1015 Commits

Author SHA1 Message Date
Jisheng Zhang
26b6f927bb riscv: vdso: fix section overlapping under some conditions
commit 74f6bb55c834da6d4bac24f44868202743189b2b upstream.

lkp reported a build error, I tried the config and can reproduce
build error as below:

  VDSOLD  arch/riscv/kernel/vdso/vdso.so.dbg
ld.lld: error: section .note file range overlaps with .text
>>> .note range is [0x7C8, 0x803]
>>> .text range is [0x800, 0x1993]

ld.lld: error: section .text file range overlaps with .dynamic
>>> .text range is [0x800, 0x1993]
>>> .dynamic range is [0x808, 0x937]

ld.lld: error: section .note virtual address range overlaps with .text
>>> .note range is [0x7C8, 0x803]
>>> .text range is [0x800, 0x1993]

Fix it by setting DISABLE_BRANCH_PROFILING which will disable branch
tracing for vdso, thus avoid useless _ftrace_annotated_branch section
and _ftrace_branch section. Although we can also fix it by removing
the hardcoded .text begin address, but I think that's another story
and should be put into another patch.

Link: https://lore.kernel.org/lkml/202210122123.Cc4FPShJ-lkp@intel.com/#r
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20221102170254.1925-1-jszhang@kernel.org
Fixes: ad5d1122b82f ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-08 11:23:57 +01:00
Nathan Chancellor
c0bb600f07 RISC-V: vdso: Do not add missing symbols to version section in linker script
[ Upstream commit fcae44fd36d052e956e69a64642fc03820968d78 ]

Recently, ld.lld moved from '--undefined-version' to
'--no-undefined-version' as the default, which breaks the compat vDSO
build:

  ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_gettimeofday' failed: symbol not defined
  ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_gettime' failed: symbol not defined
  ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_getres' failed: symbol not defined

These symbols are not present in the compat vDSO or the regular vDSO for
32-bit but they are unconditionally included in the version section of
the linker script, which is prohibited with '--no-undefined-version'.

Fix this issue by only including the symbols that are actually exported
in the version section of the linker script.

Link: https://github.com/ClangBuiltLinux/linux/issues/1756
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221108171324.3377226-1-nathan@kernel.org/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-02 17:39:58 +01:00
Emil Renner Berthing
1c9eb641d1 riscv: dts: sifive unleashed: Add PWM controlled LEDs
[ Upstream commit 8bc8824d30193eb7755043d5bb65fa7f0d11a595 ]

This adds the 4 PWM controlled green LEDs to the HiFive Unleashed device
tree. The schematic doesn't specify any special function for the LEDs,
so they're added here without any default triggers and named d1, d2, d3
and d4 just like in the schematic.

Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221012110928.352910-1-emil.renner.berthing@canonical.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-02 17:39:57 +01:00
Conor Dooley
94ab8f88fe riscv: fix reserved memory setup
[ Upstream commit 50e63dd8ed92045eb70a72d7ec725488320fb68b ]

Currently, RISC-V sets up reserved memory using the "early" copy of the
device tree. As a result, when trying to get a reserved memory region
using of_reserved_mem_lookup(), the pointer to reserved memory regions
is using the early, pre-virtual-memory address which causes a kernel
panic when trying to use the buffer's name:

 Unable to handle kernel paging request at virtual address 00000000401c31ac
 Oops [#1]
 Modules linked in:
 CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc1-00001-g0d9d6953d834 #1
 Hardware name: Microchip PolarFire-SoC Icicle Kit (DT)
 epc : string+0x4a/0xea
  ra : vsnprintf+0x1e4/0x336
 epc : ffffffff80335ea0 ra : ffffffff80338936 sp : ffffffff81203be0
  gp : ffffffff812e0a98 tp : ffffffff8120de40 t0 : 0000000000000000
  t1 : ffffffff81203e28 t2 : 7265736572203a46 s0 : ffffffff81203c20
  s1 : ffffffff81203e28 a0 : ffffffff81203d22 a1 : 0000000000000000
  a2 : ffffffff81203d08 a3 : 0000000081203d21 a4 : ffffffffffffffff
  a5 : 00000000401c31ac a6 : ffff0a00ffffff04 a7 : ffffffffffffffff
  s2 : ffffffff81203d08 s3 : ffffffff81203d00 s4 : 0000000000000008
  s5 : ffffffff000000ff s6 : 0000000000ffffff s7 : 00000000ffffff00
  s8 : ffffffff80d9821a s9 : ffffffff81203d22 s10: 0000000000000002
  s11: ffffffff80d9821c t3 : ffffffff812f3617 t4 : ffffffff812f3617
  t5 : ffffffff812f3618 t6 : ffffffff81203d08
 status: 0000000200000100 badaddr: 00000000401c31ac cause: 000000000000000d
 [<ffffffff80338936>] vsnprintf+0x1e4/0x336
 [<ffffffff80055ae2>] vprintk_store+0xf6/0x344
 [<ffffffff80055d86>] vprintk_emit+0x56/0x192
 [<ffffffff80055ed8>] vprintk_default+0x16/0x1e
 [<ffffffff800563d2>] vprintk+0x72/0x80
 [<ffffffff806813b2>] _printk+0x36/0x50
 [<ffffffff8068af48>] print_reserved_mem+0x1c/0x24
 [<ffffffff808057ec>] paging_init+0x528/0x5bc
 [<ffffffff808031ae>] setup_arch+0xd0/0x592
 [<ffffffff8080070e>] start_kernel+0x82/0x73c

early_init_fdt_scan_reserved_mem() takes no arguments as it operates on
initial_boot_params, which is populated by early_init_dt_verify(). On
RISC-V, early_init_dt_verify() is called twice. Once, directly, in
setup_arch() if CONFIG_BUILTIN_DTB is not enabled and once indirectly,
very early in the boot process, by parse_dtb() when it calls
early_init_dt_scan_nodes().

This first call uses dtb_early_va to set initial_boot_params, which is
not usable later in the boot process when
early_init_fdt_scan_reserved_mem() is called. On arm64 for example, the
corresponding call to early_init_dt_scan_nodes() uses fixmap addresses
and doesn't suffer the same fate.

Move early_init_fdt_scan_reserved_mem() further along the boot sequence,
after the direct call to early_init_dt_verify() in setup_arch() so that
the names use the correct virtual memory addresses. The above supposed
that CONFIG_BUILTIN_DTB was not set, but should work equally in the case
where it is - unflatted_and_copy_device_tree() also updates
initial_boot_params.

Reported-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Reported-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/linux-riscv/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/r/20221107151524.3941467-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:14 +01:00
Atish Patra
0cf9cb0614 riscv: Separate memory init from paging init
[ Upstream commit cbd34f4bb37d62d8a027f54205bff07e73340da4 ]

Currently, we perform some memory init functions in paging init. But,
that will be an issue for NUMA support where DT needs to be flattened
before numa initialization and memblock_present can only be called
after numa initialization.

