Replace the unconditional clflush() with drm_clflush_virt_range()
which does the wbinvd() fallback when clflush is not available.
This time no justification is given for the clflush in the
offending commit.
Cc: stable@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Fixes: 2c8ab3339e ("drm/i915: Pin timeline map after first timeline pin, v4.")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014090941.12159-4-ville.syrjala@linux.intel.com
Reviewed-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit 9ced12182d)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This one is apparently a "clflush for good measure", so bit more
justification (if you can call it that) than some of the others.
Convert to drm_clflush_virt_range() again so that machines without
clflush will survive the ordeal.
Cc: stable@vger.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellström <thomas.hellstrom@intel.com> #v1
Fixes: 12ca695d2c ("drm/i915: Do not share hwsp across contexts any more, v8.")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014090941.12159-3-ville.syrjala@linux.intel.com
Reviewed-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit af7b6d234e)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
It can be compatible with exynos850's chipid. The SoC has eight chipid
registers that can be used for OTP.
Cc: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20211021012017.158919-3-chanho61.park@samsung.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
The product id of Exynos Auto v9 is "0xAAA8_0000". Add this id and its
name.
Cc: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20211021012017.158919-2-chanho61.park@samsung.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
This reverts commit 0986d7bc55.
It still has some issues and needs to be dropped at this point in time.
Link: https://lore.kernel.org/r/208f7a41-a9fa-630c-cb44-c37c503f3a72@kernel.org
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Cc: Xianting Tian <xianting.tian@linux.alibaba.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 9db81eca10.
A dependant patch on this one needs to be reverted, so this one also
needs to be reverted at this point in time.
Link: https://lore.kernel.org/r/208f7a41-a9fa-630c-cb44-c37c503f3a72@kernel.org
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Cc: Xianting Tian <xianting.tian@linux.alibaba.com>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'else' keyword is not needed when previous conditional branch returns
to the upper layer. Get rid of redundant 'else' keyword in such cases.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jiri Slaby <jslaby@kernel.org>
Link: https://lore.kernel.org/r/20211022135147.70965-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The loop can be refactored by using ARRAY_SIZE() instead of NULL terminator.
This reduces code base and makes it easier to read and understand.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jiri Slaby <jslaby@kernel.org>
Link: https://lore.kernel.org/r/20211022135147.70965-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB control and bulk message timeouts are specified in milliseconds and
should specifically not vary with CONFIG_HZ.
Fixes: c6d43ba816 ("ALSA: usb/6fire - Driver for TerraTec DMX 6Fire USB")
Cc: stable@vger.kernel.org # 2.6.39
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211025121142.6531-2-johan@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The pointer cs_desc return from snd_usb_find_clock_source could
be null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.
Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
Link: https://lore.kernel.org/r/20211024111736.11342-1-cyeaa@connect.ust.hk
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The pointer block return from snd_gf1_dma_next_block could be
null, so there is a potential null pointer dereference issue.
Fix this by adding a null check before dereference.
Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
Link: https://lore.kernel.org/r/20211024104611.9919-1-cyeaa@connect.ust.hk
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This removes properties not used by either the PWM or timer drivers.
This lets us set additionalProperties: false.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/20211025180605.252476-1-sean.anderson@seco.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Without CONFIG_PM_SLEEP, the runtime suspend/resume functions
are unused, producing a warning:
../drivers/dma/sa11x0-dma.c:1042:12: error: 'sa11x0_dma_resume' defined but not used
../drivers/dma/sa11x0-dma.c:1004:12: error: 'sa11x0_dma_suspend' defined but not used
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211026020508.550-1-caihuoqing@baidu.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The wrappers in include/linux/pci-dma-compat.h should go away.
pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.
Signed-off-by: Qing Wang <wangqing@vivo.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://lore.kernel.org/r/1633663733-47199-7-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The wrappers in include/linux/pci-dma-compat.h should go away.
pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.
Signed-off-by: Qing Wang <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1633663733-47199-3-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The wrappers in include/linux/pci-dma-compat.h should go away.
pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.
Signed-off-by: Qing Wang <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1633663733-47199-4-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The wrappers in include/linux/pci-dma-compat.h should go away.
pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.
