Probing for misaligned access speed takes about 0.06 seconds. On a
system with 64 cores, doing this in smp_callin() means it's done
serially, extending boot time by 3.8 seconds. That's a lot of boot time.

Instead of measuring each CPU serially, let's do the measurements on
all CPUs in parallel. If we disable preemption on all CPUs, the
jiffies stop ticking, so we can do this in stages of 1) everybody
except core 0, then 2) core 0. The allocations are all done outside of
on_each_cpu() to avoid calling alloc_pages() with interrupts disabled.

For hotplugged CPUs that come in after the boot time measurement,
register CPU hotplug callbacks, and do the measurement there. Interrupts
are enabled in those callbacks, so they're fine to do alloc_pages() in.
Reported-by: Jisheng Zhang <jszhang@kernel.org>
Closes: https://lore.kernel.org/all/mhng-9359993d-6872-4134-83ce-c97debe1cf9a@palmer-ri-x1c9/T/#mae9b8f40016f9df428829d33360144dc5026bcbf
Fixes: 584ea656 ("RISC-V: Probe for unaligned access speed")
Signed-off-by: Evan Green <evan@rivosinc.com>
Link: https://lore.kernel.org/r/20231106225855.3121724-1-evan@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This function shouldn't be __init, since it's called during hotplug. The
warning says it well enough:

WARNING: modpost: vmlinux: section mismatch in reference:
check_unaligned_access_all_cpus+0x13a (section: .text) ->
unaligned_emulation_finish (section: .init.text)
Signed-off-by: Evan Green <evan@rivosinc.com>
Fixes: 71c54b3d ("riscv: report misaligned accesses emulation to hwprobe")
Link: https://lore.kernel.org/r/20231106231105.3141413-1-evan@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

In /proc/cpuinfo, most of the information we show for each processor is
specific to that hart: marchid, mvendorid, mimpid, processor, hart,
compatible, and the mmu size. But the ISA string gets filtered through a
lowest common denominator mask, so that if one CPU is missing an ISA
extension, no CPUs will show it.

Now that we track the ISA extensions for each hart, let's report ISA
extension info accurately per-hart in /proc/cpuinfo. We cannot change
the "isa:" line, as usermode may be relying on that line to show only
the common set of extensions supported across all harts. Add a new "hart
isa" line instead, which reports the true set of extensions for that
hart.
Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231106232439.3176268-1-evan@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Without this I get a bunch of warnings along the lines of

    arch/riscv/kernel/module.c:535:26: error: positional initialization of field in 'struct' declared with 'designated_init' attribute [-Werror=designated-init]
      535 |         [R_RISCV_32] = { apply_r_riscv_32_rela },

This just mades the member initializers explicit instead of positional.
I also aligned some of the table, but mostly just to make the batch
editing go faster.

Fixes: b51fc88c ("Merge patch series "riscv: Add remaining module relocations and tests"")
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231107155529.8368-1-palmer@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Charlie Jenkins <charlie@rivosinc.com> says:

A handful of module relocations were missing, this patch includes the
remaining ones. I also wrote some test cases to ensure that module
loading works properly. Some relocations cannot be supported in the
kernel, these include the ones that rely on thread local storage and
dynamic linking.

This patch also overhauls the implementation of ADD/SUB/SET/ULEB128
relocations to handle overflow. "Overflow" is different for ULEB128
since it is a variable-length encoding that the compiler can be expected
to generate enough space for. Instead of overflowing, ULEB128 will
expand into the next 8-bit segment of the location.

A psABI proposal [1] was merged that mandates that SET_ULEB128 and
SUB_ULEB128 are paired, however the discussion following the merging of
the pull request revealed that while the pull request was valid, it
would be better for linkers to properly handle this overflow. This patch
proactively implements this methodology for future compatibility.

This can be tested by enabling KUNIT, RUNTIME_KERNEL_TESTING_MENU, and
RISCV_MODULE_LINKING_KUNIT.

