Jan Höppner says:
====================
Quite a lot of the tape device driver code is outdated as devices and
storage systems supported by that code aren't supported by IBM anymore for
a long time. Especially physical tape devices are not supported or used
directly anymore.
The only tape storage system supported by IBM is the Virtual Tape Server
(VTS) family with TS7700 systems [1]. Host systems will only talk to VTS
and are presented with the virtualized 3490E tape device type only. VTS can
and still uses tape libraries with physical 3592 cartridges as storage
backends (e.g. TS4500). However, these are never seen by any host.
The general goal/idea for the tape device driver is to only support VTS
from now on. This series gets rid of old outdated code that is not
relevant to VTS. There is probably quite a bit more that could be
cleaned up or could be improved. However, this is a first run to cleanup
the code base and somewhat reduce maintenance burden.
[1] https://www.ibm.com/products/ts7700
[2] https://www.ibm.com/products/ts4500
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The driver now exclusively supports 3490 tape devices, given support for
3480 tape devices has been removed. Update the device driver name, its
source file name, and change any occurrences of "34xx/34XX" to "3490" in
the source code and comments.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Quite a few Error Recovery Action (ERA) codes and sense data entries are
not relevant anymore for the Virtual Tape Server (VTS) and are not being
used by VTS. Most of them were relevant for actual physical errors when
a tape cartridge got stuck or a tape didn't rewind properly for example.
Remove these codes from the sense data analysis as it's dead code
anyway.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The only supported device type by the Virtual Tape Server is 3490. The
3480 device type was an old physical tape model and doesn't exist
anymore. Remove 3480 from the list and any mention of it.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Quite a few command definitions are either not used or don't exist for
3490 tape devices on Virtual Tape Servers (VTS). Cleanup the list, which
makes it easier to understand what commands are actually implemented by
the driver. The lists below outline the exact reason for the removal.
Description for existing commands are adapted to reflect the removal of
support for old device types.
The following commands don't exist in VTS for 3490 devices and are
unused:
INVALID_00 0x00
DIAG_MODE_SET 0x0B
FORCE_STREAM_CNT 0xEB
LOOP_WRITE_TO_READ 0x8B
MODE_SET_C3 0xC3
MODE_SET_CB 0xCB
MODE_SET_D3 0xD3
NEW_MODE_SET 0xEB
RELEASE 0xD4
REQ_TRK_IN_ERROR 0x1B
RESERVE 0xF4
SET_DIAGNOSE 0x4B
The following command definitions are not used:
CONTROL_ACCESS 0xE3
PERF_SUBSYS_FUNC 0x77
READ_BACKWARD 0x0C
READ_BUFFER 0x12
READ_BUFF_LOG 0x24
READ_CONFIG_DATA 0xFA
READ_DEV_CHAR 0x64
READ_MESSAGE_ID 0x4E
READ_SUBSYS_DATA 0x3E
SENSE_GROUP_ID 0x34
SENSE_ID 0xE4
SET_GROUP_ID 0xAF
SET_INTERFACE_ID 0x73
SET_TAPE_WRITE_IMMED 0xC3
SUSPEND 0x5B
SYNC 0x43
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
For real 3490 tape models a logical block was composed of a direction
bit (wrap), a segment number, a format mode, and a logical block number.
This is represented in a 4byte identifier.
The Virtual Tape Server (VTS) emulates 3490 tape devices and uses a
stripped block id format where bit 0-9 of the 4byte identifier are
always 0. Bit 10-31 represent the logical block number.
All tapes use the 3480-2 XF format, which was defined via
TAPE34XX_FMT_3480_2_XF but never used. There is also no special handling
required anymore as this is the only format being used.
Since VTS doesn't require any special handling of block ids and format,
corresponding code is removed.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The LOAD_DISPLAY (LDD) X'9F' is still accepted by the Virtual Tape
Server (VTS) but does not perform any action.
Remove all functions and definitions related to this command.
The tape_34xx_ioctl() function is also removed as it was mainly used to
handle additional ioctl functionality. LOAD_DISPLAY was the only left
case. All other ioctls are handled in tapechar_ioctl().
