On Fri, Sep 16, 2022, at 7:32 AM, Rohan McLure wrote:
> The powerpc fallocate compat syscall handler is identical to the
> generic implementation provided by commit 59c10c52f573f ("riscv:
> compat: syscall: Add compat_sys_call_table implementation"), and as
> such can be removed in favour of the ge
On Fri, Sep 16, 2022, at 7:32 AM, Rohan McLure wrote:
> As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate
> compatibility handlers assume parameters are passed with 32-bit
> big-endian ABI. This affects the assignment of odd-even parameter pairs
> to the high or low words of a 64
On 16. 09. 22, 3:55, наб wrote:
According to Greg, in the context of magic numbers as defined in
magic-number.rst, "the tty layer should not need this and I'll gladly
take patches"
This stretches that definition slightly, since it multiplexes it with
the terminal number as a constant offset, but
"Nicholas Piggin" writes:
> On Thu Sep 15, 2022 at 10:47 PM AEST, Michael Ellerman wrote:
>> Nicholas Piggin writes:
>> > powerpc has a number of read-only sections and tables that are put
>> > after RO_DATA(). Move the __end_rodata symbol to cover these as well.
>> >
>> > Setting memory to read-
These tests are out-of-line only, so moving them to the
their own file allows them to be run when an arch does
not implement inline static calls.
Signed-off-by: Benjamin Gray
---
kernel/Makefile | 1 +
kernel/static_call_inline.c | 43 ---
kernel/
KUnit tests for the various combinations of caller/trampoline/target and
kernel/module. They must be run from a module loaded at runtime to
guarantee they have a different TOC to the kernel.
The tests try to mitigate the chance of panicing by restoring the
TOC after every static call. Not all poss
Implementation of out-of-line static calls for PowerPC 64-bit ELF V2 ABI.
Static calls patch an indirect branch into a direct branch at runtime.
Out-of-line specifically has a caller directly call a trampoline, and
the trampoline gets patched to directly call the target.
More context regarding the
Inserts a direct branch to the stub target when possible, replacing the
mtctr/btctr sequence.
The load into r12 could potentially be skipped too, but that change
would need to refactor the arguments to indicate that the address
does not have a separate local entry point.
This helps the static cal
Implement static call support for 64 bit V2 ABI. This requires
making sure the TOC is kept correct across kernel-module
boundaries. As a secondary concern, it tries to use the local
entry point of a target wherever possible. It does so by
checking if both tramp & target are kernel code, and falls
b
Adds a generic text patching mechanism for patches of 1, 2, 4, or 8
bytes. The patcher conditionally syncs the icache depending on if
the content will be executed (as opposed to, e.g., read-only data).
The `patch_instruction` function is reimplemented in terms of this
more generic function. This g
The callee may set a field in `st_other` to 1 to indicate r2 should be
treated as caller-saved. This means a trampoline must be used to save
the current TOC before calling it and restore it afterwards, much like
external calls.
This is necessary for supporting V2 ABI static calls that do not
prese
According to Greg, in the context of magic numbers as defined in
magic-number.rst, "the tty layer should not need this and I'll gladly
take patches"
This stretches that definition slightly, since it multiplexes it with
the terminal number as a constant offset, but is equivalent
Ref: https://lore.