Move memory initialization related functions to a separate function.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Stable-dep-of: 50e63dd8ed92 ("riscv: fix reserved memory setup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:14 +01:00
Kefeng Wang
d7716240bc riscv: Enable CMA support
[ Upstream commit da815582cf4594e96defa1cddb72cd00b1e7aac5 ]

riscv has selected HAVE_DMA_CONTIGUOUS, but doesn't call
dma_contiguous_reserve().  This calls dma_contiguous_reserve(), which
enables CMA.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Stable-dep-of: 50e63dd8ed92 ("riscv: fix reserved memory setup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:14 +01:00
Jisheng Zhang
ecf78af514 riscv: vdso: fix build with llvm
[ Upstream commit 50f4dd657a0fcf90aa8da8dc2794a8100ff4c37c ]

Even after commit 89fd4a1df829 ("riscv: jump_label: mark arguments as
const to satisfy asm constraints"), building with CC_OPTIMIZE_FOR_SIZE
+ LLVM=1 can reproduce below build error:

  CC      arch/riscv/kernel/vdso/vgettimeofday.o
In file included from <built-in>:4:
In file included from lib/vdso/gettimeofday.c:5:
In file included from include/vdso/datapage.h:17:
In file included from include/vdso/processor.h:10:
In file included from arch/riscv/include/asm/vdso/processor.h:7:
In file included from include/linux/jump_label.h:112:
arch/riscv/include/asm/jump_label.h:42:3: error:
invalid operand for inline asm constraint 'i'
                "       .option push                            \n\t"
                ^
1 error generated.

I think the problem is when "-Os" is passed as CFLAGS, it's removed by
"CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os" which is
introduced in commit e05d57dcb8c7 ("riscv: Fixup __vdso_gettimeofday
broke dynamic ftrace"), thus no optimization at all for vgettimeofday.c
arm64 does remove "-Os" as well, but it forces "-O2" after removing
"-Os".

I compared the generated vgettimeofday.o with "-O2" and "-Os",
I think no big performance difference. So let's tell the kbuild not
to remove "-Os" rather than follow arm64 style.

vdso related performance can be improved a lot when building kernel with
CC_OPTIMIZE_FOR_SIZE after this commit, ("-Os" VS no optimization)

Fixes: e05d57dcb8c7 ("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221031182943.2453-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:14 +01:00
Jisheng Zhang
e56d18a976 riscv: process: fix kernel info leakage
[ Upstream commit 6510c78490c490a6636e48b61eeaa6fb65981f4b ]

thread_struct's s[12] may contain random kernel memory content, which
may be finally leaked to userspace. This is a security hole. Fix it
by clearing the s[12] array in thread_struct when fork.

As for kthread case, it's better to clear the s[12] array as well.

Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20221029113450.4027-1-jszhang@kernel.org
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/CAJF2gTSdVyAaM12T%2B7kXAdRPGS4VyuO08X1c7paE-n4Fr8OtRA@mail.gmail.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-11-16 09:57:14 +01:00
Conor Dooley
79c3482fbe riscv: topology: fix default topology reporting
commit fbd92809997a391f28075f1c8b5ee314c225557c upstream.

RISC-V has no sane defaults to fall back on where there is no cpu-map
in the devicetree.
Without sane defaults, the package, core and thread IDs are all set to
-1. This causes user-visible inaccuracies for tools like hwloc/lstopo
which rely on the sysfs cpu topology files to detect a system's
topology.

On a PolarFire SoC, which should have 4 harts with a thread each,
lstopo currently reports:

Machine (793MB total)
  Package L#0
    NUMANode L#0 (P#0 793MB)
    Core L#0
      L1d L#0 (32KB) + L1i L#0 (32KB) + PU L#0 (P#0)
      L1d L#1 (32KB) + L1i L#1 (32KB) + PU L#1 (P#1)
      L1d L#2 (32KB) + L1i L#2 (32KB) + PU L#2 (P#2)
      L1d L#3 (32KB) + L1i L#3 (32KB) + PU L#3 (P#3)

Adding calls to store_cpu_topology() in {boot,smp} hart bringup code
results in the correct topolgy being reported:

Machine (793MB total)
  Package L#0
    NUMANode L#0 (P#0 793MB)
    L1d L#0 (32KB) + L1i L#0 (32KB) + Core L#0 + PU L#0 (P#0)
    L1d L#1 (32KB) + L1i L#1 (32KB) + Core L#1 + PU L#1 (P#1)
    L1d L#2 (32KB) + L1i L#2 (32KB) + Core L#2 + PU L#2 (P#2)
    L1d L#3 (32KB) + L1i L#3 (32KB) + Core L#3 + PU L#3 (P#3)

CC: stable@vger.kernel.org # 456797da792f: arm64: topology: move store_cpu_topology() to shared code
Fixes: 03f11f03dbfe ("RISC-V: Parse cpu topology during boot.")
Reported-by: Brice Goglin <Brice.Goglin@inria.fr>
Link: https://github.com/open-mpi/hwloc/issues/536
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-30 09:41:19 +01:00
Wenting Zhang
86e995f964 riscv: always honor the CONFIG_CMDLINE_FORCE when parsing dtb
[ Upstream commit 10f6913c548b32ecb73801a16b120e761c6957ea ]

When CONFIG_CMDLINE_FORCE is enabled, cmdline provided by
CONFIG_CMDLINE are always used. This allows CONFIG_CMDLINE to be
used regardless of the result of device tree scanning.

This especially fixes the case where a device tree without the
chosen node is supplied to the kernel. In such cases,
early_init_dt_scan would return true. But inside
early_init_dt_scan_chosen, the cmdline won't be updated as there
is no chosen node in the device tree. As a result, CONFIG_CMDLINE
is not copied into boot_command_line even if CONFIG_CMDLINE_FORCE
is enabled. This commit allows properly update boot_command_line
in this situation.

Fixes: 8fd6e05c7463 ("arch: riscv: support kernel command line forcing when no DTB passed")
Signed-off-by: Wenting Zhang <zephray@outlook.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/PSBPR04MB399135DFC54928AB958D0638B1829@PSBPR04MB3991.apcprd04.prod.outlook.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:18 +01:00
Kefeng Wang
0e4c06ae7c riscv: Add machine name to kernel boot log and stack dump output
[ Upstream commit 46ad48e8a28da7cc37a16c7e7fc632ecf906e4bf ]

Add the machine name to kernel boot-up log, and install
the machine name to stack dump for DT boot mode.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Stable-dep-of: 10f6913c548b ("riscv: always honor the CONFIG_CMDLINE_FORCE when parsing dtb")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-30 09:41:18 +01:00
Fangrui Song
1a053f597f riscv: Pass -mno-relax only on lld < 15.0.0
commit 3cebf80e9a0d3adcb174053be32c88a640b3344b upstream.

lld since llvm:6611d58f5bbc ("[ELF] Relax R_RISCV_ALIGN"), which will be
included in the 15.0.0 release, has implemented some RISC-V linker
relaxation.  -mno-relax is no longer needed in
KBUILD_CFLAGS/KBUILD_AFLAGS to suppress R_RISCV_ALIGN which older lld
can not handle:

    ld.lld: error: capability.c:(.fixup+0x0): relocation R_RISCV_ALIGN
    requires unimplemented linker relaxation; recompile with -mno-relax
    but the .o is already compiled with -mno-relax

Signed-off-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20220710071117.446112-1-maskray@google.com/
Link: https://lore.kernel.org/r/20220918092933.19943-1-palmer@rivosinc.com
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:10 +02:00
Andrew Bresticker
d15dca1d46 riscv: Make VM_WRITE imply VM_READ
commit 7ab72c597356be1e7f0f3d856e54ce78527f43c8 upstream.

