The address of external symbols will locate more than 32-bit offset
in 64-bit kernel with sv39 or sv48 virtual addressing.
Module loader emits the GOT and PLT entries for data symbols and
function symbols respectively.
The PLT entry is a trampoline code for jumping to the 64-bit
real address. The GOT entry is just the data symbol address.
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
In walk_stackframe, the pc now receives the address from calling
ftrace_graph_ret_addr instead of manual calculation.
Note that the original calculation,
pc = frame->ra - 4
is buggy when the instruction at the return address happened to be a
compressed inst. But since it is not a critical part of ftrace, it is
ignored for now to ease the review process.
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Once the function_graph tracer is enabled, a filtered function has the
following call sequence:
* ftracer_caller ==> on/off by ftrace_make_call/ftrace_make_nop
* ftrace_graph_caller
* ftrace_graph_call ==> on/off by ftrace_en/disable_ftrace_graph_caller
* prepare_ftrace_return
Considering the following DYNAMIC_FTRACE_WITH_REGS feature, it would be
more extendable to have a ftrace_graph_caller function, instead of
calling prepare_ftrace_return directly in ftrace_caller.
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
We now have dynamic ftrace with the following added items:
* ftrace_make_call, ftrace_make_nop (in kernel/ftrace.c)
The two functions turn each recorded call site of filtered functions
into a call to ftrace_caller or nops
* ftracce_update_ftrace_func (in kernel/ftrace.c)
turns the nops at ftrace_call into a call to a generic entry for
function tracers.
* ftrace_caller (in kernel/mcount-dyn.S)
The entry where each _mcount call sites calls to once they are
filtered to be traced.
Also, this patch fixes the semantic problems in mcount.S, which will be
treated as only a reference implementation once we have the dynamic
ftrace.
Cc: Greentime Hu <greentime@andestech.com>
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Using this helper allows us to avoid the in-kernel calls to the
sys_mmap_pgoff() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mmap_pgoff().
This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
The sbi_ prefix would seem to indicate an SBI interface, and save is not
very specific. After applying this patch, reading head.S makes more sense.
Signed-off-by: Michael Clark <michaeljclark@mac.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Interrupt is allowed during exception handling.
There are warning messages if the kernel enables the configuration
'CONFIG_DEBUG_ATOMIC_SLEEP=y'.
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23
in_atomic(): 0, irqs_disabled(): 1, pid: 43, name: ash
CPU: 0 PID: 43 Comm: ash Tainted: G W 4.15.0-rc8-00089-g89ffdae-dirty #17
Call Trace:
[<000000009abb1587>] walk_stackframe+0x0/0x7a
[<00000000d4f3d088>] ___might_sleep+0x102/0x11a
[<00000000b1fd792a>] down_read+0x18/0x28
[<000000000289ec01>] do_page_fault+0x86/0x2f6
[<00000000012441f6>] _do_fork+0x1b4/0x1e0
[<00000000f46c3e3b>] ret_from_syscall+0xa/0xe
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This tag contains the fixes we'd like to target for the 4.16 merge
window. It's not as much as I was originally hoping to do but between
glibc, the chip, and FOSDEM there just wasn't enough time to get
everything put together. As such, this merge window is essentially just
going to be small changes. This includes mostly cleanups:
* A build fix failure to the audit test cases. RISC-V doesn't have
renameat because the generic syscall ABI moved to renameat2 by the
time of our port. The syscall audit test cases don't understand this,
so I added a trivial fix. This went through mailing list review
during the 4.15 merge window, but nobody has picked it up so I think
it's best to just do this here.
* The removal of our command-line argument processing code. The
"mem_end" stuff was broken and the rest duplicated generic device tree
code. The generic code was already being called.
* Some unused/redundant code has been removed, including
__ARCH_HAVE_MMU, current_pgdir, and the initialization of init_mm.pgd.
* SUM is disabled upon taking a trap, which means that user memory is
protected during traps taking inside copy_{to,from}_user().
* The sptbr CSR has been renamed to satp in C code. We haven't changed
the assembly code in order to maintain compatibility with binutils
2.29, which doesn't understand the new name.
Additionally, we're adding some new features:
* Basic ftrace support, thanks to Alan Kao!
* Support for ZONE_DMA32. This is necessary for all the normal reasons,
but also to deal with a deficiency in the Xilinx PCIe controller we're
using on our FPGA-based systems. While the ZONE_DMA32 addition should
be sufficient for most uses, it doesn't complete the fix for the
Xilinx controller.
* TLB shootdowns now only target the harts where they're necessary,
instead of applying to all harts in the system.
These patches have all been sitting on our linux-next branch for a while
now. Due to time constraints this is all I feel comfortable submitting
during the 4.16 merge window, hopefully we'll do better next time!