With LOAD_DISPLAY, the remaining definitions in asm/tape390.h are gone.
Delete the file.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Physical 3590/3592 tape models are not supported anymore for a very long
time. The Virtual Tape Server (VTS) emulates and presents only 3490E
models to the host. This is the only supported model and storage server.
Remove the entire code base for 3590/3592 models as it can be considered
dead code for quite some time already.
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Currently, if the command line passed to kexec_file_load() exceeds
the supported limit of the kernel being kexec'd, -EINVAL is returned
to userspace, which is consistent across architectures. Since
-EINVAL is not specific to this case, the kexec tool cannot provide
a specific reason for the failure. Many architectures emit an error
message in this case. Add a similar error message, including the
effective limit, since the command line length is configurable.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Enable BLK_DEV_NULL_BLK as module in defconfig and debug_defconfig, so the
Null Test Block Device Driver can be easily used for testing purposes.
Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Running commands
# ./perf record -IR0,R1 -a sleep 1
extracts and displays register value of general purpose register r1 and r0.
However the value displayed of any register is random and does not
reflect the register value recorded at the time of the sample interrupt.
The sampling device driver on s390 creates a very large buffer
for the hardware to store the samples. Only when that large buffer
gets full an interrupt is generated and many hundreds of sample
entries are processed and copied to the kernel ring buffer and
eventually get copied to the perf tool. It is during the copy
to the kernel ring buffer that each sample is processed (on s390)
and at that time the register values are extracted.
This is not the original goal, the register values should be read
when the samples are created not when the samples are copied to the
kernel ring buffer.
Prevent this event from being installed in the first place and
return -EOPNOTSUPP. This is already the case for PERF_SAMPLE_REGS_USER.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Jan Polensky <japo@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Define CONFIG_ILLEGAL_POINTER_VALUE to the eye-catching non-zero value
of 0xdead000000000000, consistent with other architectures. Assert at
compile-time that the poison pointers that include/linux/poison.h
defines based on this illegal pointer are beyond the largest useful
virtual addresses. Also, assert at compile-time that the range of poison
pointers per include/linux/poison.h (currently a range of less than
0x10000 addresses) does not overlap with the range used for address
handles for s390's non-MIO PCI instructions.
This enables s390 to track the DMA mappings by the network stack's
page_pool that was introduced with [0]. Other functional changes are not
intended.
Other archictectures have introduced this for various other reasons with
commit 5c178472af ("riscv: define ILLEGAL_POINTER_VALUE for 64bit")
commit f6853eb561 ("powerpc/64: Define ILLEGAL_POINTER_VALUE for 64-bit")
commit bf0c4e0473 ("arm64: kconfig: Move LIST_POISON to a safe value")
commit a29815a333 ("core, x86: make LIST_POISON less deadly")
[0] https://lore.kernel.org/all/20250409-page-pool-track-dma-v9-0-6a9ef2e0cba8@redhat.com/
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Heiko Carstens says:
====================
v2:
- Use generic WARN() implementation in case of gcc-8, which avoids the need
to raise the minimum gcc version to gcc-9 for (only) s390
- Add couple of additional ifdef guards to avoid compile errors and
warnings
v1 ([1]):
Use the generic infrastructure introduced by Peter Zijlstra [2] to implement
an exception based WARN() and WARN_ONCE() similar to x86.
Due to some compiler oddities on s390 this requires to raise the minimum gcc
version to 9. Maybe there are ways to avoid this, but I failed to find a
working solution. Details are in the patch descriptions.
Just posting this now to also get some compile bot testing, since I'm afraid
there might be some compiler version / config option around where even this
new approach breaks.
Peter, since you were wondering: your generic infrastructure pieces work very
nice. Looking at the x86 and s390 implementation: it might be possible to make
things even more generic since both __WARN_printf(), and WARN_ONCE() are
identical; it looks like only __WARN_print_arg() needs to be provided.