RISC-V does not presently have write-only mappings as that PTE bit pattern
is considered reserved in the privileged spec, so allow handling of read
faults in VMAs that have VM_WRITE without VM_READ in order to be consistent
with other architectures that have similar limitations.

Fixes: 2139619bcad7 ("riscv: mmap with PROT_WRITE but no PROT_READ is invalid")
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Andrew Bresticker <abrestic@rivosinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220915193702.2201018-2-abrestic@rivosinc.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:10 +02:00
Andrew Bresticker
d8c6f9b2e1 riscv: Allow PROT_WRITE-only mmap()
commit 9e2e6042a7ec6504fe8e366717afa2f40cf16488 upstream.

Commit 2139619bcad7 ("riscv: mmap with PROT_WRITE but no PROT_READ is
invalid") made mmap() return EINVAL if PROT_WRITE was set wihtout
PROT_READ with the justification that a write-only PTE is considered a
reserved PTE permission bit pattern in the privileged spec. This check
is unnecessary since we let VM_WRITE imply VM_READ on RISC-V, and it is
inconsistent with other architectures that don't support write-only PTEs,
creating a potential software portability issue. Just remove the check
altogether and let PROT_WRITE imply PROT_READ as is the case on other
architectures.

Note that this also allows PROT_WRITE|PROT_EXEC mappings which were
disallowed prior to the aforementioned commit; PROT_READ is implied in
such mappings as well.

Fixes: 2139619bcad7 ("riscv: mmap with PROT_WRITE but no PROT_READ is invalid")
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Andrew Bresticker <abrestic@rivosinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220915193702.2201018-3-abrestic@rivosinc.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:10 +02:00
Maciej W. Rozycki
2ce9fab94b RISC-V: Make port I/O string accessors actually work
commit 9cc205e3c17d5716da7ebb7fa0c985555e95d009 upstream.

Fix port I/O string accessors such as `insb', `outsb', etc. which use
the physical PCI port I/O address rather than the corresponding memory
mapping to get at the requested location, which in turn breaks at least
accesses made by our parport driver to a PCIe parallel port such as:

PCI parallel port detected: 1415:c118, I/O at 0x1000(0x1008), IRQ 20
parport0: PC-style at 0x1000 (0x1008), irq 20, using FIFO [PCSPP,TRISTATE,COMPAT,EPP,ECP]

causing a memory access fault:

Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000001008
Oops [#1]
Modules linked in:
CPU: 1 PID: 350 Comm: cat Not tainted 6.0.0-rc2-00283-g10d4879f9ef0-dirty #23
Hardware name: SiFive HiFive Unmatched A00 (DT)
epc : parport_pc_fifo_write_block_pio+0x266/0x416
 ra : parport_pc_fifo_write_block_pio+0xb4/0x416
epc : ffffffff80542c3e ra : ffffffff80542a8c sp : ffffffd88899fc60
 gp : ffffffff80fa2700 tp : ffffffd882b1e900 t0 : ffffffd883d0b000
 t1 : ffffffffff000002 t2 : 4646393043330a38 s0 : ffffffd88899fcf0
 s1 : 0000000000001000 a0 : 0000000000000010 a1 : 0000000000000000
 a2 : ffffffd883d0a010 a3 : 0000000000000023 a4 : 00000000ffff8fbb
 a5 : ffffffd883d0a001 a6 : 0000000100000000 a7 : ffffffc800000000
 s2 : ffffffffff000002 s3 : ffffffff80d28880 s4 : ffffffff80fa1f50
 s5 : 0000000000001008 s6 : 0000000000000008 s7 : ffffffd883d0a000
 s8 : 0004000000000000 s9 : ffffffff80dc1d80 s10: ffffffd8807e4000
 s11: 0000000000000000 t3 : 00000000000000ff t4 : 393044410a303930
 t5 : 0000000000001000 t6 : 0000000000040000
status: 0000000200000120 badaddr: 0000000000001008 cause: 000000000000000f
[<ffffffff80543212>] parport_pc_compat_write_block_pio+0xfe/0x200
[<ffffffff8053bbc0>] parport_write+0x46/0xf8
[<ffffffff8050530e>] lp_write+0x158/0x2d2
[<ffffffff80185716>] vfs_write+0x8e/0x2c2
[<ffffffff80185a74>] ksys_write+0x52/0xc2
[<ffffffff80185af2>] sys_write+0xe/0x16
[<ffffffff80003770>] ret_from_syscall+0x0/0x2
---[ end trace 0000000000000000 ]---

For simplicity address the problem by adding PCI_IOBASE to the physical
address requested in the respective wrapper macros only, observing that
the raw accessors such as `__insb', `__outsb', etc. are not supposed to
be used other than by said macros.  Remove the cast to `long' that is no
longer needed on `addr' now that it is used as an offset from PCI_IOBASE
and add parentheses around `addr' needed for predictable evaluation in
macro expansion.  No need to make said adjustments in separate changes
given that current code is gravely broken and does not ever work.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: fab957c11efe2 ("RISC-V: Atomic and Locking Code")
Cc: stable@vger.kernel.org # v4.15+
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2209220223080.29493@angie.orcam.me.uk
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-26 13:25:09 +02:00
Al Viro
12fda27a41 riscv: fix a nasty sigreturn bug...
commit 762df359aa5849e010ef04c3ed79d57588ce17d9 upstream.

riscv has an equivalent of arm bug fixed by 653d48b22166 ("arm: fix
really nasty sigreturn bug"); if signal gets caught by an interrupt that
hits when we have the right value in a0 (-513), *and* another signal
gets delivered upon sigreturn() (e.g. included into the blocked mask for
the first signal and posted while the handler had been running), the
syscall restart logics will see regs->cause equal to EXC_SYSCALL (we are
in a syscall, after all) and a0 already restored to its original value
(-513, which happens to be -ERESTARTNOINTR) and assume that we need to
apply the usual syscall restart logics.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/YxJEiSq%2FCGaL6Gm9@ZenIV/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28 11:10:27 +02:00
Steven Price
47a73e5e6b mm: pagewalk: Fix race between unmap and page walker
[ Upstream commit 8782fb61cc848364e1e1599d76d3c9dd58a1cc06 ]

The mmap lock protects the page walker from changes to the page tables
during the walk.  However a read lock is insufficient to protect those
areas which don't have a VMA as munmap() detaches the VMAs before
downgrading to a read lock and actually tearing down PTEs/page tables.

For users of walk_page_range() the solution is to simply call pte_hole()
immediately without checking the actual page tables when a VMA is not
present. We now never call __walk_page_range() without a valid vma.

For walk_page_range_novma() the locking requirements are tightened to
require the mmap write lock to be taken, and then walking the pgd
directly with 'no_vma' set.

This in turn means that all page walkers either have a valid vma, or
it's that special 'novma' case for page table debugging.  As a result,
all the odd '(!walk->vma && !walk->no_vma)' tests can be removed.

Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-08 11:11:38 +02:00
Xianting Tian
399d245775 RISC-V: Add fast call path of crash_kexec()
[ Upstream commit 3f1901110a89b0e2e13adb2ac8d1a7102879ea98 ]

Currently, almost all archs (x86, arm64, mips...) support fast call
of crash_kexec() when "regs && kexec_should_crash()" is true. But
RISC-V not, it can only enter crash system via panic(). However panic()
doesn't pass the regs of the real accident scene to crash_kexec(),
it caused we can't get accurate backtrace via gdb,
	$ riscv64-linux-gnu-gdb vmlinux vmcore
	Reading symbols from vmlinux...
	[New LWP 95]
	#0  console_unlock () at kernel/printk/printk.c:2557
	2557                    if (do_cond_resched)
	(gdb) bt
	#0  console_unlock () at kernel/printk/printk.c:2557
	#1  0x0000000000000000 in ?? ()

With the patch we can get the accurate backtrace,
	$ riscv64-linux-gnu-gdb vmlinux vmcore
	Reading symbols from vmlinux...
	[New LWP 95]
	#0  0xffffffe00063a4e0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81
	81             *(int *)p = 0xdead;
	(gdb)
	(gdb) bt
	#0  0xffffffe00064d5c0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81
	#1  0x0000000000000000 in ?? ()

Test code to produce NULL address dereference in test_crash.c,
	void *p = NULL;
	*(int *)p = 0xdead;

Reviewed-by: Guo Ren <guoren@kernel.org>
Tested-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220606082308.2883458-1-xianting.tian@linux.alibaba.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:38:19 +02:00
Celeste Liu
d881c98d0a riscv: mmap with PROT_WRITE but no PROT_READ is invalid
[ Upstream commit 2139619bcad7ac44cc8f6f749089120594056613 ]

As mentioned in Table 4.5 in RISC-V spec Volume 2 Section 4.3, write
but not read is "Reserved for future use.". For now, they are not valid.
In the current code, -wx is marked as invalid, but -w- is not marked
as invalid.
This patch refines that judgment.

Reported-by: xctan <xc-tan@outlook.com>
Co-developed-by: dram <dramforever@live.com>
Signed-off-by: dram <dramforever@live.com>
Co-developed-by: Ruizhe Pan <c141028@gmail.com>
Signed-off-by: Ruizhe Pan <c141028@gmail.com>
Signed-off-by: Celeste Liu <coelacanthus@outlook.com>
Link: https://lore.kernel.org/r/PH7PR14MB559464DBDD310E755F5B21E8CEDC9@PH7PR14MB5594.namprd14.prod.outlook.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-25 11:38:19 +02:00
Dimitri John Ledkov
3ff605513f riscv: set default pm_power_off to NULL
commit f2928e224d85e7cc139009ab17cefdfec2df5d11 upstream.

Set pm_power_off to NULL like on all other architectures, check if it
is set in machine_halt() and machine_power_off() and fallback to
default_power_off if no other power driver got registered.

This brings riscv architecture inline with all other architectures,
and allows to reuse exiting power drivers unmodified.

Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
not set), do not set pm_power_off to sbi_shutdown(). There is no
support for SBI v0.3 system reset extension either. This prevents
using gpio_poweroff on SiFive HiFive Unmatched.

Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
node and kernel complied without CONFIG_RISCV_SBI_V01.

BugLink: https://bugs.launchpad.net/bugs/1942806
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Ron Economos <w6rz@comcast.net>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:15:21 +02:00
Ben Dooks
15155fa898 riscv: add as-options for modules with assembly compontents
commit c1f6eff304e4dfa4558b6a8c6b2d26a91db6c998 upstream.

When trying to load modules built for RISC-V which include assembly files
the kernel loader errors with "unexpected relocation type 'R_RISCV_ALIGN'"
due to R_RISCV_ALIGN relocations being generated by the assembler.

The R_RISCV_ALIGN relocations can be removed at the expense of code space
by adding -mno-relax to gcc and as.  In commit 7a8e7da42250138
("RISC-V: Fixes to module loading") -mno-relax is added to the build
variable KBUILD_CFLAGS_MODULE. See [1] for more info.

The issue is that when kbuild builds a .S file, it invokes gcc with
the -mno-relax flag, but this is not being passed through to the
assembler. Adding -Wa,-mno-relax to KBUILD_AFLAGS_MODULE ensures that
the assembler is invoked correctly. This may have now been fixed in
gcc[2] and this addition should not stop newer gcc and as from working.

[1] https://github.com/riscv/riscv-elf-psabi-doc/issues/183
[2] 3b0a7d624e

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Link: https://lore.kernel.org/r/20220529152200.609809-1-ben.dooks@codethink.co.uk
Fixes: ab1ef68e5401 ("RISC-V: Add sections of PLT and GOT for kernel module")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29 17:19:06 +02:00
Heinrich Schuchardt
b97550e380 riscv: read-only pages should not be writable
[ Upstream commit 630f972d76d6460235e84e1aa034ee06f9c8c3a9 ]

If EFI pages are marked as read-only,
we should remove the _PAGE_WRITE flag.

The current code overwrites an unused value.

Fixes: b91540d52a08b ("RISC-V: Add EFI runtime services")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Link: https://lore.kernel.org/r/20220528014132.91052-1-heinrich.schuchardt@canonical.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:32:36 +02:00
Samuel Holland
d2f3acde3d riscv: Fix irq_work when SMP is disabled
commit 2273272823db6f67d57761df8116ae32e7f05bed upstream.

irq_work is triggered via an IPI, but the IPI infrastructure is not
included in uniprocessor kernels. As a result, irq_work never runs.
Fall back to the tick-based irq_work implementation on uniprocessor
configurations.

Fixes: 298447928bb1 ("riscv: Support irq_work via self IPIs")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20220430030025.58405-1-samuel@sholland.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:20:48 +02:00
Alexandre Ghiti
4a5c7a61ff riscv: Initialize thread pointer before calling C functions
commit 35d33c76d68dfacc330a8eb477b51cc647c5a847 upstream.

Because of the stack canary feature that reads from the current task
structure the stack canary value, the thread pointer register "tp" must
be set before calling any C function from head.S: by chance, setup_vm
and all the functions that it calls does not seem to be part of the
functions where the canary check is done, but in the following commits,
some functions will.

Fixes: f2c9699f65557a31 ("riscv: Add STACKPROTECTOR supported")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:20:47 +02:00
Jason A. Donenfeld
714def4497 riscv: use fallback for random_get_entropy() instead of zero
commit 6d01238623faa9425f820353d2066baf6c9dc872 upstream.

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-30 09:33:41 +02:00
Krzysztof Kozlowski
ea8a9cb4a7 riscv: dts: sifive: fu540-c000: align dma node name with dtschema
[ Upstream commit b17410182b6f98191fbf7f42d3b4a78512769d29 ]

Fixes dtbs_check warnings like:

  dma@3000000: $nodename:0: 'dma@3000000' does not match '^dma-controller(@.*)?$'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220407193856.18223-1-krzysztof.kozlowski@linaro.org
Fixes: c5ab54e9945b ("riscv: dts: add support for PDMA device of HiFive Unleashed Rev A00")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-25 09:17:59 +02:00
Guo Ren
8fcce58c59 riscv: patch_text: Fixup last cpu should be master
commit 8ec1442953c66a1d8462cccd8c20b7ba561f5915 upstream.