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Merge tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux
Pull RISC-V updates from Palmer Dabbelt:
"This contains the fixes we'd like to target for the 4.16 merge window.
It's not as much as I was originally hoping to do but between glibc,
the chip, and FOSDEM there just wasn't enough time to get everything
put together. As such, this merge window is essentially just going to
be small changes. This includes mostly cleanups:
- A build fix failure to the audit test cases.
RISC-V doesn't have renameat because the generic syscall ABI moved
to renameat2 by the time of our port. The syscall audit test cases
don't understand this, so I added a trivial fix. This went through
mailing list review during the 4.15 merge window, but nobody has
picked it up so I think it's best to just do this here.
- The removal of our command-line argument processing code. The
"mem_end" stuff was broken and the rest duplicated generic device
tree code. The generic code was already being called.
- Some unused/redundant code has been removed, including
__ARCH_HAVE_MMU, current_pgdir, and the initialization of
init_mm.pgd.
- SUM is disabled upon taking a trap, which means that user memory is
protected during traps taking inside copy_{to,from}_user().
- The sptbr CSR has been renamed to satp in C code. We haven't
changed the assembly code in order to maintain compatibility with
binutils 2.29, which doesn't understand the new name.
Additionally, we're adding some new features:
- Basic ftrace support, thanks to Alan Kao!
- Support for ZONE_DMA32.
This is necessary for all the normal reasons, but also to deal with
a deficiency in the Xilinx PCIe controller we're using on our
FPGA-based systems. While the ZONE_DMA32 addition should be
sufficient for most uses, it doesn't complete the fix for the
Xilinx controller.
- TLB shootdowns now only target the harts where they're necessary,
instead of applying to all harts in the system.
These patches have all been sitting on our linux-next branch for a
while now. Due to time constraints this is all I feel comfortable
submitting during the 4.16 merge window, hopefully we'll do better
next time!"
[ Note to self: "harts" is RISC-V speak for "hardware threads". I had
to look that up. - Linus ]
* tag 'riscv-for-linus-4.16-merge_window' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
riscv: inline set_pgdir into its only caller
riscv: rename sptbr to satp
riscv: don't read back satp in paging_init
riscv: remove the unused current_pgdir function
riscv: add ZONE_DMA32
RISC-V: Limit the scope of TLB shootdowns
riscv: disable SUM in the exception handler
riscv: remove redundant unlikely()
riscv: remove unused __ARCH_HAVE_MMU define
riscv/ftrace: Add basic support
RISC-V: Remove mem_end command line processing
RISC-V: Remove duplicate command-line parsing logic
audit: Avoid build failures on systems without renameat
Pull asm/uaccess.h whack-a-mole from Al Viro:
"It's linux/uaccess.h, damnit... Oh, well - eventually they'll stop
cropping up..."
* 'work.whack-a-mole' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
asm-prototypes.h: use linux/uaccess.h, not asm/uaccess.h
riscv: use linux/uaccess.h, not asm/uaccess.h...
ppc: for put_user() pull linux/uaccess.h, not asm/uaccess.h
satp is the name used by the current privileged spec 1.10, use it
instead of the old name. The most recent release binutils release
(2.29) doesn't know about the satp name yet, so stick to the name from
the previous privileged ISA release and comment on the fact.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch allows devices that require memory that can be addressed
using 32-bit addresses to work easily on RISC-V systems. The newly
improved dma-direct ops will tap into this pool automatically for
32-bit addressing.
Based on an earlier patch from Wesley W. Terpstra.
CC: Wesley W. Terpstra <terpstra@sifive.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The SUM bit is enabled at the beginning of the copy_{to,from}_user and
{get,put}_user routines, and cleared before they return. But these user
copy helper can be interrupted by exceptions, in which case the SUM bit
will remain set, which leads to elevated privileges for the code running
in exception context, as that can now access userspace address space
unconditionally. This frequently happens when the user copy routines
access freshly allocated user memory that hasn't been faulted in, and a
pagefault needs to be taken before the user copy routines can continue.
Fix this by unconditionally clearing SUM when the exception handler is
called - the restore code will automatically restore it based on the
saved value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
IS_ERR_VALUE() already implies unlikely(), so it can be omitted.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch contains basic ftrace support for RV64I platform.
Specifically, function tracer (HAVE_FUNCTION_TRACER), function graph
tracer (HAVE_FUNCTION_GRAPH_TRACER), and a frame pointer test
(HAVE_FUNCTION_GRAPH_FP_TEST) are implemented following the
instructions in Documentation/trace/ftrace-design.txt.
Note that the functions in both ftrace.c and setup.c should not be
hooked with the compiler's -pg option: to prevent infinite self-
referencing for the former, and to ignore early setup stuff for the
latter.
