.]

* b4-shazam-merge:
  riscv: mm: Do not restrict mmap address based on hint
  riscv: selftests: Remove mmap hint address checks
  Revert "RISC-V: mm: Document mmap changes"

Link: https://lore.kernel.org/r/20240826-riscv_mmap-v1-0-cd8962afe47f@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Charlie Jenkins &lt;charlie@rivosinc.com&gt; says:

There have been a couple of reports that using the hint address to
restrict the address returned by mmap hint address has caused issues in
applications. A different solution for restricting addresses returned by
mmap is necessary to avoid breakages.

[Palmer: This also just wasn't doing the right thing in the first place,
as it didn't handle the sv39 cases we were trying to deal with.]

* b4-shazam-merge:
  riscv: mm: Do not restrict mmap address based on hint
  riscv: selftests: Remove mmap hint address checks
  Revert "RISC-V: mm: Document mmap changes"

Link: https://lore.kernel.org/r/20240826-riscv_mmap-v1-0-cd8962afe47f@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: mm: Do not restrict mmap address based on hint</title>
<updated>2024-08-29T13:03:29+00:00</updated>
<author>
<name>Charlie Jenkins</name>
<email>charlie@rivosinc.com</email>
</author>
<published>2024-08-26T16:36:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2116988d5372aec51f8c4fb85bf8e305ecda47a0'/>
<id>2116988d5372aec51f8c4fb85bf8e305ecda47a0</id>
<content type='text'>
The hint address should not forcefully restrict the addresses returned
by mmap as this causes mmap to report ENOMEM when there is memory still
available.

Signed-off-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Fixes: b5b4287accd7 ("riscv: mm: Use hint address in mmap if available")
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Closes: https://lore.kernel.org/linux-kernel/ZbxTNjQPFKBatMq+@ghost/T/#mccb1890466bf5a488c9ce7441e57e42271895765
Link: https://lore.kernel.org/r/20240826-riscv_mmap-v1-3-cd8962afe47f@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The hint address should not forcefully restrict the addresses returned
by mmap as this causes mmap to report ENOMEM when there is memory still
available.

Signed-off-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Fixes: b5b4287accd7 ("riscv: mm: Use hint address in mmap if available")
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Closes: https://lore.kernel.org/linux-kernel/ZbxTNjQPFKBatMq+@ghost/T/#mccb1890466bf5a488c9ce7441e57e42271895765
Link: https://lore.kernel.org/r/20240826-riscv_mmap-v1-3-cd8962afe47f@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>RISC-V: hwprobe: Add MISALIGNED_PERF key</title>
<updated>2024-08-14T20:13:23+00:00</updated>
<author>
<name>Evan Green</name>
<email>evan@rivosinc.com</email>
</author>
<published>2024-08-09T21:44:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c42e2f076769c9c1bc5f3f0aa1c2032558e76647'/>
<id>c42e2f076769c9c1bc5f3f0aa1c2032558e76647</id>
<content type='text'>
RISCV_HWPROBE_KEY_CPUPERF_0 was mistakenly flagged as a bitmask in
hwprobe_key_is_bitmask(), when in reality it was an enum value. This
causes problems when used in conjunction with RISCV_HWPROBE_WHICH_CPUS,
since SLOW, FAST, and EMULATED have values whose bits overlap with
each other. If the caller asked for the set of CPUs that was SLOW or
EMULATED, the returned set would also include CPUs that were FAST.

Introduce a new hwprobe key, RISCV_HWPROBE_KEY_MISALIGNED_PERF, which
returns the same values in response to a direct query (with no flags),
but is properly handled as an enumerated value. As a result, SLOW,
FAST, and EMULATED are all correctly treated as distinct values under
the new key when queried with the WHICH_CPUS flag.

Leave the old key in place to avoid disturbing applications which may
have already come to rely on the key, with or without its broken
behavior with respect to the WHICH_CPUS flag.

Fixes: e178bf146e4b ("RISC-V: hwprobe: Introduce which-cpus flag")
Signed-off-by: Evan Green &lt;evan@rivosinc.com&gt;
Reviewed-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Reviewed-by: Andrew Jones &lt;ajones@ventanamicro.com&gt;
Link: https://lore.kernel.org/r/20240809214444.3257596-2-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
RISCV_HWPROBE_KEY_CPUPERF_0 was mistakenly flagged as a bitmask in
hwprobe_key_is_bitmask(), when in reality it was an enum value. This
causes problems when used in conjunction with RISCV_HWPROBE_WHICH_CPUS,
since SLOW, FAST, and EMULATED have values whose bits overlap with
each other. If the caller asked for the set of CPUs that was SLOW or
EMULATED, the returned set would also include CPUs that were FAST.