[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc/pull/403

* b4-shazam-merge:
  riscv: Add tests for riscv module loading
  riscv: Add remaining module relocations
  riscv: Avoid unaligned access when relocating modules

Link: https://lore.kernel.org/r/20231101-module_relocations-v9-0-8dfa3483c400@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add test cases for the two main groups of relocations added: SUB and
SET, along with uleb128.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231101-module_relocations-v9-3-8dfa3483c400@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add all final module relocations and add error logs explaining the ones
that are not supported. Implement overflow checks for
ADD/SUB/SET/ULEB128 relocations.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231101-module_relocations-v9-2-8dfa3483c400@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

With the C-extension regular 32bit instructions are not
necessarily aligned on 4-byte boundaries. RISC-V instructions
are in fact an ordered list of 16bit little-endian
"parcels", so access the instruction as such.

This should also make the code work in case someone builds
a big-endian RISC-V machine.
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231101-module_relocations-v9-1-8dfa3483c400@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

The cache ops are also used by the pmem code which is unconditionally
built into the kernel.  Move them into a separate file that is built
based on the correct config option.

Fixes: fd962781 ("riscv: RISCV_NONSTANDARD_CACHE_OPS shouldn't depend on RISCV_DMA_NONCOHERENT")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> #
Link: https://lore.kernel.org/r/20231028155101.1039049-1-hch@lst.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Alexandre Ghiti <alexghiti@rivosinc.com> says:

This series optimizes the tlb flushes on riscv which used to simply
flush the whole tlb whatever the size of the range to flush or the size
of the stride.

Patch 3 introduces a threshold that is microarchitecture specific and
will very likely be modified by vendors, not sure though which mechanism
we'll use to do that (dt? alternatives? vendor initialization code?).

* b4-shazam-merge:
  riscv: Improve flush_tlb_kernel_range()
  riscv: Make __flush_tlb_range() loop over pte instead of flushing the whole tlb
  riscv: Improve flush_tlb_range() for hugetlb pages
  riscv: Improve tlb_flush()

Link: https://lore.kernel.org/r/20231030133027.19542-1-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This function used to simply flush the whole tlb of all harts, be more
subtile and try to only flush the range.

The problem is that we can only use PAGE_SIZE as stride since we don't know
the size of the underlying mapping and then this function will be improved
only if the size of the region to flush is < threshold * PAGE_SIZE.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231030133027.19542-5-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Currently, when the range to flush covers more than one page (a 4K page or
a hugepage), __flush_tlb_range() flushes the whole tlb. Flushing the whole
tlb comes with a greater cost than flushing a single entry so we should
flush single entries up to a certain threshold so that:
threshold * cost of flushing a single entry < cost of flushing the whole
tlb.
Co-developed-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231030133027.19542-4-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

flush_tlb_range() uses a fixed stride of PAGE_SIZE and in its current form,
when a hugetlb mapping needs to be flushed, flush_tlb_range() flushes the
whole tlb: so set a stride of the size of the hugetlb mapping in order to
only flush the hugetlb mapping. However, if the hugepage is a NAPOT region,
all PTEs that constitute this mapping must be invalidated, so the stride
size must actually be the size of the PTE.

Note that THPs are directly handled by flush_pmd_tlb_range().
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Link: https://lore.kernel.org/r/20231030133027.19542-3-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

For now, tlb_flush() simply calls flush_tlb_mm() which results in a
flush of the whole TLB. So let's use mmu_gather fields to provide a more
fine-grained flush of the TLB.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Link: https://lore.kernel.org/r/20231030133027.19542-2-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This adds a separate segment for kernel text in /proc/kcore, which has a
different address than the direct linear map.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Link: https://lore.kernel.org/r/mvmh6m758ao.fsf@suse.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Some data were incorrectly annotated with SYM_FUNC_*() instead of
SYM_DATA_*() ones. Use the correct ones.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231024132655.730417-4-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

ENTRY()/END()/WEAK() macros are deprecated and we should make use of the
new SYM_*() macros [1] for better annotation of symbols. Replace the
deprecated ones with the new ones and fix wrong usage of END()/ENDPROC()
to correctly describe the symbols.