> On 16 Sep 2022, at 3:32 pm, Rohan McLure wrote:
>
> V4 available here:
>
> Link:
> https://lore.kernel.org/all/20220824020548.62625-1-rmcl...@linux.ibm.com/
>
> Implement a syscall wrapper, causing arguments to handlers to be passed
> via a struct pt_regs on the stack. The syscall wrapper
> On 16 Sep 2022, at 3:32 pm, Rohan McLure wrote:
>
> Arch-specific implementations of syscall handlers are currently used
> over generic implementations for the following reasons:
>
> 1. Semantics unique to powerpc
> 2. Compatibility syscalls require 'argument padding' to comply with
> 64-
V4 available here:
Link: https://lore.kernel.org/all/20220824020548.62625-1-rmcl...@linux.ibm.com/
Implement a syscall wrapper, causing arguments to handlers to be passed
via a struct pt_regs on the stack. The syscall wrapper is implemented
for all platforms other than the Cell processor, from wh
Syscall handlers should not be invoked internally by their symbol names,
as these symbols defined by the architecture-defined SYSCALL_DEFINE
macro. Fortunately, in the case of ppc64_personality, its call to
sys_personality can be replaced with an invocation to the
equivalent ksys_personality inline
Clear user state in gprs (assign to zero) to reduce the influence of user
registers on speculation within kernel syscall handlers. Clears occur
at the very beginning of the sc and scv 0 interrupt handlers, with
restores occurring following the execution of the syscall handler.
Signed-off-by: Rohan
Syscall #82 has been implemented for 32-bit platforms in a unique way on
powerpc systems. This hack will in effect guess whether the caller is
expecting new select semantics or old select semantics. It does so via a
guess, based off the first parameter. In new select, this parameter
represents the
Interrupt handlers on 64s systems will often need to save register state
from the interrupted process to make space for loading special purpose
registers or for internal state.
Fix a comment documenting a common code path macro in the beginning of
interrupt handlers where r10 is saved to the PACA
Arch-specific implementations of syscall handlers are currently used
over generic implementations for the following reasons:
1. Semantics unique to powerpc
2. Compatibility syscalls require 'argument padding' to comply with
64-bit argument convention in ELF32 abi.
3. Parameter types or order is
As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate
compatibility handlers assume parameters are passed with 32-bit
big-endian ABI. This affects the assignment of odd-even parameter pairs
to the high or low words of a 64-bit syscall parameter.
Fix fadvise64_64 fallocate compat han
The table of syscall handlers and registered compatibility syscall
handlers has in past been produced using assembly, with function
references resolved at link time. This moves link-time errors to
compile-time, by rewriting systbl.S in C, and including the
linux/syscalls.h, linux/compat.h and asm/s
The powerpc fallocate compat syscall handler is identical to the
generic implementation provided by commit 59c10c52f573f ("riscv:
compat: syscall: Add compat_sys_call_table implementation"), and as
such can be removed in favour of the generic implementation.
A future patch series will replace more
Zero GPRS r0, r2-r11, r14-r31, on entry into the kernel for all
other interrupt sources to limit influence of user-space values
in potential speculation gadgets. The remaining gprs are overwritten by
entry macros to interrupt handlers, irrespective of whether or not a
given handler consumes these r
Add Kconfig option for enabling clearing of registers on arrival in an
interrupt handler. This reduces the speculation influence of registers
on kernel internals. The option will be consumed by 64-bit systems that
feature speculation and wish to implement this mitigation.
This patch only introduce
Restoring the register state of the interrupted thread involves issuing
a large number of predictable loads to the kernel stack frame. Issue the
REST_GPR{,S} macros to clearly signal when this is happening, and bunch
together restores at the end of the interrupt handler where the saved
value is not
This reverts commit 8875f47b7681 ("powerpc/syscall: Save r3 in regs->orig_r3
").
Save caller's original r3 state to the kernel stackframe before entering
system_call_exception. This allows for user registers to be cleared by
the time system_call_exception is entered, reducing the influence of
user
Use the convenience macros for saving/clearing/restoring gprs in keeping
with syscall calling conventions. The plural variants of these macros
can store a range of registers for concision.
This works well when the user gpr value we are hoping to save is still
live. In the syscall interrupt handler
Cause syscall handlers to be typed as follows when called indirectly
throughout the kernel. This is to allow for better type checking.
typedef long (*syscall_fn)(unsigned long, unsigned long, unsigned long,
unsigned long, unsigned long, unsigned long);
Since both 32 and
Implement syscall wrapper as per s390, x86, arm64. When enabled
cause handlers to accept parameters from a stack frame rather than
from user scratch register state. This allows for user registers to be
safely cleared in order to reduce caller influence on speculation
within syscall routine. The wra
32-bit ABIs support passing 64-bit integers by registers via argument
translation. Commit 59c10c52f573 ("riscv: compat: syscall: Add
compat_sys_call_table implementation") implements the compat_arg_u64
macro for efficiently defining little endian compatibility syscalls.