Signed-off-by: Qing Wang <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1633663733-47199-5-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The wrappers in include/linux/pci-dma-compat.h should go away.
pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.
Signed-off-by: Qing Wang <wangqing@vivo.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1633663733-47199-6-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The wrappers in include/linux/pci-dma-compat.h should go away.
pci_set_dma_mask()/pci_set_consistent_dma_mask() should be
replaced with dma_set_mask()/dma_set_coherent_mask(),
and use dma_set_mask_and_coherent() for both.
Signed-off-by: Wang Qing <wangqing@vivo.com>
Link: https://lore.kernel.org/r/1633663733-47199-2-git-send-email-wangqing@vivo.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Function in modules could appear in /proc/kallsyms in random order.
ffffffffa02608a0 t bpf_testmod_loop_test
ffffffffa02600c0 t __traceiter_bpf_testmod_test_writable_bare
ffffffffa0263b60 d __tracepoint_bpf_testmod_test_write_bare
ffffffffa02608c0 T bpf_testmod_test_read
ffffffffa0260d08 t __SCT__tp_func_bpf_testmod_test_writable_bare
ffffffffa0263300 d __SCK__tp_func_bpf_testmod_test_read
ffffffffa0260680 T bpf_testmod_test_write
ffffffffa0260860 t bpf_testmod_test_mod_kfunc
Therefore, we cannot reliably use kallsyms_find_next() to find the end of
a function. Replace it with a simple guess (start + 128). This is good
enough for this test.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022234814.318457-1-songliubraving@fb.com
Skipping the second half of the test is not enough to silent the warning
in dmesg. Skip the whole test before we can either properly silent the
warning in kernel, or fix LBR snapshot for VM.
Fixes: 025bd7c753 ("selftests/bpf: Add test for bpf_get_branch_snapshot")
Fixes: aa67fdb464 ("selftests/bpf: Skip the second half of get_branch_snapshot in vm")
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026000733.477714-1-songliubraving@fb.com
Ilya Leoshkevich says:
====================
v2: https://lore.kernel.org/bpf/20211025131214.731972-1-iii@linux.ibm.com/
v2 -> v3: Split the fix from the cleanup (Daniel).
v1: https://lore.kernel.org/bpf/20211021234653.643302-1-iii@linux.ibm.com/
v1 -> v2: Drop bpf_core_calc_field_relo() restructuring, split the
__BYTE_ORDER__ change (Andrii).
Hi,
this series fixes test failures in core_reloc on s390.
Patch 1 fixes an endianness bug with __BYTE_ORDER vs __BYTE_ORDER__.
Patches 2-5 make the rest of the code consistent in that respect.
Patch 6 fixes an endianness issue in test_core_reloc_mods.
Best regards,
Ilya
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-6-iii@linux.ibm.com
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-5-iii@linux.ibm.com
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-4-iii@linux.ibm.com
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-3-iii@linux.ibm.com
__BYTE_ORDER is supposed to be defined by a libc, and __BYTE_ORDER__ -
by a compiler. bpf_core_read.h checks __BYTE_ORDER == __LITTLE_ENDIAN,
which is true if neither are defined, leading to incorrect behavior on
big-endian hosts if libc headers are not included, which is often the
case.
Fixes: ee26dade0e ("libbpf: Add support for relocatable bitfields")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-2-iii@linux.ibm.com
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing
output," the migrate disabled field is also printed in the !PREEMPR_RT
kernel config. While this information was added to the vast majority of
tracers, osnoise and timerlat were not updated (because they are new
tracers).
Fix timerlat header by adding the information about migrate disabled.
Link: https://lkml.kernel.org/r/bc0c234ab49946cdd63effa6584e1d5e8662cb44.1634308385.git.bristot@kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes: 54357f0c91 ("tracing: Add migrate-disabled counter to tracing output.")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Since "54357f0c9149 tracing: Add migrate-disabled counter to tracing
output," the migrate disabled field is also printed in the !PREEMPR_RT
kernel config. While this information was added to the vast majority of
tracers, osnoise and timerlat were not updated (because they are new
tracers).