Signed-off-by: Alan Kao <alankao@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This is just some cruft left over from before the port converted to
device tree. The right way to handle memory regions is to specify them
in the device tree, which BBL (our simplest bootloader) is already
capable of doing. This patch simply removes the cruft.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
builtin_cmdline handling is present in drivers/of/fdt.c so the
duplicate logic in arch/riscv/setup.c results in duplication of
the builtin command line. e.g. CONFIG_CMDLINE="root=/dev/vda ro"
gets appended twice and gives "root=/dev/vda ro root=/dev/vda ro"
Before this patch:
[ 0.000000] Kernel command line: root=/dev/vda ro root=/dev/vda ro
After this patch:
[ 0.000000] Kernel command line: root=/dev/vda ro
Signed-off-by: Michael Clark <mjc@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
We were hoping to avoid making this visible to userspace, but it looks
like we're going to have to because QEMU's user-mode emulation doesn't
want to emulate a vDSO. Having vDSO-only system calls was a bit
unothodox anyway, so I think in this case it's OK to just make the
actual system call number public.
This patch simply moves the definition of __NR_riscv_flush_icache
availiable to userspace, which results in the deletion of the now empty
vdso-syscalls.h.
Changes since v1:
* I've moved the definition into uapi/asm/syscalls.h rathen than
uapi/asm/unistd.h. This allows me to keep asm/unistd.h, so we can
keep the syscall table macros sane.
* As a side effect of the above, this no longer disables all system
calls on RISC-V. Whoops!
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This is code that probably should never have made it into the kernel in
the first place: it depends on a driver that hadn't been reviewed yet.
During the HVC_SBI_RISCV review process a better way of doing this was
suggested, but that means this code is defunct. It's compile-time
disabled in 4.15 because the driver isn't in, so I think it's safe to
just remove this for now.
CC: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
In the current code, there is a ! logical NOT where a bitwise ~ NOT was
intended. It means that we never return -EINVAL.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Olaf said: Here's a short series of patches that produces a working
allmodconfig. Would be nice to see them go in so we can add build
coverage.
I've dropped patches 8 and 10 from the original set:
* [PATCH 08/10] (RISC-V: Set __ARCH_WANT_RENAMEAT to pick up generic
version) has a better fix that I've sent out for review, we don't want
renameat.
* [PATCH 10/10] (input: joystick: riscv has get_cycles) has already been
taken into Dmitry Torokhov's tree.
We used to have some cmpxchg syscalls. They're no longer there, so we
no longer need the include.
CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Despite RISC-V having a direct 'fence.i' instruction available to
userspace (which we can't trap!), that's not actually viable when
running on Linux because the kernel might schedule a process on another
hart. There is no way for userspace to handle this without invoking the
kernel (as it doesn't know the thread->hart mappings), so we've defined
a RISC-V specific system call to flush the instruction cache.
This patch adds both a system call and a VDSO entry. If possible, we'd
like to avoid having the system call be considered part of the
user-facing ABI and instead restrict that to the VDSO entry -- both just
in general to avoid having additional user-visible ABI to maintain, and
because we'd prefer that users just call the VDSO entry because there
might be a better way to do this in the future (ie, one that doesn't
require entering the kernel).
Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The RISC-V ISA allows for instruction caches that are not coherent WRT
stores, even on a single hart. As a result, we need to explicitly flush
the instruction cache whenever marking a dirty page as executable in
order to preserve the correct system behavior.
Local instruction caches aren't that scary (our implementations actually
flush the cache, but RISC-V is defined to allow higher-performance
implementations to exist), but RISC-V defines no way to perform an
instruction cache shootdown. When explicitly asked to do so we can
shoot down remote instruction caches via an IPI, but this is a bit on
the slow side.
Instead of requiring an IPI to all harts whenever marking a page as
executable, we simply flush the currently running harts. In order to
maintain correct behavior, we additionally mark every other hart as
needing a deferred instruction cache which will be taken before anything
runs on it.
Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Fixes the following on allmodconfig build:
profile.c:(.text+0x3e4): undefined reference to `setup_profiling_timer'
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
These are the ones needed by current allmodconfig, so add them instead
of everything other architectures are exporting -- the rest can be
added on demand later if needed.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Needed by some modules (exported by other architectures).
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
For now these are just placeholders that execute the syscall. We will
later optimize them to avoid kernel crossings, but we'd like to have the
VDSO entries from the first released kernel version to make the ABI
simpler.
Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch contains all the build infrastructure that actually enables
the RISC-V port. This includes Makefiles, linker scripts, and Kconfig
files. It also contains the only top-level change, which adds RISC-V to
the list of architectures that need a sed run to produce the ARCH
variable when building locally.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling. It also contains some generic code that is ABI visible.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This patch contains the implementation of tasks on RISC-V, most of which
is involved in task switching.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux. It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system. When a file was
init-related this patch contains the entire file.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