Architectures supporting bi
Avoid duplication in future patch that will define the ppc64_personality
syscall handler in terms of the SYSCALL_DEFINE and COMPAT_SYSCALL_DEFINE
macros, by extracting the common body of ppc64_personality into a helper
function.
Signed-off-by: Rohan McLure
Reviewed-by: Nicholas Piggin
---
V2 ->
The common interrupt handler prologue macro and the bad_stack
trampolines include consecutive sequences of register saves, and some
register clears. Neaten such instances by expanding use of the SAVE_GPRS
macro and employing the ZEROIZE_GPR macro when appropriate.
Also simplify an invocation of SA
Syscall handlers should not be invoked internally by their symbol names,
as these symbols defined by the architecture-defined SYSCALL_DEFINE
macro. Move the compatibility syscall definition for mmap2 to
syscalls.c, so that all mmap implementations can share a helper function.
Remove 'inline' on st
The asmlinkage macro has no special meaning in powerpc, and prior to
this patch is used sporadically on some syscall handler definitions. On
architectures that do not define asmlinkage, it resolves to extern "C"
for C++ compilers and a nop otherwise. The current invocations of
asmlinkage provide fa
Provide register zeroing macros, following the same convention as
existing register stack save/restore macros, to be used in later
change to concisely zero a sequence of consecutive gprs.
The resulting macros are called ZEROIZE_GPRS and ZEROIZE_NVGPRS, keeping
with the naming of the accompanying r
Forward declare all syscall handler prototypes where a generic prototype
is not provided in either linux/syscalls.h or linux/compat.h in
asm/syscalls.h. This is required for compile-time type-checking for
syscall handlers, which is implemented later in this series.
32-bit compatibility syscall han
Zero GPRS r14-r31 on entry into the kernel for interrupt sources to
limit influence of user-space values in potential speculation gadgets.
Prior to this commit, all other GPRS are reassigned during the common
prologue to interrupt handlers and so need not be zeroised explicitly.
This may be done s
With CONFIG_PREEMPT=y (involuntary preemption enabled), it is possible
to switch away from a task inside copy_{from,to}_user. This left the CPU
with userspace access enabled until after the next IRQ or privilege
level switch, when AMR/IAMR got reset to AMR_KU[AE]P_BLOCKED. Then, when
switching back
On Wed, May 4, 2022 at 1:18 PM Alexey Kardashevskiy wrote:
>
> When introduced, IRQFD resampling worked on POWER8 with XICS. However
> KVM on POWER9 has never implemented it - the compatibility mode code
> ("XICS-on-XIVE") misses the kvm_notify_acked_irq() call and the native
> XIVE mode does not
Const function pointers by convention live in .data.rel.ro if they need
to be relocated. Now that .data.rel.ro is linked into the read-only
region, put them in the right section. This doesn't make much practical
difference, but it will make the C conversion of sys_call_table a
smaller change as far
Follow the binutils ld internal linker script and merge .got and .toc
input sections in the .got output section.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kernel/vmlinux.lds.S | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S
b/arch/po
ELFv2 does not use function descriptors so .opd is not required.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kernel/vmlinux.lds.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S
b/arch/powerpc/kernel/vmlinux.lds.S
index ae0814063900..737825ae2ae0 1006
.sdata2 is a readonly small data section for ppc32, and .data.rel.ro
is data that needs relocating but is read-only after that so these
can both be moved to the read only memory region.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kernel/vmlinux.lds.S | 20
1 file changed
This moves linker-related tables from .data to read-only area.