[1] https://lore.kernel.org/all/20251209121701.1856271-1-hca@linux.ibm.com/
[2] https://lore.kernel.org/all/20251110114633.202485143@infradead.org/
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
For the exception based __WARN_trap() implementation it is technically not
necessary to prevent tail-call optimization, however it may be confusing to
see warning messages like:
WARNING: arch/s390/kernel/setup.c:1017 at foobar+0x2c/0x50, CPU#0: swapper/0/0
together with a disassembly of a different function caused by tail-call
optimization for the __WARN_trap() call. Prevent that by adding an empty
asm statement. This generates slightly worse code, but should hopefully
avoid confusion.
With this the output looks like:
WARNING: arch/s390/kernel/setup.c:1017 at foobar+0x2c/0x50, CPU#0: swapper/0/0
...
Krnl PSW : 0704c00180000000 000003ffe0119788 (foobar+0x38/0x50)
...
Krnl Code: 000003ffe0119776: e3e0f0980024 stg %r14,152(%r15)
000003ffe011977c: c02000b8992a larl %r2,000003ffe182c9d0
*000003ffe0119782: c0e5007270b7 brasl %r14,000003ffe0f678f0
>000003ffe0119788: ebeff0a00004 lmg %r14,%r15,160(%r15)
000003ffe011978e: 07fe bcr 15,%r14
000003ffe0119790: 47000700 bc 0,1792
000003ffe0119794: 0707 bcr 0,%r7
000003ffe0119796: 0707 bcr 0,%r7
Call Trace:
[<000003ffe0119788>] foobar+0x38/0x50
[<000003ffe185bc2e>] arch_cpu_finalize_init+0x26/0x60
[<000003ffe185654c>] start_kernel+0x53c/0x5d8
[<000003ffe010002e>] startup_continue+0x2e/0x40
A better solution would be to replace or patch the branch instruction to
__WARN_trap() with the monitor call instruction, similar to what is done
for x86 [1]. However s390 does not support static_cond_calls(). Therefore
use the simple approach for the time being.
[1] commit 860238af7a ("x86_64/bug: Inline the UD1")
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
In order to avoid rather pointless warning disassemblies of __WARN_trap()
set the PSW address to the return address of the function which called
__WARN_trap(). This is the address to which __WARN_trap() would return
in any case.
The result is a disassembly of the function which called __WARN_trap(),
which is much more helpful.
Before:
WARNING: arch/s390/kernel/setup.c:1017 at foobar+0x2c/0x20, CPU#0: swapper/0/0
...
Krnl PSW : 0704c00180000000 000003ffe0f675f4 (__WARN_trap+0x4/0x10)
...
Krnl Code: 000003ffe0f675ec: 0707 bcr 0,%r7
000003ffe0f675ee: 0707 bcr 0,%r7
*000003ffe0f675f0: af000001 mc 1,0
>000003ffe0f675f4: 07fe bcr 15,%r14
000003ffe0f675f6: 47000700 bc 0,1792
000003ffe0f675fa: 0707 bcr 0,%r7
000003ffe0f675fc: 0707 bcr 0,%r7
000003ffe0f675fe: 0707 bcr 0,%r7
Call Trace:
[<000003ffe0f675f4>] __WARN_trap+0x4/0x10
[<000003ffe185bc2e>] arch_cpu_finalize_init+0x26/0x60
[<000003ffe185654c>] start_kernel+0x53c/0x5d8
[<000003ffe010002e>] startup_continue+0x2e/0x40
Afterwards:
WARNING: arch/s390/kernel/setup.c:1017 at foobar+0x12/0x30, CPU#0: swapper/0/0
...
Krnl PSW : 0704c00180000000 000003ffe185bc2e (arch_cpu_finalize_init+0x26/0x60)
...