These patch_text implementations are using stop_machine_cpuslocked
infrastructure with atomic cpu_count. The original idea: When the
master CPU patch_text, the others should wait for it. But current
implementation is using the first CPU as master, which couldn't
guarantee the remaining CPUs are waiting. This patch changes the
last CPU as the master to solve the potential risk.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 043cb41a85de ("riscv: introduce interfaces to patch kernel code")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-09 09:04:59 +02:00
Fangrui Song
785a53373c riscv module: remove (NOLOAD)
commit 60210a3d86dc57ce4a76a366e7841dda746a33f7 upstream.

On ELF, (NOLOAD) sets the section type to SHT_NOBITS[1]. It is conceptually
inappropriate for .plt, .got, and .got.plt sections which are always
SHT_PROGBITS.

In GNU ld, if PLT entries are needed, .plt will be SHT_PROGBITS anyway
and (NOLOAD) will be essentially ignored. In ld.lld, since
https://reviews.llvm.org/D118840 ("[ELF] Support (TYPE=<value>) to
customize the output section type"), ld.lld will report a `section type
mismatch` error (later changed to a warning). Just remove (NOLOAD) to
fix the warning.

[1] https://lld.llvm.org/ELF/linker_script.html As of today, "The
section should be marked as not loadable" on
https://sourceware.org/binutils/docs/ld/Output-Section-Type.html is
outdated for ELF.

Link: https://github.com/ClangBuiltLinux/linux/issues/1597
Fixes: ab1ef68e5401 ("RISC-V: Add sections of PLT and GOT for kernel module")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:40:42 +02:00
Arnd Bergmann
40a5c93a74 uaccess: fix type mismatch warnings from access_ok()
[ Upstream commit 23fc539e81295b14b50c6ccc5baeb4f3d59d822d ]

On some architectures, access_ok() does not do any argument type
checking, so replacing the definition with a generic one causes
a few warnings for harmless issues that were never caught before.

Fix the ones that I found either through my own test builds or
that were reported by the 0-day bot.

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:40:35 +02:00
Dmitry Vyukov
34bc1f69bf riscv: Increase stack size under KASAN
commit b81d591386c3a50b96dddcf663628ea0df0bf2b3 upstream.

KASAN requires more stack space because of compiler instrumentation.
Increase stack size as other arches do.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: syzbot+0600986d88e2d4d7ebb8@syzkaller.appspotmail.com
Fixes: 8ad8b72721d0 ("riscv: Add KASAN support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:39:53 +02:00
Nikita Shubin
24b9b8e95c riscv: Fix fill_callchain return value
commit 2b2b574ac587ec5bd7716a356492a85ab8b0ce9f upstream.

perf_callchain_store return 0 on success, -1 otherwise,
fix fill_callchain to return correct bool value.

Fixes: dbeb90b0c1eb ("riscv: Add perf callchain support")
Signed-off-by: Nikita Shubin <n.shubin@yadro.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:39:52 +02:00
Emil Renner Berthing
1ef5fe3dba riscv: Fix auipc+jalr relocation range checks
commit 0966d385830de3470b7131db8e86c0c5bc9c52dc upstream.

RISC-V can do PC-relative jumps with a 32bit range using the following
two instructions:

	auipc	t0, imm20	; t0 = PC + imm20 * 2^12
	jalr	ra, t0, imm12	; ra = PC + 4, PC = t0 + imm12

Crucially both the 20bit immediate imm20 and the 12bit immediate imm12
are treated as two's-complement signed values. For this reason the
immediates are usually calculated like this:

	imm20 = (offset + 0x800) >> 12
	imm12 = offset & 0xfff

..where offset is the signed offset from the auipc instruction. When
the 11th bit of offset is 0 the addition of 0x800 doesn't change the top
20 bits and imm12 considered positive. When the 11th bit is 1 the carry
of the addition by 0x800 means imm20 is one higher, but since imm12 is
then considered negative the two's complement representation means it
all cancels out nicely.

However, this addition by 0x800 (2^11) means an offset greater than or
equal to 2^31 - 2^11 would overflow so imm20 is considered negative and
result in a backwards jump. Similarly the lower range of offset is also
moved down by 2^11 and hence the true 32bit range is

	[-2^31 - 2^11, 2^31 - 2^11)

Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16 14:16:01 +01:00
Alexandre Ghiti
dd9dd24fd7 riscv: Fix config KASAN && DEBUG_VIRTUAL
commit c648c4bb7d02ceb53ee40172fdc4433b37cee9c6 upstream.

__virt_to_phys function is called very early in the boot process (ie
kasan_early_init) so it should not be instrumented by KASAN otherwise it
bugs.

Fix this by declaring phys_addr.c as non-kasan instrumentable.

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 <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:09:31 +01:00
Alexandre Ghiti
7211aab288 riscv: Fix config KASAN && SPARSEMEM && !SPARSE_VMEMMAP
commit a3d328037846d013bb4c7f3777241e190e4c75e1 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:09:31 +01:00
Changbin Du
9e2dbc31e3 riscv: fix oops caused by irqsoff latency tracer
commit 22e2100b1b07d6f5acc71cc1acb53f680c677d77 upstream.

The trace_hardirqs_{on,off}() require the caller to setup frame pointer
properly. This because these two functions use macro 'CALLER_ADDR1' (aka.
__builtin_return_address(1)) to acquire caller info. If the $fp is used
for other purpose, the code generated this macro (as below) could trigger
memory access fault.

   0xffffffff8011510e <+80>:    ld      a1,-16(s0)
   0xffffffff80115112 <+84>:    ld      s2,-8(a1)  # <-- paging fault here

The oops message during booting if compiled with 'irqoff' tracer enabled:
[    0.039615][    T0] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000f8
[    0.041925][    T0] Oops [#1]
[    0.042063][    T0] Modules linked in:
[    0.042864][    T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.17.0-rc1-00233-g9a20c48d1ed2 #29
[    0.043568][    T0] Hardware name: riscv-virtio,qemu (DT)
[    0.044343][    T0] epc : trace_hardirqs_on+0x56/0xe2
[    0.044601][    T0]  ra : restore_all+0x12/0x6e
[    0.044721][    T0] epc : ffffffff80126a5c ra : ffffffff80003b94 sp : ffffffff81403db0
[    0.044801][    T0]  gp : ffffffff8163acd8 tp : ffffffff81414880 t0 : 0000000000000020
[    0.044882][    T0]  t1 : 0098968000000000 t2 : 0000000000000000 s0 : ffffffff81403de0
[    0.044967][    T0]  s1 : 0000000000000000 a0 : 0000000000000001 a1 : 0000000000000100
[    0.045046][    T0]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[    0.045124][    T0]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000054494d45
[    0.045210][    T0]  s2 : ffffffff80003b94 s3 : ffffffff81a8f1b0 s4 : ffffffff80e27b50
[    0.045289][    T0]  s5 : ffffffff81414880 s6 : ffffffff8160fa00 s7 : 00000000800120e8
[    0.045389][    T0]  s8 : 0000000080013100 s9 : 000000000000007f s10: 0000000000000000
[    0.045474][    T0]  s11: 0000000000000000 t3 : 7fffffffffffffff t4 : 0000000000000000
[    0.045548][    T0]  t5 : 0000000000000000 t6 : ffffffff814aa368
[    0.045620][    T0] status: 0000000200000100 badaddr: 00000000000000f8 cause: 000000000000000d
[    0.046402][    T0] [<ffffffff80003b94>] restore_all+0x12/0x6e