Relocations are performed at early boot time before memory is protected,
after which there should be no modifications required.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kernel/vmlinux.lds.S | 42 ---
Following the example from the binutils default linker script, move
.got1 and .got2 out of .text, to just after RO_DATA.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kernel/vmlinux.lds.S | 21 +++--
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/arch/powerpc/k
powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.
Setting memory to read-only at boot is done using __init_begin, change
that that to use __end_rodata. This removes the requirement for the init
section to follow
This series is mainly about moving more things out of writable and
executable memory, and slightly moving the linker script in the
direction of the binutils ld internal linker script as we do.
Thanks,
Nick
Since v1:
- Move sys_call_table data.rel.ro patch to the end.
- And fix the changelog in th
On Wed Sep 14, 2022 at 3:39 AM AEST, Leonardo Brás wrote:
> On Mon, 2022-09-12 at 14:58 -0500, Nathan Lynch wrote:
> > Leonardo Brás writes:
> > > On Fri, 2022-09-09 at 09:04 -0500, Nathan Lynch wrote:
> > > > Leonardo Brás writes:
> > > > > On Wed, 2022-09-07 at 17:01 -0500, Nathan Lynch wrote:
On Tue Sep 13, 2022 at 10:45 PM AEST, Michael Ellerman wrote:
> In interrupt_64.S, formerly entry_64.S, there are two toc entries
> created for sys_call_table and compat_sys_call_table.
>
> These are no longer used, since the system call entry was converted from
> asm to C, so remove them.
>
Acked
Seems okay to me, it probably better go through the KVM tree though.
Acked-by: Nicholas Piggin
Thanks,
Nick
On Tue Sep 13, 2022 at 10:50 PM AEST, Alexey Kardashevskiy wrote:
> Ping? It's been a while and probably got lost :-/
>
> On 18/05/2022 16:27, Alexey Kardashevskiy wrote:
> >
> >
> > On
On Thu Sep 15, 2022 at 3:45 PM AEST, Rohan McLure wrote:
>
>
> > On 12 Sep 2022, at 8:56 pm, Nicholas Piggin wrote:
> >
> > On Wed Aug 24, 2022 at 12:05 PM AEST, Rohan McLure wrote:
> >> Cause syscall handlers to be typed as follows when called indirectly
> >> throughout the kernel.
> >>
> >> ty
On Thu Sep 15, 2022 at 4:55 PM AEST, Rohan McLure wrote:
>
>
> > On 12 Sep 2022, at 10:15 pm, Nicholas Piggin wrote:
> >
> > On Wed Aug 24, 2022 at 12:05 PM AEST, Rohan McLure wrote:
> >> Zero GPRS r0, r2-r11, r14-r31, on entry into the kernel for all
> >> other interrupt sources to limit influen
On Thu Sep 15, 2022 at 10:51 PM AEST, Michael Ellerman wrote:
> Christophe Leroy writes:
> > Le 14/09/2022 à 17:47, Nicholas Piggin a écrit :
> >> Const function pointers live in .data.rel.ro rather than .rodata because
> >> they must be relocated. This change prevents powerpc/32 from generating
>
On Thu Sep 15, 2022 at 10:47 PM AEST, Michael Ellerman wrote:
> Nicholas Piggin writes:
> > powerpc has a number of read-only sections and tables that are put
> > after RO_DATA(). Move the __end_rodata symbol to cover these as well.
> >
> > Setting memory to read-only at boot is done using __init_
On 9/2/22 05:49, Jason Gunthorpe wrote:
On Tue, Aug 16, 2022 at 08:57:13AM +0530, Ganesh Goudar wrote:
Hi,
EEH reocvery is currently serialized and these patches shorten
the time taken for EEH recovery by making the recovery to run
in parallel. The original author of these patches is Sam Bobro
tree/branch:
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
branch HEAD: 6ce5d01e7011b32600656bf90a626b1e51fb192a Add linux-next specific
files for 20220915
Error/Warning reports:
https://lore.kernel.org/linux-mm/202209150141.wgbakqmx-...@intel.com
https
> On Sep 14, 2022, at 11:42 PM, Barry Song <21cn...@gmail.com> wrote:
>
>>
>> The very idea behind TLB deferral is the opportunity it (might) provide
>> to accumulate address ranges and cpu masks so that individual TLB flush
>> can be replaced with a more cost effective range based TLB flush.