Krnl Code: 000003ffe185bc1c: e3f0ff98ff71 lay %r15,-104(%r15)
000003ffe185bc22: e3e0f0980024 stg %r14,152(%r15)
*000003ffe185bc28: c0e5ff45ed94 brasl %r14,000003ffe0119750
>000003ffe185bc2e: c0e5ffa052b9 brasl %r14,000003ffe0c661a0
000003ffe185bc34: c020fffe86d6 larl %r2,000003ffe182c9e0
000003ffe185bc3a: e548f0a80006 mvghi 168(%r15),6
000003ffe185bc40: e548f0a00005 mvghi 160(%r15),5
000003ffe185bc46: a7690004 lghi %r6,4
Call Trace:
[<000003ffe185bc2e>] arch_cpu_finalize_init+0x26/0x60
[<000003ffe185654c>] start_kernel+0x53c/0x5d8
[<000003ffe010002e>] startup_continue+0x2e/0x40
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This is the s390 variant of commit 11bb4944f0 ("x86/bug: Implement
WARN_ONCE()").
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
In case of a monitor call program check the CPU stores the monitor code to
lowcore. Let the program check handler copy it to the pt_regs structure so
it can be used by the monitor call exception handler.
Instead of increasing the pt_regs size add a union which contains both
orig_gpr2 and monitor_code, since orig_gpr2 is not used in case of a
program check.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The first operand address of the monitor call (mc) instruction is the
monitor code. Currently the monitor code is ignored, but this will
change. Therefore add and use MONCODE_BUG instead of a hardcoded zero.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This is just the s390 variant of commit 4f1b701f24 ("x86/bug: Use
BUG_FORMAT for DEBUG_BUGVERBOSE_DETAILED").
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Rewrite the bug inline assembly so it uses input operands again instead of
pure macro replacements. This more or less reverts the conversion done when
'cond_str' support was added [1].
Reason for this is that the upcoming __WARN_printf() implementation
requires an inline assembly with an output operand. At the same time input
strings (format specifier and condition string) may contain the special '%'
character. As soon as an inline assembly is specified to have input/output
operands the '%' has a special meaning: e.g. converting the existing
#define __BUG_FLAGS(cond_str, flags) \
asm_inline volatile(__stringify(ASM_BUG_FLAGS(cond_str, flags)));
to
#define __BUG_FLAGS(cond_str, flags) \
asm_inline volatile(__stringify(ASM_BUG_FLAGS(cond_str, flags))::);
will result in a compile error as soon as 'cond_str' contains a '%'
character:
net/core/neighbour.c: In function ‘neigh_table_init’:
././include/linux/compiler_types.h:546:20: error: invalid 'asm': invalid %-code
...
net/core/neighbour.c:1838:17: note: in expansion of macro ‘WARN_ON’
1838 | WARN_ON(tbl->entry_size % NEIGH_PRIV_ALIGN);
| ^~~~~~~
Convert the code, use immediate operands, and also add comments similar to
x86 which are emitted to the generated assembly file, which makes debugging
much easier.
Note: since gcc-8 does not support strings as immediate input operands,
guard the new implementation with CC_HAS_ASM_IMMEDIATE_STRINGS and fallback
to the generic non-exception based warning implementation for incompatible
compilers.
[1] 6584ff203a ("bugs/s390: Use 'cond_str' in __EMIT_BUG()")
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Upcoming changes to s390 specific inline assemblies require the usage of
strings as immediate input operands. This works only with gcc-9 and newer
compilers. With gcc-8 this leads to a compile error:
void bar(void) { asm volatile("" :: "i" ("foo")); }
Results in:
In function 'bar':
warning: asm operand 0 probably doesn't match constraints
asm volatile("" :: "i" ("foo"));
^~~
error: impossible constraint in 'asm'
Provide a CC_HAS_ASM_IMMEDIATE_STRINGS config option which allows to tell
if the compiler supports strings as immediate input operands.
Based on that conditional code can be provided.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
While pci_read() and pci_write() have returned errno values since their
inception with commit cd24834130 ("s390/pci: base support") other
config accessors in particular pci_generic_config_read() as well as
pci_generic_config_write() return specific error values which are then
converted to errno by pcibios_err_to_errno(). Since latter does handle
the case where the error value already looks like an errno the previous
behavior is unlikely to cause actual issues.
Still, for consistency and in case any caller explicitly checks error
values align pci_read() and pci_write() with the generic accessors.