[1] https://docs.kernel.org/core-api/asm-annotations.htmlSigned-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231024132655.730417-3-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

For the sake of coherency, use local labels in assembly when
applicable. This also avoid kprobes being confused when applying a
kprobe since the size of function is computed by checking where the
next visible symbol is located. This might end up in computing some
function size to be way shorter than expected and thus failing to apply
kprobes to the specified offset.
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231024132655.730417-2-cleger@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

When flashing loader.bin for K210 using kflash:

    [ERROR] This is an ELF file and cannot be programmed to flash directly: arch/riscv/boot/loader.bin

Before, loader.bin relied on "OBJCOPYFLAGS := -O binary" in the main
RISC-V Makefile to create a boot image with the right format.  With this
removed, the image is now created in the wrong (ELF) format.

Fix this by adding an explicit rule.

Fixes: 505b0295 ("riscv: Remove duplicate objcopy flag")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/1086025809583809538dfecaa899892218f44e7e.1698159066.git.geert+renesas@glider.beSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Alexandre Ghiti <alexghiti@rivosinc.com> says:

This series optimizes the tlb flushes on riscv which used to simply
flush the whole tlb whatever the size of the range to flush or the size
of the stride.

Patch 3 introduces a threshold that is microarchitecture specific and
will very likely be modified by vendors, not sure though which mechanism
we'll use to do that (dt? alternatives? vendor initialization code?).

* b4-shazam-merge:
  riscv: Improve flush_tlb_kernel_range()
  riscv: Make __flush_tlb_range() loop over pte instead of flushing the whole tlb
  riscv: Improve flush_tlb_range() for hugetlb pages
  riscv: Improve tlb_flush()

Link: https://lore.kernel.org/r/20231030133027.19542-1-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This function used to simply flush the whole tlb of all harts, be more
subtile and try to only flush the range.

The problem is that we can only use PAGE_SIZE as stride since we don't know
the size of the underlying mapping and then this function will be improved
only if the size of the region to flush is < threshold * PAGE_SIZE.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231030133027.19542-5-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Currently, when the range to flush covers more than one page (a 4K page or
a hugepage), __flush_tlb_range() flushes the whole tlb. Flushing the whole
tlb comes with a greater cost than flushing a single entry so we should
flush single entries up to a certain threshold so that:
threshold * cost of flushing a single entry < cost of flushing the whole
tlb.
Co-developed-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231030133027.19542-4-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

flush_tlb_range() uses a fixed stride of PAGE_SIZE and in its current form,
when a hugetlb mapping needs to be flushed, flush_tlb_range() flushes the
whole tlb: so set a stride of the size of the hugetlb mapping in order to
only flush the hugetlb mapping. However, if the hugepage is a NAPOT region,
all PTEs that constitute this mapping must be invalidated, so the stride
size must actually be the size of the PTE.

Note that THPs are directly handled by flush_pmd_tlb_range().
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Link: https://lore.kernel.org/r/20231030133027.19542-3-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

For now, tlb_flush() simply calls flush_tlb_mm() which results in a
flush of the whole TLB. So let's use mmu_gather fields to provide a more
fine-grained flush of the TLB.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> # On RZ/Five SMARC
Link: https://lore.kernel.org/r/20231030133027.19542-2-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Update T-Head memory type definitions according to C910 doc [1]
For NC and IO, SH property isn't configurable, hardcoded as SH,
so set SH for NOCACHE and IO.

And also set bit[61](Bufferable) for NOCACHE according to the
table 6.1 in the doc [1].

Link: https://github.com/T-head-Semi/openc910 [1]
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Tested-by: Drew Fustini <dfustini@baylibre.com>
Link: https://lore.kernel.org/r/20230912072510.2510-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Jisheng Zhang <jszhang@kernel.org> says:

This series renews one of my last year RFC patch[1], tries to improve
the vdso layout a bit.

patch1 removes useless symbols
patch2 merges .data section of vdso into .rodata because they are
readonly
patch3 is the real renew patch, it removes hardcoded 0x800 .text start
addr. But I rewrite the commit msg per Andrew's suggestions and move
move .note, .eh_frame_hdr, and .eh_frame between .rodata and .text to
keep the actual code well away from the non-instruction data.