Michal Suchánek writes:
> On Tue, Sep 13, 2022 at 12:02:42PM -0500, Nathan Lynch wrote:
>> Anyway, of course I intend to support the more complex calls, but
>> supporting the simple calls actually unbreaks a lot of stuff.
>
> The thing is that supporting calls that return more than one page of
> d
Christophe Leroy writes:
> Le 14/09/2022 à 17:47, Nicholas Piggin a écrit :
>> Const function pointers live in .data.rel.ro rather than .rodata because
>> they must be relocated. This change prevents powerpc/32 from generating
>> R_PPC_UADDR32 relocations (which are not handled). The sys_call_tabl
Nicholas Piggin writes:
> powerpc has a number of read-only sections and tables that are put
> after RO_DATA(). Move the __end_rodata symbol to cover these as well.
>
> Setting memory to read-only at boot is done using __init_begin,
> change that that to use __end_rodata.
Did you just do that bec
Ensure r13 is zero from very early in boot until it gets set to the
boot paca pointer. This allows early program and mce handlers to halt
if there is no valid paca, rather than potentially run off into the
weeds. This preserves register and memory contents for low level
debugging tools.
Nothing co
The idea is to get to the point where if r13 is non-zero, then it should
contain a reasonable paca. This can be used in early boot program check
and machine check handlers to avoid running off into the weeds if they
hit before r13 has a paca.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kerne
relocate() uses r13 in early boot before it is used for the paca. Use
a different register for this so r13 is kept unchanged until it is
set to the paca pointer.
Avoid r14 as well while we're here, there's no reason not to use the
volatile registers which is a bit less surprising, and r14 could be
Use the early boot interrupt fixup in the machine check handler to allow
the machine check handler to run before interrupt endian is set up.
Branch to an early boot handler that just does a basic crash, which
allows it to run before ppc_md is set up. MSR[ME] is enabled on the boot
CPU earlier, and
In preparation for using this sequence in machine check interrupt, move
it into a macro, with a small change to make it position independent.
Signed-off-by: Nicholas Piggin
---
arch/powerpc/kernel/exceptions-64s.S | 101 +++
1 file changed, 56 insertions(+), 45 deletions(
This prevents interrupts in early boot (e.g., program check) from
enabling MSR[EE], potentially causing endian mismatch or other
crashes when reporting early boot traps.
Fixes: 4423eb5ae32ec ("powerpc/64/interrupt: make normal synchronous interrupts
enable MSR[EE] if possible")
Signed-off-by: Nic
This series is mostly 64s but has a few fixes that cover 64e too.
The main thing is the early boot machine check handler.
Thanks,
Nick
Nicholas Piggin (6):
powerpc/64: mark irqs hard disabled in boot paca
powerpc/64s/interrupt: move early boot ILE fixup into a macro
powerpc/64s: early boot
On Thu, 18 Aug 2022 15:38:37 +0200, Christophe Leroy wrote:
> Let the core handle all the chipselect bakery and replace
> transfer_one_message() by transfer_one() and prepare_message().
>
> At the time being, there is fsl_spi_cs_control() to handle
> chipselects. That function handles both GPIO an
On Thu, Sep 15, 2022 at 10:56:58AM +0800, Chen Zhongjin wrote:
> We have found some anonymous information on x86 in .rodata.
Well yes, but that's still a bunch of heuristics on our side.
> I'm not sure if those are *all* of Josh wanted on x86, however for arm64 we
> did not found that in the sam
70 matches
Mail list logo