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
On s390 PCI busses and slots with multiple functions may have holes
because PCI functions are passed-through by the hypervisor on a per
function basis and some functions may be in standby or reserved. This
fact is indicated by returning true from the
hypervisor_isolated_pci_functions() helper and triggers common code to
scan all possible devfn values. Via pci_scan_single_device() this in
turn causes config reads for the device and vendor IDs, even for PCI
functions which are in standby and thereofore disabled.
So far these futile config reads, as well as potentially writes, which
can never succeed were handled by the PCI load/store instructions
themselves. This works as the platform just returns an error for
a disabled and thus not usable function handle. It does cause spamming
of error logs and additional overhead though.
Instead check if the used function handle is enabled in zpci_cfg_load()
and zpci_cfg_write() and if not enable directly return -ENODEV. Also
refactor zpci_cfg_load() and zpci_cfg_store() slightly to accommodate
the new logic while meeting modern kernel style guidelines.
Cc: stable@vger.kernel.org
Fixes: a50297cf82 ("s390/pci: separate zbus creation from scanning")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Heiko Carstens says:
====================
The option to select PREEMPT_NONE will go away for all architectures which
support PREEMPT_LAZY [1]. Until now all distributions provide kernels built
with PREEMPT_NONE enabled for s390. In particular this means that all
preempt_disable() / preempt_enable() pairs are optimized away during
compile time.
With PREEMPT_LAZY this is not the case. Switching to PREEMPT_LAZY leads
to a kernel image size increase of ~218kb (defconfig, gcc15).
s390 provides optimized preempt primitives, however there is still room for
improvement. Since support for relocatable lowcore was added access to
preempt_count in lowcore requires an extra call of get_lowcore(), which
generates an extra instruction. Also all instructions have to use a base
register which is not zero to access preempt_count.
Address this by adding a couple of inline assemblies with alternatives.
This generates better code and reduces the size of a PREEMPT_LAZY built
kernel image by ~58kb.
[1] https://lore.kernel.org/all/20251219101502.GB1132199@noisy.programming.kicks-ass.net/
====================
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Provide an inline assembly using alternatives to avoid the need of a
base register due to relocatable lowcore when adding or subtracting
small constants from preempt_count.
Main user is preempt_enable(), which subtracts one from preempt_count
and tests if the result is zero.
With this the generated code changes from
1000b8: a7 19 00 00 lghi %r1,0
1000bc: eb ff 13 a8 00 6e alsi 936(%r1),-1
1000c2: a7 54 00 05 jnhe 1000cc <__rcu_read_unlock+0x14>
to something like this:
1000b8: eb ff 03 a8 00 6e alsi 936,-1
1000be: a7 54 00 05 jnhe 1000c8 <__rcu_read_unlock+0x10>
Kernel image size is reduced by 45kb (bloat-o-meter -t, defconfig, gcc15).
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With the empty define __is_enabled(__HAVE_ASM_FLAG_OUTPUTS__)
evaluates to false. Therefore let __HAVE_ASM_FLAG_OUTPUTS__ define 1
if it is defined.
This allows to make use of __is_defined(__HAVE_ASM_FLAG_OUTPUTS__)
like expected.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Provide an inline assembly using alternatives to avoid the need of a
base register due to relocatable lowcore when adding or subtracting
small constants from preempt_count.
Main user is preempt_disable(), which subtracts one from
preempt_count. With this the generated code changes from
10012c: a7 b9 00 00 lghi %r11,0
100130: eb 01 b3 a8 00 6a asi 936(%r11),1
to something like this:
10012c: eb 01 03 a8 00 6a asi 936,1
Kernel image size is reduced by 13kb (bloat-o-meter -t, defconfig, gcc15).
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Provide an inline assembly using alternatives to avoid the need of
a base register when reading preempt_count() from lowcore. Use the
LLGT instruction, which reads only the least significant 31 bits of
preempt_count. This masks out the encoded PREEMPT_NEED_RESCHED bit.