* b4-shazam-merge:
  riscv: vdso.lds.S: remove hardcoded 0x800 .text start addr
  riscv: vdso.lds.S: merge .data section into .rodata section
  riscv: vdso.lds.S: drop __alt_start and __alt_end symbols

Link: https://lore.kernel.org/linux-riscv/20221123161805.1579-1-jszhang@kernel.org/ [1]
Link: https://lore.kernel.org/r/20230912072015.2424-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

I believe the hardcoded 0x800 and related comments come from the long
history VDSO_TEXT_OFFSET in x86 vdso code, but commit 5b930493
("x86 vDSO: generate vdso-syms.lds") and commit f6b46ebf ("x86
vDSO: new layout") removes the comment and hard coding for x86.

Similar as x86 and other arch, riscv doesn't need the rigid layout
using VDSO_TEXT_OFFSET since it "no longer matters to the kernel".
so we could remove the hard coding now, and removing it brings a
small vdso.so and aligns with other architectures.

Also, having enough separation between data and text is important for
I-cache, so similar as x86, move .note, .eh_frame_hdr, and .eh_frame
between .rodata and .text.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Link: https://lore.kernel.org/r/20230912072015.2424-4-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

The .data section doesn't need to be separate from .rodata section,
they are both readonly.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Link: https://lore.kernel.org/r/20230912072015.2424-3-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

These two symbols are not used, remove them.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Link: https://lore.kernel.org/r/20230912072015.2424-2-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Add userland instruction dump and rename dump_kernel_instr()
to dump_instr().

An example:
[    0.822439] Freeing unused kernel image (initmem) memory: 6916K
[    0.823817] Run /init as init process
[    0.839411] init[1]: unhandled signal 4 code 0x1 at 0x000000000005be18 in bb[10000+5fb000]
[    0.840751] CPU: 0 PID: 1 Comm: init Not tainted 5.14.0-rc4-00049-gbd644290aa72-dirty #187
[    0.841373] Hardware name:  , BIOS
[    0.841743] epc : 000000000005be18 ra : 0000000000079e74 sp : 0000003fffcafda0
[    0.842271]  gp : ffffffff816e9dc8 tp : 0000000000000000 t0 : 0000000000000000
[    0.842947]  t1 : 0000003fffc9fdf0 t2 : 0000000000000000 s0 : 0000000000000000
[    0.843434]  s1 : 0000000000000000 a0 : 0000003fffca0190 a1 : 0000003fffcafe18
[    0.843891]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[    0.844357]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000
[    0.844803]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
[    0.845253]  s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000
[    0.845722]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000
[    0.846180]  s11: 0000000000d144e0 t3 : 0000000000000000 t4 : 0000000000000000
[    0.846616]  t5 : 0000000000000000 t6 : 0000000000000000
[    0.847204] status: 0000000200000020 badaddr: 00000000f0028053 cause: 0000000000000002
[    0.848219] Code: f06f ff5f 3823 fa11 0113 fb01 2e23 0201 0293 0000 (8053) f002
[    0.851016] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230912021349.28302-1-cuiyunhui@bytedance.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Instructions can write to x0, so we should simulate these instructions
normally.

Currently, the kernel hangs if an instruction who writes to x0 is
simulated.

Fixes: c22b0bcb ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao <namcaov@gmail.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230829182500.61875-1-namcaov@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

uprobes expects is_trap_insn() to return true for any trap instructions,
not just the one used for installing uprobe. The current default
implementation only returns true for 16-bit c.ebreak if C extension is
enabled. This can confuse uprobes if a 32-bit ebreak generates a trap
exception from userspace: uprobes asks is_trap_insn() who says there is no
trap, so uprobes assume a probe was there before but has been removed, and
return to the trap instruction. This causes an infinite loop of entering
and exiting trap handler.

Instead of using the default implementation, implement this function
speficially for riscv with checks for both ebreak and c.ebreak.

Fixes: 74784081 ("riscv: Add uprobes supported")
Signed-off-by: Nam Cao <namcaov@gmail.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230829083614.117748-1-namcaov@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Yu Chien Peter Lin <peterlin@andestech.com> says:

This patchset enhances PTDUMP by providing additional information
from pagetable entries.

The first patch fixes the RSW field, while the second and third
patches introduce the PBMT and NAPOT fields, respectively, for
RV64 systems.