This because the $fp(aka. $s0) register is not used as frame pointer in the
assembly entry code.

	resume_kernel:
		REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
		bnez s0, restore_all
		REG_L s0, TASK_TI_FLAGS(tp)
                andi s0, s0, _TIF_NEED_RESCHED
                beqz s0, restore_all
                call preempt_schedule_irq
                j restore_all

To fix above issue, here we add one extra level wrapper for function
trace_hardirqs_{on,off}() so they can be safely called by low level entry
code.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Fixes: 3c4697982982 ("riscv: Enable LOCKDEP_SUPPORT & fixup TRACE_IRQFLAGS_SUPPORT")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:42:56 +01:00
Aurelien Jarno
3f9843f2f6 riscv: fix build with binutils 2.38
commit 6df2a016c0c8a3d0933ef33dd192ea6606b115e3 upstream.

From version 2.38, binutils default to ISA spec version 20191213. This
means that the csr read/write (csrr*/csrw*) instructions and fence.i
instruction has separated from the `I` extension, become two standalone
extensions: Zicsr and Zifencei. As the kernel uses those instruction,
this causes the following build failure:

  CC      arch/riscv/kernel/vdso/vgettimeofday.o
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h: Assembler messages:
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'
  <<BUILDDIR>>/arch/riscv/include/asm/vdso/gettimeofday.h:71: Error: unrecognized opcode `csrr a5,0xc01'

The fix is to specify those extensions explicitely in -march. However as
older binutils version do not support this, we first need to detect
that.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Tested-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16 12:54:21 +01:00
Sean Christopherson
723acd75a0 perf: Protect perf_guest_cbs with RCU
commit ff083a2d972f56bebfd82409ca62e5dfce950961 upstream.

Protect perf_guest_cbs with RCU to fix multiple possible errors.  Luckily,
all paths that read perf_guest_cbs already require RCU protection, e.g. to
protect the callback chains, so only the direct perf_guest_cbs touchpoints
need to be modified.

Bug #1 is a simple lack of WRITE_ONCE/READ_ONCE behavior to ensure
perf_guest_cbs isn't reloaded between a !NULL check and a dereference.
Fixed via the READ_ONCE() in rcu_dereference().

Bug #2 is that on weakly-ordered architectures, updates to the callbacks
themselves are not guaranteed to be visible before the pointer is made
visible to readers.  Fixed by the smp_store_release() in
rcu_assign_pointer() when the new pointer is non-NULL.

Bug #3 is that, because the callbacks are global, it's possible for
readers to run in parallel with an unregisters, and thus a module
implementing the callbacks can be unloaded while readers are in flight,
resulting in a use-after-free.  Fixed by a synchronize_rcu() call when
unregistering callbacks.

Bug #1 escaped notice because it's extremely unlikely a compiler will
reload perf_guest_cbs in this sequence.  perf_guest_cbs does get reloaded
for future derefs, e.g. for ->is_user_mode(), but the ->is_in_guest()
guard all but guarantees the consumer will win the race, e.g. to nullify
perf_guest_cbs, KVM has to completely exit the guest and teardown down
all VMs before KVM start its module unload / unregister sequence.  This
also makes it all but impossible to encounter bug #3.

Bug #2 has not been a problem because all architectures that register
callbacks are strongly ordered and/or have a static set of callbacks.

But with help, unloading kvm_intel can trigger bug #1 e.g. wrapping
perf_guest_cbs with READ_ONCE in perf_misc_flags() while spamming
kvm_intel module load/unload leads to:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] PREEMPT SMP
  CPU: 6 PID: 1825 Comm: stress Not tainted 5.14.0-rc2+ #459
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:perf_misc_flags+0x1c/0x70
  Call Trace:
   perf_prepare_sample+0x53/0x6b0
   perf_event_output_forward+0x67/0x160
   __perf_event_overflow+0x52/0xf0
   handle_pmi_common+0x207/0x300
   intel_pmu_handle_irq+0xcf/0x410
   perf_event_nmi_handler+0x28/0x50
   nmi_handle+0xc7/0x260
   default_do_nmi+0x6b/0x170
   exc_nmi+0x103/0x130
   asm_exc_nmi+0x76/0xbf

Fixes: 39447b386c84 ("perf: Enhance perf to allow for guest statistic collection from host")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211111020738.2512932-2-seanjc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-20 09:17:50 +01:00
Alexandre Ghiti
6f416815c5 riscv: Fix asan-stack clang build
commit 54c5639d8f507ebefa814f574cb6f763033a72a5 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:48:25 +01:00
Chen Lu
7a4cf25d83 riscv: fix misalgned trap vector base address
commit 64a19591a2938b170aa736443d5d3bf4c51e1388 upstream.

The trap vector marked by label .Lsecondary_park must align on a
4-byte boundary, as the {m,s}tvec is defined to require 4-byte
alignment.

Signed-off-by: Chen Lu <181250012@smail.nju.edu.cn>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Fixes: e011995e826f ("RISC-V: Move relocate and few other functions out of __init")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:48:25 +01:00
Björn Töpel
cac6b043ce riscv, bpf: Fix potential NULL dereference
commit 27de809a3d83a6199664479ebb19712533d6fd9b upstream.

The bpf_jit_binary_free() function requires a non-NULL argument. When
the RISC-V BPF JIT fails to converge in NR_JIT_ITERATIONS steps,
jit_data->header will be NULL, which triggers a NULL
dereference. Avoid this by checking the argument, prior calling the
function.

Fixes: ca6cb5447cec ("riscv, bpf: Factor common RISC-V JIT code")
Signed-off-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20211028125115.514587-1-bjorn@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:48:21 +01:00
Palmer Dabbelt
a4037dded5 RISC-V: Include clone3() on rv32
[ Upstream commit 59a4e0d5511ba61353ea9a4efdb1b86c23ecf134 ]

As far as I can tell this should be enabled on rv32 as well, I'm not
sure why it's rv64-only.  checksyscalls is complaining about our lack of
clone3() on rv32.

Fixes: 56ac5e213933 ("riscv: enable sys_clone3 syscall for rv64")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13 10:04:29 +02:00
Tong Tiangen
2c152d9da8 riscv/vdso: make arch_setup_additional_pages wait for mmap_sem for write killable
[ Upstream commit 8bb0ab3ae7a4dbe6cf32deb830cf2bdbf5736867 ]

riscv architectures relying on mmap_sem for write in their
arch_setup_additional_pages. If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-13 10:04:29 +02:00
Alexandre Ghiti
427faa29e0 riscv: Flush current cpu icache before other cpus
commit bb8958d5dc79acbd071397abb57b8756375fe1ce upstream.