Generated code is changed from
000000000046e5d0 <vfree>:
46e5d0: c0 04 00 00 00 00 jgnop 46e5d0 <vfree>
46e5d6: a7 39 00 00 lghi %r3,0
46e5da: 58 10 33 a8 l %r1,936(%r3)
46e5de: c0 1b 00 ff ff 00 nilf %r1,16776960
46e5e4: a7 74 00 11 jne 46e606 <vfree+0x36>
to something like this:
000000000046e5d0 <vfree>:
46e5d0: c0 04 00 00 00 00 jgnop 46e5d0 <vfree>
46e5d6: e3 10 03 a8 00 17 llgt %r1,936
46e5dc: ec 41 28 b7 00 55 risbgz %r4,%r1,40,55
46e5e2: a7 74 00 0f jne 46e600 <vfree+0x30>
Overall savings are only 82 bytes according to bloat-o-meter. This
is because of different inlining decisions, and there aren't many
preempt_count() users in the kernel.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add missing s into ap_intructions_available.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Jimmy Brisson <jbrisson@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The generic CC_CAN_LINK detection relies on -m32/-m64 compiler flags.
Some s390 toolchains use -m31 instead but that is not supported in the
kernel.
Make the logic easier to understand and allow the simplification of the
generic CC_CAN_LINK by using a tailored implementation.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Revisit and rework module parameter permissions for AP bus and zcrypt
device drivers.
In general all sysfs permissions for AP bus and zcrypt parameters should be
0444 so that user space tools like lszcrypt can read the current value of
module parameters.
Some exceptions are only for some internal tweak parameters like
ap_msg_pool_min_items and zcrypt_mempool_threshold which should only be
readable by an administrator.
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Convert the function macros user_mode(), instruction_pointer(), and
user_stack_pointer() to inline functions, to align their definition
with x86 and arm64.
Use const qualifier on struct pt_regs pointer parameters to prevent
compiler warnings:
arch/s390/kernel/stacktrace.c: In function ‘arch_stack_walk_user_common’:
arch/s390/kernel/stacktrace.c:114:34: warning: passing argument 1 of
‘instruction_pointer’ discards ‘const’ qualifier from pointer target
type [-Wdiscarded-qualifiers]
...
arch/s390/kernel/stacktrace.c:117:48: warning: passing argument 1 of
‘user_stack_pointer’ discards ‘const’ qualifier from pointer target
type [-Wdiscarded-qualifiers]
...
While at it add const qualifier to all struct pt_regs pointer parameters
that are accessed read-only and use __always_inline instead of inline to
harmonize the helper functions.
[hca@linux.ibm.com: Use psw_bits() helper]
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add -Wno-default-const-init-unsafe to purgatory KBUILD_CFLAGS, similar
to scripts/Makefile.extrawarn, since clang generates warnings for the
dummy variable in typecheck():
CC arch/s390/purgatory/purgatory.o
arch/s390/include/asm/ptrace.h:221:9: warning: default initialization of an object of type 'typeof (regs->psw)' (aka 'const psw_t') leaves the object uninitialized [-Wdefault-const-init-var-unsafe]
221 | return psw_bits(regs->psw).pstate;
| ^
arch/s390/include/asm/ptrace.h:98:2: note: expanded from macro 'psw_bits'
98 | typecheck(psw_t, __psw); \
| ^
include/linux/typecheck.h:11:12: note: expanded from macro 'typecheck'
11 | typeof(x) __dummy2; \
| ^
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add -Wno-default-const-init-unsafe to boot KBUILD_CFLAGS, similar to
scripts/Makefile.extrawarn, since clang generates warnings for the dummy
variable in typecheck():
CC arch/s390/boot/version.o
arch/s390/include/asm/ptrace.h:221:9: warning: default initialization of an object of type 'typeof (regs->psw)' (aka 'const psw_t') leaves the object uninitialized [-Wdefault-const-init-var-unsafe]
221 | return psw_bits(regs->psw).pstate;
| ^
arch/s390/include/asm/ptrace.h:98:2: note: expanded from macro 'psw_bits'
98 | typecheck(psw_t, __psw); \
| ^
include/linux/typecheck.h:11:12: note: expanded from macro 'typecheck'
11 | typeof(x) __dummy2; \
| ^
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
These patches fix a typo and make the coccicheck script more robust by
ensuring that only compatible semantic patches are executed for the
chosen mode.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
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Merge tag 'coccinelle-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux
Pull Coccinelle fixes from Julia Lawall:
"These fix a typo and make the coccicheck script more robust by
ensuring that only compatible semantic patches are executed for the
chosen mode"
* tag 'coccinelle-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
Coccinelle: pm_runtime: Fix typo in report message
scripts: coccicheck: filter *.cocci files by MODE
- a quirk for i8042 to better handle another TUXEDO model
- a quirk to atkbd to handle incorcet behavior of HONOR FMB-P internal
keyboard
- a definition for a new ABS_SND_PROFILE event
- fixes to alps and lkkbd drivers to reliably shut down pending work on
removal
- a fix to apple_z2 driver tightening input report parsing
- a fix for "off-by-one" error when validating config in ti_am335x_tsc
driver
- addition of CRKD Guitars device IDs to xpad driver.