Introduce a new hwprobe key, RISCV_HWPROBE_KEY_MISALIGNED_PERF, which
returns the same values in response to a direct query (with no flags),
but is properly handled as an enumerated value. As a result, SLOW,
FAST, and EMULATED are all correctly treated as distinct values under
the new key when queried with the WHICH_CPUS flag.

Leave the old key in place to avoid disturbing applications which may
have already come to rely on the key, with or without its broken
behavior with respect to the WHICH_CPUS flag.

Fixes: e178bf146e4b ("RISC-V: hwprobe: Introduce which-cpus flag")
Signed-off-by: Evan Green &lt;evan@rivosinc.com&gt;
Reviewed-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Reviewed-by: Andrew Jones &lt;ajones@ventanamicro.com&gt;
Link: https://lore.kernel.org/r/20240809214444.3257596-2-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'riscv-for-linus-6.11-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux</title>
<updated>2024-07-27T17:14:34+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-27T17:14:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c9f33436d85b72b2addfd9423eae864cb8dac1da'/>
<id>c9f33436d85b72b2addfd9423eae864cb8dac1da</id>
<content type='text'>
Pull more RISC-V updates from Palmer Dabbelt:

 - Support for NUMA (via SRAT and SLIT), console output (via SPCR), and
   cache info (via PPTT) on ACPI-based systems.

 - The trap entry/exit code no longer breaks the return address stack
   predictor on many systems, which results in an improvement to trap
   latency.

 - Support for HAVE_ARCH_STACKLEAK.

 - The sv39 linear map has been extended to support 128GiB mappings.

 - The frequency of the mtime CSR is now visible via hwprobe.

* tag 'riscv-for-linus-6.11-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
  RISC-V: Provide the frequency of time CSR via hwprobe
  riscv: Extend sv39 linear mapping max size to 128G
  riscv: enable HAVE_ARCH_STACKLEAK
  riscv: signal: Remove unlikely() from WARN_ON() condition
  riscv: Improve exception and system call latency
  RISC-V: Select ACPI PPTT drivers
  riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT
  riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()
  RISC-V: ACPI: Enable SPCR table for console output on RISC-V
  riscv: boot: remove duplicated targets line
  trace: riscv: Remove deprecated kprobe on ftrace support
  riscv: cpufeature: Extract common elements from extension checking
  riscv: Introduce vendor variants of extension helpers
  riscv: Add vendor extensions to /proc/cpuinfo
  riscv: Extend cpufeature.c to detect vendor extensions
  RISC-V: run savedefconfig for defconfig
  RISC-V: hwprobe: sort EXT_KEY()s in hwprobe_isa_ext0() alphabetically
  ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init
  ACPI: NUMA: change the ACPI_NUMA to a hidden option
  ACPI: NUMA: Add handler for SRAT RINTC affinity structure
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more RISC-V updates from Palmer Dabbelt:

 - Support for NUMA (via SRAT and SLIT), console output (via SPCR), and
   cache info (via PPTT) on ACPI-based systems.

 - The trap entry/exit code no longer breaks the return address stack
   predictor on many systems, which results in an improvement to trap
   latency.

 - Support for HAVE_ARCH_STACKLEAK.

 - The sv39 linear map has been extended to support 128GiB mappings.

 - The frequency of the mtime CSR is now visible via hwprobe.

* tag 'riscv-for-linus-6.11-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
  RISC-V: Provide the frequency of time CSR via hwprobe
  riscv: Extend sv39 linear mapping max size to 128G
  riscv: enable HAVE_ARCH_STACKLEAK
  riscv: signal: Remove unlikely() from WARN_ON() condition
  riscv: Improve exception and system call latency
  RISC-V: Select ACPI PPTT drivers
  riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT
  riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()
  RISC-V: ACPI: Enable SPCR table for console output on RISC-V
  riscv: boot: remove duplicated targets line
  trace: riscv: Remove deprecated kprobe on ftrace support
  riscv: cpufeature: Extract common elements from extension checking
  riscv: Introduce vendor variants of extension helpers
  riscv: Add vendor extensions to /proc/cpuinfo
  riscv: Extend cpufeature.c to detect vendor extensions
  RISC-V: run savedefconfig for defconfig
  RISC-V: hwprobe: sort EXT_KEY()s in hwprobe_isa_ext0() alphabetically
  ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init
  ACPI: NUMA: change the ACPI_NUMA to a hidden option
  ACPI: NUMA: Add handler for SRAT RINTC affinity structure
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux</title>
<updated>2024-07-26T16:50:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-07-26T16:50:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=51c4767503d5d3a5a0ae4dcb19b7f7cf38b40c6c'/>
<id>51c4767503d5d3a5a0ae4dcb19b7f7cf38b40c6c</id>
<content type='text'>
Pull bitmap updates from Yury Norov:
 "Random fixes"

* tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux:
  riscv: Remove unnecessary int cast in variable_fls()
  radix tree test suite: put definition of bitmap_clear() into lib/bitmap.c
  bitops: Add a comment explaining the double underscore macros
  lib: bitmap: add missing MODULE_DESCRIPTION() macros
  cpumask: introduce assign_cpu() macro
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bitmap updates from Yury Norov:
 "Random fixes"

* tag 'bitmap-6.11-rc1' of https://github.com:/norov/linux:
  riscv: Remove unnecessary int cast in variable_fls()
  radix tree test suite: put definition of bitmap_clear() into lib/bitmap.c
  bitops: Add a comment explaining the double underscore macros
  lib: bitmap: add missing MODULE_DESCRIPTION() macros
  cpumask: introduce assign_cpu() macro
</pre>
</div>
</content>
</entry>
<entry>
<title>RISC-V: Provide the frequency of time CSR via hwprobe</title>
<updated>2024-07-26T12:50:51+00:00</updated>
<author>
<name>Palmer Dabbelt</name>
<email>palmer@rivosinc.com</email>
</author>
<published>2024-07-02T03:37:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=52420e483d3e1562f11a208d3c540b27b5e5dbf4'/>
<id>52420e483d3e1562f11a208d3c540b27b5e5dbf4</id>
<content type='text'>
The RISC-V architecture makes a real time counter CSR (via RDTIME
instruction) available for applications in U-mode but there is no
architected mechanism for an application to discover the frequency
the counter is running at. Some applications (e.g., DPDK) use the
time counter for basic performance analysis as well as fine grained
time-keeping.

Add support to the hwprobe system call to export the time CSR
frequency to code running in U-mode.

Signed-off-by: Yunhui Cui &lt;cuiyunhui@bytedance.com&gt;
Reviewed-by: Evan Green &lt;evan@rivosinc.com&gt;
Reviewed-by: Anup Patel &lt;anup@brainfault.org&gt;
Acked-by: Punit Agrawal &lt;punit.agrawal@bytedance.com&gt;
Link: https://lore.kernel.org/r/20240702033731.71955-2-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The RISC-V architecture makes a real time counter CSR (via RDTIME
instruction) available for applications in U-mode but there is no
architected mechanism for an application to discover the frequency
the counter is running at. Some applications (e.g., DPDK) use the
time counter for basic performance analysis as well as fine grained
time-keeping.

Add support to the hwprobe system call to export the time CSR
frequency to code running in U-mode.

Signed-off-by: Yunhui Cui &lt;cuiyunhui@bytedance.com&gt;
Reviewed-by: Evan Green &lt;evan@rivosinc.com&gt;
Reviewed-by: Anup Patel &lt;anup@brainfault.org&gt;
Acked-by: Punit Agrawal &lt;punit.agrawal@bytedance.com&gt;
Link: https://lore.kernel.org/r/20240702033731.71955-2-cuiyunhui@bytedance.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: Extend sv39 linear mapping max size to 128G</title>
<updated>2024-07-26T12:50:50+00:00</updated>
<author>
<name>Stuart Menefy</name>
<email>stuart.menefy@codasip.com</email>
</author>
<published>2024-06-30T11:05:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5c8405d763dc2b125b39166bc70be1b8dcc80582'/>
<id>5c8405d763dc2b125b39166bc70be1b8dcc80582</id>
<content type='text'>
This harmonizes all virtual addressing modes which can now all map
(PGDIR_SIZE * PTRS_PER_PGD) / 4 of physical memory.

The RISCV implementation of KASAN requires that the boundary between
shallow mappings are aligned on an 8G boundary. In this case we need
VMALLOC_START to be 8G aligned. So although we only need to move the
start of the linear mapping down by 4GiB to allow 128GiB to be mapped,
we actually move it down by 8GiB (creating a 4GiB hole between the
linear mapping and KASAN shadow space) to maintain the alignment
requirement.

Signed-off-by: Stuart Menefy &lt;stuart.menefy@codasip.com&gt;
Reviewed-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20240630110550.1731929-1-stuart.menefy@codasip.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This harmonizes all virtual addressing modes which can now all map
(PGDIR_SIZE * PTRS_PER_PGD) / 4 of physical memory.

The RISCV implementation of KASAN requires that the boundary between
shallow mappings are aligned on an 8G boundary. In this case we need
VMALLOC_START to be 8G aligned. So although we only need to move the
start of the linear mapping down by 4GiB to allow 128GiB to be mapped,
we actually move it down by 8GiB (creating a 4GiB hole between the
linear mapping and KASAN shadow space) to maintain the alignment
requirement.