* b4-shazam-merge:
  riscv: Introduce NAPOT field to PTDUMP
  riscv: Introduce PBMT field to PTDUMP
  riscv: Improve PTDUMP to show RSW with non-zero value

Link: https://lore.kernel.org/r/20230921025022.3989723-1-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This patch introduces the NAPOT field to PTDUMP, allowing it
to display the letter "N" for pages that have the 63rd bit set.
Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230921025022.3989723-4-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

This patch introduces the PBMT field to the PTDUMP, so it can
display the memory attributes for NC or IO.
Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230921025022.3989723-3-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

RSW field can be used to encode 2 bits of software
defined information. Currently, PTDUMP only prints
"RSW" when its value is 1 or 3.

To fix this issue and improve the debugging experience
with PTDUMP, we redefine _PAGE_SPECIAL to its original
value and use _PAGE_SOFT as the RSW mask, allow it to
print the RSW with any non-zero value.

This patch also removes the val from the struct prot_bits
as it is no longer needed.
Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230921025022.3989723-2-peterlin@andestech.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

The CMO op macros initially used lower case, as the original iteration
of the ALT_CMO_OP alternative stringified the first parameter to
finalise the assembly for the standard variant.
As a knock-on, the T-Head versions of these CMOs had to use mixed case
defines. Commit dd23e953 ("RISC-V: replace cbom instructions with
an insn-def") removed the asm construction with stringify, replacing it
an insn-def macro, rending the lower-case surplus to requirements.
As far as I can tell from a brief check, CBO_zero does not see similar
use and didn't require the mixed case define in the first place.
Replace the lower case characters now for consistency with other
insn-def macros in the standard and T-Head forms, and adjust the
callsites.
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230915-aloe-dollar-994937477776@spudSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

If misaligned_access_speed percpu var isn't so called "HWPROBE
MISALIGNED UNKNOWN", it means the probe has happened(this is possible
for example, hotplug off then hotplug on one cpu), and the percpu var
has been set, don't probe again in this case.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Fixes: 584ea656 ("RISC-V: Probe for unaligned access speed")
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230912154040.3306-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

If these config not set, mmc can't run for jh7110, rootfs can't
be found when using SD card. So set CONFIG_MMC_DW=y like arm64
defconfig, and set CONFIG_MMC_DW_STARFIVE=y for starfive. Then
starfive vf2 board can start SD card rootfs with mainline defconfig
and dtb.
Signed-off-by: Jinyu Tang <tangjinyu@tinylab.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230912133128.5247-1-tangjinyu@tinylab.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>

In the current riscv implementation, blocking syscalls like read() may
not correctly restart after being interrupted by ptrace. This problem
arises when the syscall restart process in arch_do_signal_or_restart()
is bypassed due to changes to the regs->cause register, such as an
ebreak instruction.

Steps to reproduce:
1. Interrupt the tracee process with PTRACE_SEIZE & PTRACE_INTERRUPT.
2. Backup original registers and instruction at new_pc.
3. Change pc to new_pc, and inject an instruction (like ebreak) to this
   address.
4. Resume with PTRACE_CONT and wait for the process to stop again after
   executing ebreak.
5. Restore original registers and instructions, and detach from the
   tracee process.
6. Now the read() syscall in tracee will return -1 with errno set to
   ERESTARTSYS.

Specifically, during an interrupt, the regs->cause changes from
EXC_SYSCALL to EXC_BREAKPOINT due to the injected ebreak, which is
inaccessible via ptrace so we cannot restore it. This alteration breaks
the syscall restart condition and ends the read() syscall with an
ERESTARTSYS error. According to include/linux/errno.h, it should never
be seen by user programs. X86 can avoid this issue as it checks the
syscall condition using a register (orig_ax) exposed to user space.
Arm64 handles syscall restart before calling get_signal, where it could
be paused and inspected by ptrace/debugger.

This patch adjusts the riscv implementation to arm64 style, which also
checks syscall using a kernel register (syscallno). It ensures the
syscall restart process is not bypassed when changes to the cause
register occur, providing more consistent behavior across various
architectures.

For a simplified reproduction program, feel free to visit:
https://github.com/ancientmodern/riscv-ptrace-bug-demo.
Signed-off-by: Haorong Lu <ancientmodern4@gmail.com>
Link: https://lore.kernel.org/r/20230803224458.4156006-1-ancientmodern4@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>