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Merge tag 'input-for-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input fixes from Dmitry Torokhov:
- a quirk for i8042 to better handle another TUXEDO model
- a quirk to atkbd to handle incorcet behavior of HONOR FMB-P internal
keyboard
- a definition for a new ABS_SND_PROFILE event
- fixes to alps and lkkbd drivers to reliably shut down pending work on
removal
- a fix to apple_z2 driver tightening input report parsing
- a fix for "off-by-one" error when validating config in ti_am335x_tsc
driver
- addition of CRKD Guitars device IDs to xpad driver.
* tag 'input-for-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: ti_am335x_tsc - fix off-by-one error in wire_order validation
Input: xpad - add support for CRKD Guitars
Input: add ABS_SND_PROFILE
Input: apple_z2 - fix reading incorrect reports after exiting sleep
Input: alps - fix use-after-free bugs caused by dev3_register_work
Input: i8042 - add TUXEDO InfinityBook Max Gen10 AMD to i8042 quirk table
Input: atkbd - skip deactivate for HONOR FMB-P's internal keyboard
Input: lkkbd - disable pending work before freeing device
Enhance the coccicheck script to filter *.cocci files based on the
specified MODE (e.g., report, patch). This ensures that only compatible
semantic patch files are executed, preventing errors such as:
"virtual rule report not supported"
This error occurs when a .cocci file does not define a 'virtual <MODE>'
rule, yet is executed in that mode.
For example:
make coccicheck M=drivers/hwtracing/coresight/ MODE=report
In this case, running "secs_to_jiffies.cocci" would trigger the error
because it lacks support for 'report' mode. With this change, such files
are skipped automatically, improving robustness and developer
experience.
Signed-off-by: Songwei Chai <quic_songchai@quicinc.com>
Reviewed-by: Julia Lawall <Julia.Lawall@inria.fr>
- Disable link power management (LPM) for a Seagate drive that is
misbehaving when LPM is enabled.
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Merge tag 'ata-6.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux
Pull ata fix from Damien Le Moal:
- Disable link power management (LPM) for a Seagate drive that is
misbehaving when LPM is enabled
* tag 'ata-6.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: libata-core: Disable LPM on ST2000DM008-2FR102
A small collection of fixes for various SPI drivers, plus a relaxation
of constraints in the DT for the DesignWare controller to reflect
hardware that's been seen. There's several fixes for the Cadence
QuadSPI driver since a fix during the last release made some existing
issues with error handling during probe more readily visible.
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Merge tag 'spi-fix-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A small collection of fixes for various SPI drivers, plus a relaxation
of constraints in the DT for the DesignWare controller to reflect
hardware that's been seen.
There's several fixes for the Cadence QuadSPI driver since a fix
during the last release made some existing issues with error handling
during probe more readily visible"
* tag 'spi-fix-v6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: mt65xx: Use IRQF_ONESHOT with threaded IRQ
spi: dt-bindings: snps,dw-abp-ssi: Allow up to 16 chip-selects
spi: cadence-quadspi: Fix clock disable on probe failure path
spi: cadence-quadspi: Add error logging for DMA request failure
spi: fsl-cpm: Check length parity before switching to 16 bit mode
spi: mpfs: Fix an error handling path in mpfs_spi_probe()
clang is generating very inefficient code for native_save_fl() which is
used for local_irq_save() in critical spots.