Signed-off-by: Stuart Menefy &lt;stuart.menefy@codasip.com&gt;
Reviewed-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20240630110550.1731929-1-stuart.menefy@codasip.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: enable HAVE_ARCH_STACKLEAK</title>
<updated>2024-07-26T12:50:47+00:00</updated>
<author>
<name>Jisheng Zhang</name>
<email>jszhang@kernel.org</email>
</author>
<published>2024-06-23T23:53:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b5db73fb18257cd5d9cb59bc4b779fffa629566a'/>
<id>b5db73fb18257cd5d9cb59bc4b779fffa629566a</id>
<content type='text'>
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.

At the same time, disables the plugin in EFI stub code because EFI stub
is out of scope for the protection.

Tested on qemu and milkv duo:
/ # echo STACKLEAK_ERASING &gt; /sys/kernel/debug/provoke-crash/DIRECT
[   38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING
[   38.678448] lkdtm: stackleak stack usage:
[   38.678448]   high offset: 288 bytes
[   38.678448]   current:     496 bytes
[   38.678448]   lowest:      1328 bytes
[   38.678448]   tracked:     1328 bytes
[   38.678448]   untracked:   448 bytes
[   38.678448]   poisoned:    14312 bytes
[   38.678448]   low offset:  8 bytes
[   38.689887] lkdtm: OK: the rest of the thread stack is properly erased

Signed-off-by: Jisheng Zhang &lt;jszhang@kernel.org&gt;
Reviewed-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</content>
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<pre>
Add support for the stackleak feature. Whenever the kernel returns to user
space the kernel stack is filled with a poison value.

At the same time, disables the plugin in EFI stub code because EFI stub
is out of scope for the protection.

Tested on qemu and milkv duo:
/ # echo STACKLEAK_ERASING &gt; /sys/kernel/debug/provoke-crash/DIRECT
[   38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING
[   38.678448] lkdtm: stackleak stack usage:
[   38.678448]   high offset: 288 bytes
[   38.678448]   current:     496 bytes
[   38.678448]   lowest:      1328 bytes
[   38.678448]   tracked:     1328 bytes
[   38.678448]   untracked:   448 bytes
[   38.678448]   poisoned:    14312 bytes
[   38.678448]   low offset:  8 bytes
[   38.689887] lkdtm: OK: the rest of the thread stack is properly erased

Signed-off-by: Jisheng Zhang &lt;jszhang@kernel.org&gt;
Reviewed-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
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<entry>
<title>Merge patch series "riscv: Separate vendor extensions from standard extensions"</title>
<updated>2024-07-22T22:37:01+00:00</updated>
<author>
<name>Palmer Dabbelt</name>
<email>palmer@rivosinc.com</email>
</author>
<published>2024-07-22T22:37:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b9a603da42c816af9eeb8f5084ba815353e9b22b'/>
<id>b9a603da42c816af9eeb8f5084ba815353e9b22b</id>
<content type='text'>
Charlie Jenkins &lt;charlie@rivosinc.com&gt; says:

All extensions, both standard and vendor, live in one struct
"riscv_isa_ext". There is currently one vendor extension, xandespmu, but
it is likely that more vendor extensions will be added to the kernel in
the future. As more vendor extensions (and standard extensions) are
added, riscv_isa_ext will become more bloated with a mix of vendor and
standard extensions.

This also allows each vendor to be conditionally enabled through
Kconfig.

* b4-shazam-merge:
  riscv: cpufeature: Extract common elements from extension checking
  riscv: Introduce vendor variants of extension helpers
  riscv: Add vendor extensions to /proc/cpuinfo
  riscv: Extend cpufeature.c to detect vendor extensions

Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-0-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
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<pre>
Charlie Jenkins &lt;charlie@rivosinc.com&gt; says:

All extensions, both standard and vendor, live in one struct
"riscv_isa_ext". There is currently one vendor extension, xandespmu, but
it is likely that more vendor extensions will be added to the kernel in
the future. As more vendor extensions (and standard extensions) are
added, riscv_isa_ext will become more bloated with a mix of vendor and
standard extensions.

This also allows each vendor to be conditionally enabled through
Kconfig.

* b4-shazam-merge:
  riscv: cpufeature: Extract common elements from extension checking
  riscv: Introduce vendor variants of extension helpers
  riscv: Add vendor extensions to /proc/cpuinfo
  riscv: Extend cpufeature.c to detect vendor extensions

Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-0-0af7587bbec0@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
</pre>
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</entry>
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