On SiFive Unmatched, I recently fell onto the following BUG when booting:

[    0.000000] ftrace: allocating 36610 entries in 144 pages
[    0.000000] Oops - illegal instruction [#1]
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.1+ #5
[    0.000000] Hardware name: SiFive HiFive Unmatched A00 (DT)
[    0.000000] epc : riscv_cpuid_to_hartid_mask+0x6/0xae
[    0.000000]  ra : __sbi_rfence_v02+0xc8/0x10a
[    0.000000] epc : ffffffff80007240 ra : ffffffff80009964 sp : ffffffff81803e10
[    0.000000]  gp : ffffffff81a1ea70 tp : ffffffff8180f500 t0 : ffffffe07fe30000
[    0.000000]  t1 : 0000000000000004 t2 : 0000000000000000 s0 : ffffffff81803e60
[    0.000000]  s1 : 0000000000000000 a0 : ffffffff81a22238 a1 : ffffffff81803e10
[    0.000000]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[    0.000000]  a5 : 0000000000000000 a6 : ffffffff8000989c a7 : 0000000052464e43
[    0.000000]  s2 : ffffffff81a220c8 s3 : 0000000000000000 s4 : 0000000000000000
[    0.000000]  s5 : 0000000000000000 s6 : 0000000200000100 s7 : 0000000000000001
[    0.000000]  s8 : ffffffe07fe04040 s9 : ffffffff81a22c80 s10: 0000000000001000
[    0.000000]  s11: 0000000000000004 t3 : 0000000000000001 t4 : 0000000000000008
[    0.000000]  t5 : ffffffcf04000808 t6 : ffffffe3ffddf188
[    0.000000] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000002
[    0.000000] [<ffffffff80007240>] riscv_cpuid_to_hartid_mask+0x6/0xae
[    0.000000] [<ffffffff80009474>] sbi_remote_fence_i+0x1e/0x26
[    0.000000] [<ffffffff8000b8f4>] flush_icache_all+0x12/0x1a
[    0.000000] [<ffffffff8000666c>] patch_text_nosync+0x26/0x32
[    0.000000] [<ffffffff8000884e>] ftrace_init_nop+0x52/0x8c
[    0.000000] [<ffffffff800f051e>] ftrace_process_locs.isra.0+0x29c/0x360
[    0.000000] [<ffffffff80a0e3c6>] ftrace_init+0x80/0x130
[    0.000000] [<ffffffff80a00f8c>] start_kernel+0x5c4/0x8f6
[    0.000000] ---[ end trace f67eb9af4d8d492b ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[    0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

While ftrace is looping over a list of addresses to patch, it always failed
when patching the same function: riscv_cpuid_to_hartid_mask. Looking at the
backtrace, the illegal instruction is encountered in this same function.
However, patch_text_nosync, after patching the instructions, calls
flush_icache_range. But looking at what happens in this function:

flush_icache_range -> flush_icache_all
                   -> sbi_remote_fence_i
                   -> __sbi_rfence_v02
                   -> riscv_cpuid_to_hartid_mask

The icache and dcache of the current cpu are never synchronized between the
patching of riscv_cpuid_to_hartid_mask and calling this same function.

So fix this by flushing the current cpu's icache before asking for the other
cpus to do the same.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Fixes: fab957c11efe ("RISC-V: Atomic and Locking Code")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-13 10:04:24 +02:00
Thomas Gleixner
b9a1526d51 drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()
[ Upstream commit 4b92d4add5f6dcf21275185c997d6ecb800054cd ]

DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework
to ensure that the cache related functions are called on the upcoming CPU
because the notifier itself could run on any online CPU.

The hotplug state machine guarantees that the callbacks are invoked on the
upcoming CPU. So there is no need to have this SMP function call
obfuscation. That indirection was missed when the hotplug notifiers were
converted.

This also solves the problem of ARM64 init_cache_level() invoking ACPI
functions which take a semaphore in that context. That's invalid as SMP
function calls run with interrupts disabled. Running it just from the
callback in context of the CPU hotplug thread solves this.

Fixes: 8571890e1513 ("arm64: Add support for ACPI based firmware tables")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/871r69ersb.ffs@tglx
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26 14:08:59 +02:00
Guo Ren
133d7f93ee riscv: Fixup patch_text panic in ftrace
commit 5ad84adf5456313e285734102367c861c436c5ed upstream.

Just like arm64, we can't trace the function in the patch_text path.

Here is the bug log:

[   45.234334] Unable to handle kernel paging request at virtual address ffffffd38ae80900
[   45.242313] Oops [#1]
[   45.244600] Modules linked in:
[   45.247678] CPU: 0 PID: 11 Comm: migration/0 Not tainted 5.9.0-00025-g9b7db83-dirty #215
[   45.255797] epc: ffffffe00021689a ra : ffffffe00021718e sp : ffffffe01afabb58
[   45.262955]  gp : ffffffe00136afa0 tp : ffffffe01af94d00 t0 : 0000000000000002
[   45.270200]  t1 : 0000000000000000 t2 : 0000000000000001 s0 : ffffffe01afabc08
[   45.277443]  s1 : ffffffe0013718a8 a0 : 0000000000000000 a1 : ffffffe01afabba8
[   45.284686]  a2 : 0000000000000000 a3 : 0000000000000000 a4 : c4c16ad38ae80900
[   45.291929]  a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000052464e43
[   45.299173]  s2 : 0000000000000001 s3 : ffffffe000206a60 s4 : ffffffe000206a60
[   45.306415]  s5 : 00000000000009ec s6 : ffffffe0013718a8 s7 : c4c16ad38ae80900
[   45.313658]  s8 : 0000000000000004 s9 : 0000000000000001 s10: 0000000000000001
[   45.320902]  s11: 0000000000000003 t3 : 0000000000000001 t4 : ffffffffd192fe79
[   45.328144]  t5 : ffffffffb8f80000 t6 : 0000000000040000
[   45.333472] status: 0000000200000100 badaddr: ffffffd38ae80900 cause: 000000000000000f
[   45.341514] ---[ end trace d95102172248fdcf ]---
[   45.346176] note: migration/0[11] exited with preempt_count 1

(gdb) x /2i $pc
=> 0xffffffe00021689a <__do_proc_dointvec+196>: sd      zero,0(s7)
   0xffffffe00021689e <__do_proc_dointvec+200>: li      s11,0

(gdb) bt
0  __do_proc_dointvec (tbl_data=0x0, table=0xffffffe01afabba8,
write=0, buffer=0x0, lenp=0x7bf897061f9a0800, ppos=0x4, conv=0x0,
data=0x52464e43) at kernel/sysctl.c:581
1  0xffffffe00021718e in do_proc_dointvec (data=<optimized out>,
conv=<optimized out>, ppos=<optimized out>, lenp=<optimized out>,
buffer=<optimized out>, write=<optimized out>, table=<optimized out>)
at kernel/sysctl.c:964
2  proc_dointvec_minmax (ppos=<optimized out>, lenp=<optimized out>,
buffer=<optimized out>, write=<optimized out>, table=<optimized out>)
at kernel/sysctl.c:964
3  proc_do_static_key (table=<optimized out>, write=1, buffer=0x0,
lenp=0x0, ppos=0x7bf897061f9a0800) at kernel/sysctl.c:1643
4  0xffffffe000206792 in ftrace_make_call (rec=<optimized out>,
addr=<optimized out>) at arch/riscv/kernel/ftrace.c:109
5  0xffffffe0002c9c04 in __ftrace_replace_code
(rec=0xffffffe01ae40c30, enable=3) at kernel/trace/ftrace.c:2503
6  0xffffffe0002ca0b2 in ftrace_replace_code (mod_flags=<optimized
out>) at kernel/trace/ftrace.c:2530
7  0xffffffe0002ca26a in ftrace_modify_all_code (command=5) at
kernel/trace/ftrace.c:2677
8  0xffffffe0002ca30e in __ftrace_modify_code (data=<optimized out>)
at kernel/trace/ftrace.c:2703
9  0xffffffe0002c13b0 in multi_cpu_stop (data=0x0) at kernel/stop_machine.c:224
10 0xffffffe0002c0fde in cpu_stopper_thread (cpu=<optimized out>) at
kernel/stop_machine.c:491
11 0xffffffe0002343de in smpboot_thread_fn (data=0x0) at kernel/smpboot.c:165
12 0xffffffe00022f8b4 in kthread (_create=0xffffffe01af0c040) at
kernel/kthread.c:292
13 0xffffffe000201fac in handle_exception () at arch/riscv/kernel/entry.S:236