Allowing the "pop %0" to use memory:
1) forces the compiler to add annoying stack canaries when
CONFIG_STACKPROTECTOR_STRONG=y in many places.
2) Almost always is followed by an immediate "move memory,register"
One good example is _raw_spin_lock_irqsave, with 8 extra instructions
ffffffff82067a30 <_raw_spin_lock_irqsave>:
ffffffff82067a30: ...
ffffffff82067a39: 53 push %rbx
// Three instructions to ajust the stack, read the per-cpu canary
// and copy it to 8(%rsp)
ffffffff82067a3a: 48 83 ec 10 sub $0x10,%rsp
ffffffff82067a3e: 65 48 8b 05 da 15 45 02 mov %gs:0x24515da(%rip),%rax # <__stack_chk_guard>
ffffffff82067a46: 48 89 44 24 08 mov %rax,0x8(%rsp)
ffffffff82067a4b: 9c pushf
// instead of pop %rbx, compiler uses 2 instructions.
ffffffff82067a4c: 8f 04 24 pop (%rsp)
ffffffff82067a4f: 48 8b 1c 24 mov (%rsp),%rbx
ffffffff82067a53: fa cli
ffffffff82067a54: b9 01 00 00 00 mov $0x1,%ecx
ffffffff82067a59: 31 c0 xor %eax,%eax
ffffffff82067a5b: f0 0f b1 0f lock cmpxchg %ecx,(%rdi)
ffffffff82067a5f: 75 1d jne ffffffff82067a7e <_raw_spin_lock_irqsave+0x4e>
// three instructions to check the stack canary
ffffffff82067a61: 65 48 8b 05 b7 15 45 02 mov %gs:0x24515b7(%rip),%rax # <__stack_chk_guard>
ffffffff82067a69: 48 3b 44 24 08 cmp 0x8(%rsp),%rax
ffffffff82067a6e: 75 17 jne ffffffff82067a87
...
// One extra instruction to adjust the stack.
ffffffff82067a73: 48 83 c4 10 add $0x10,%rsp
...
// One more instruction in case the stack was mangled.
ffffffff82067a87: e8 a4 35 ff ff call ffffffff8205b030 <__stack_chk_fail>
This patch changes nothing for gcc, but for clang saves ~20000 bytes of text
even though more functions are inlined.
$ size vmlinux.gcc.before vmlinux.gcc.after vmlinux.clang.before vmlinux.clang.after
text data bss dec hex filename
45565821 25005462 4704800 75276083 47c9f33 vmlinux.gcc.before
45565821 25005462 4704800 75276083 47c9f33 vmlinux.gcc.after
45121072 24638617 5533040 75292729 47ce039 vmlinux.clang.before
45093887 24638633 5536808 75269328 47c84d0 vmlinux.clang.after
$ scripts/bloat-o-meter -t vmlinux.clang.before vmlinux.clang.after
add/remove: 1/2 grow/shrink: 21/533 up/down: 2250/-22112 (-19862)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Work around clang problems with "=rm" asm constraint.
clang seems to always chose the memory output, while it is almost
always the worst choice.
Add ASM_OUTPUT_RM so that we can replace "=rm" constraint
where it matters for clang, while not penalizing gcc.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
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Merge tag 'xfs-fixes-6.19-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Carlos Maiolino:
"This contains a few fixes for zoned devices support, an UAF and a
compiler warning, and some cleaning up"
* tag 'xfs-fixes-6.19-rc2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix the zoned RT growfs check for zone alignment
xfs: validate that zoned RT devices are zone aligned
xfs: fix XFS_ERRTAG_FORCE_ZERO_RANGE for zoned file system
xfs: fix a memory leak in xfs_buf_item_init()
xfs: fix stupid compiler warning
xfs: fix a UAF problem in xattr repair
xfs: ignore discard return value