Fix osnoise header by adding the information about migrate disabled.
Link: https://lkml.kernel.org/r/9cb3d54e29e0588dbba12e81486bd8a09adcd8ca.1634308385.git.bristot@kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Fixes: 54357f0c91 ("tracing: Add migrate-disabled counter to tracing output.")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
s/CONFIG_OSNOISE_TRAECR/CONFIG_OSNOISE_TRACER/
No functional changes.
Link: https://lkml.kernel.org/r/33924a16f6e5559ce24952ca7d62561604bfd94a.1634308385.git.bristot@kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
It is useful to trace functions in kernel/event/core.c. Allow ftrace for
them by removing $(CC_FLAGS_FTRACE) from Makefile.
Link: https://lkml.kernel.org/r/20211006210732.2826289-1-songliubraving@fb.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: KP Singh <kpsingh@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This symbol is not used outside of ftrace.c, so marks it static.
Fixes the following sparse warning:
kernel/trace/ftrace.c:579:5: warning: symbol 'ftrace_profile_pages_init'
was not declared. Should it be static?
Link: https://lkml.kernel.org/r/1634640534-18280-1-git-send-email-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Fixes: cafb168a1c ("tracing: make the function profiler per cpu")
Signed-off-by: chongjiapeng <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Jean Sacren says:
====================
Small fixes for true expression checks
This series fixes checks of true !rc expression.
====================
Link: https://lore.kernel.org/r/cover.1634974124.git.sakiwit@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Remove the check of !rc in (!rc && !resc_lock_params.b_granted) since it
is always true.
Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Remove the check of !rc in (!rc && !params.b_granted) since it is always
true.
We should also use constant 0 for return.
Signed-off-by: Jean Sacren <sakiwit@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In commit c46ed2281b ("tpm_tis_spi: add missing SPI device ID entries")
we added SPI IDs for all the DT aliases to handle the fact that we always
use SPI modaliases to load modules even when probed via DT however the
mentioned commit missed that the SPI and OF device ID entries did not
match and were different and so DT nodes with compatible
"tcg,tpm_tis-spi" will not match. Add an extra ID for tpm_tis-spi
rather than just fix the existing one since what's currently there is
going to be better for anyone actually using SPI IDs to instantiate.
Fixes: c46ed2281b ("tpm_tis_spi: add missing SPI device ID entries")
Fixes: 96c8395e21 ("spi: Revert modalias changes")
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
The Atmel TPM 1.2 chips crash with error
`tpm_try_transmit: send(): error -62` since kernel 4.14.
It is observed from the kernel log after running `tpm_sealdata -z`.
The error thrown from the command is as follows
```
$ tpm_sealdata -z
Tspi_Key_LoadKey failed: 0x00001087 - layer=tddl,
code=0087 (135), I/O error
```
The issue was reproduced with the following Atmel TPM chip:
```
$ tpm_version
T0 TPM 1.2 Version Info:
Chip Version: 1.2.66.1
Spec Level: 2
Errata Revision: 3
TPM Vendor ID: ATML
TPM Version: 01010000
Manufacturer Info: 41544d4c
```
The root cause of the issue is due to the TPM calls to msleep()
were replaced with usleep_range() [1], which reduces
the actual timeout. Via experiments, it is observed that
the original msleep(5) actually sleeps for 15ms.
Because of a known timeout issue in Atmel TPM 1.2 chip,
the shorter timeout than 15ms can cause the error described above.
A few further changes in kernel 4.16 [2] and 4.18 [3, 4] further
reduced the timeout to less than 1ms. With experiments,
the problematic timeout in the latest kernel is the one
for `wait_for_tpm_stat`.
To fix it, the patch reverts the timeout of `wait_for_tpm_stat`
to 15ms for all Atmel TPM 1.2 chips, but leave it untouched
for Ateml TPM 2.0 chip, and chips from other vendors.
As explained above, the chosen 15ms timeout is
the actual timeout before this issue introduced,
thus the old value is used here.
Particularly, TPM_ATML_TIMEOUT_WAIT_STAT_MIN is set to 14700us,
TPM_ATML_TIMEOUT_WAIT_STAT_MIN is set to 15000us according to
the existing TPM_TIMEOUT_RANGE_US (300us).