   0xffffffe00020678a <+114>:   auipc   ra,0xffffe
   0xffffffe00020678e <+118>:   jalr    -118(ra) # 0xffffffe000204714 <patch_text_nosync>
   0xffffffe000206792 <+122>:   snez    a0,a0

(gdb) disassemble patch_text_nosync
Dump of assembler code for function patch_text_nosync:
   0xffffffe000204714 <+0>:     addi    sp,sp,-32
   0xffffffe000204716 <+2>:     sd      s0,16(sp)
   0xffffffe000204718 <+4>:     sd      ra,24(sp)
   0xffffffe00020471a <+6>:     addi    s0,sp,32
   0xffffffe00020471c <+8>:     auipc   ra,0x0
   0xffffffe000204720 <+12>:    jalr    -384(ra) # 0xffffffe00020459c <patch_insn_write>
   0xffffffe000204724 <+16>:    beqz    a0,0xffffffe00020472e <patch_text_nosync+26>
   0xffffffe000204726 <+18>:    ld      ra,24(sp)
   0xffffffe000204728 <+20>:    ld      s0,16(sp)
   0xffffffe00020472a <+22>:    addi    sp,sp,32
   0xffffffe00020472c <+24>:    ret
   0xffffffe00020472e <+26>:    sd      a0,-24(s0)
   0xffffffe000204732 <+30>:    auipc   ra,0x4
   0xffffffe000204736 <+34>:    jalr    -1464(ra) # 0xffffffe00020817a <flush_icache_all>
   0xffffffe00020473a <+38>:    ld      a0,-24(s0)
   0xffffffe00020473e <+42>:    ld      ra,24(sp)
   0xffffffe000204740 <+44>:    ld      s0,16(sp)
   0xffffffe000204742 <+46>:    addi    sp,sp,32
   0xffffffe000204744 <+48>:    ret

(gdb) disassemble flush_icache_all-4
Dump of assembler code for function flush_icache_all:
   0xffffffe00020817a <+0>:     addi    sp,sp,-8
   0xffffffe00020817c <+2>:     sd      ra,0(sp)
   0xffffffe00020817e <+4>:     auipc   ra,0xfffff
   0xffffffe000208182 <+8>:     jalr    -1822(ra) # 0xffffffe000206a60 <ftrace_caller>
   0xffffffe000208186 <+12>:    ld      ra,0(sp)
   0xffffffe000208188 <+14>:    addi    sp,sp,8
   0xffffffe00020818a <+0>:     addi    sp,sp,-16
   0xffffffe00020818c <+2>:     sd      s0,0(sp)
   0xffffffe00020818e <+4>:     sd      ra,8(sp)
   0xffffffe000208190 <+6>:     addi    s0,sp,16
   0xffffffe000208192 <+8>:     li      a0,0
   0xffffffe000208194 <+10>:    auipc   ra,0xfffff
   0xffffffe000208198 <+14>:    jalr    -410(ra) # 0xffffffe000206ffa <sbi_remote_fence_i>
   0xffffffe00020819c <+18>:    ld      s0,0(sp)
   0xffffffe00020819e <+20>:    ld      ra,8(sp)
   0xffffffe0002081a0 <+22>:    addi    sp,sp,16
   0xffffffe0002081a2 <+24>:    ret

(gdb) frame 5
(rec=0xffffffe01ae40c30, enable=3) at kernel/trace/ftrace.c:2503
2503                    return ftrace_make_call(rec, ftrace_addr);
(gdb) p /x rec->ip
$2 = 0xffffffe00020817a -> flush_icache_all !

When we modified flush_icache_all's patchable-entry with ftrace_caller:
 - Insert ftrace_caller at flush_icache_all prologue.
 - Call flush_icache_all to sync I/Dcache, but flush_icache_all is
just we modified by half.

Link: https://lore.kernel.org/linux-riscv/CAJF2gTT=oDWesWe0JVWvTpGi60-gpbNhYLdFWN_5EbyeqoEDdw@mail.gmail.com/T/#t
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-03 10:09:29 +02:00
Guo Ren
7e2087249e riscv: Fixup wrong ftrace remove cflag
commit 67d945778099b14324811fe67c5aff2cda7a7ad5 upstream.

We must use $(CC_FLAGS_FTRACE) instead of directly using -pg. It
will cause -fpatchable-function-entry error.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-03 10:09:28 +02:00
Vincent Chen
921c2533aa riscv: Ensure the value of FP registers in the core dump file is up to date
commit 379eb01c21795edb4ca8d342503bd2183a19ec3a upstream.

The value of FP registers in the core dump file comes from the
thread.fstate. However, kernel saves the FP registers to the thread.fstate
only before scheduling out the process. If no process switch happens
during the exception handling process, kernel will not have a chance to
save the latest value of FP registers to thread.fstate. It will cause the
value of FP registers in the core dump file may be incorrect. To solve this
problem, this patch force lets kernel save the FP register into the
thread.fstate if the target task_struct equals the current.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Fixes: b8c8a9590e4f ("RISC-V: Add FP register ptrace support for gdb.")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-03 10:09:22 +02:00
Daniel Borkmann
bea9e2fd18 bpf: Introduce BPF nospec instruction for mitigating Spectre v4
[ Upstream commit f5e81d1117501546b7be050c5fbafa6efd2c722c ]

In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.

This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.

The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.

Co-developed-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-04 12:46:44 +02:00
Valentin Schneider
3c51d82d0b sched/core: Initialize the idle task with preemption disabled
[ Upstream commit f1a0a376ca0c4ef1fc3d24e3e502acbb5b795674 ]

As pointed out by commit

  de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:55:50 +02:00
Khem Raj
edcd7594ad riscv32: Use medany C model for modules
[ Upstream commit 5d2388dbf84adebeb6d9742164be8d32728e4269 ]

When CONFIG_CMODEL_MEDLOW is used it ends up generating riscv_hi20_rela
relocations in modules which are not resolved during runtime and
following errors would be seen

[    4.802714] virtio_input: target 00000000c1539090 can not be addressed by the 32-bit offset from PC = 39148b7b
[    4.854800] virtio_input: target 00000000c1539090 can not be addressed by the 32-bit offset from PC = 9774456d

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-30 08:47:21 -04:00