The fixed has been tested in the system with the affected Atmel chip
with no issues observed after boot up.
References:
[1] 9f3fc7bcdd tpm: replace msleep() with usleep_range() in TPM
1.2/2.0 generic drivers
[2] cf151a9a44 tpm: reduce tpm polling delay in tpm_tis_core
[3] 59f5a6b07f tpm: reduce poll sleep time in tpm_transmit()
[4] 424eaf910c tpm: reduce polling time to usecs for even finer
granularity
Fixes: 9f3fc7bcdd ("tpm: replace msleep() with usleep_range() in TPM 1.2/2.0 generic drivers")
Link: https://patchwork.kernel.org/project/linux-integrity/patch/20200926223150.109645-1-hao.wu@rubrik.com/
Signed-off-by: Hao Wu <hao.wu@rubrik.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
The "4 * be32_to_cpu(data->count)" multiplication can potentially
overflow which would lead to memory corruption. Add a check for that.
Cc: stable@vger.kernel.org
Fixes: 745b361e98 ("tpm: infrastructure for TPM spaces")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
COMPILE_TEST is helpful to find compilation errors in other platform(e.g.X86).
In this case, the support of COMPILE_TEST is added, so this module could
be compiled in other platform(e.g.X86), without ARCH_SYNQUACER configuration.
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Andrii Nakryiko says:
====================
Add libbpf APIs to access BPF program instructions. Both before and after
libbpf processing (before and after bpf_object__load()). This allows to
inspect what's going on with BPF program assembly instructions as libbpf
performs its processing magic.
But in more practical terms, this allows to do a no-brainer BPF program
cloning, which is something you need when working with fentry/fexit BPF
programs to be able to attach the same BPF program code to multiple kernel
functions. Currently, kernel needs multiple copies of BPF programs, each
loaded with its own target BTF ID. retsnoop is one such example that
previously had to rely on bpf_program__set_prep() API to hijack program
instructions ([0] for before and after).
Speaking of bpf_program__set_prep() API and the whole concept of
multiple-instance BPF programs in libbpf, all that is scheduled for
deprecation in v0.7. It doesn't work well, it's cumbersome, and it will become
more broken as libbpf adds more functionality. So deprecate and remove it in
libbpf 1.0. It doesn't seem to be used by anyone anyways (except for that
retsnoop hack, which is now much cleaner with new APIs as can be seen in [0]).
[0] https://github.com/anakryiko/retsnoop/pull/1
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The name of the API doesn't convey clearly that this size is in number
of bytes (there needed to be a separate comment to make this clear in
libbpf.h). Further, measuring the size of BPF program in bytes is not
exactly the best fit, because BPF programs always consist of 8-byte
instructions. As such, bpf_program__insn_cnt() is a better alternative
in pretty much any imaginable case.
So schedule bpf_program__size() deprecation starting from v0.7 and it
will be removed in libbpf 1.0.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-5-andrii@kernel.org
Schedule deprecation of a set of APIs that are related to multi-instance
bpf_programs:
- bpf_program__set_prep() ([0]);
- bpf_program__{set,unset}_instance() ([1]);
- bpf_program__nth_fd().
These APIs are obscure, very niche, and don't seem to be used much in
practice. bpf_program__set_prep() is pretty useless for anything but the
simplest BPF programs, as it doesn't allow to adjust BPF program load
attributes, among other things. In short, it already bitrotted and will
bitrot some more if not removed.
With bpf_program__insns() API, which gives access to post-processed BPF
program instructions of any given entry-point BPF program, it's now
possible to do whatever necessary adjustments were possible with
set_prep() API before, but also more. Given any such use case is
automatically an advanced use case, requiring users to stick to
low-level bpf_prog_load() APIs and managing their own prog FDs is
reasonable.
[0] Closes: https://github.com/libbpf/libbpf/issues/299
[1] Closes: https://github.com/libbpf/libbpf/issues/300
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-4-andrii@kernel.org
Add APIs providing read-only access to bpf_program BPF instructions ([0]).
This is useful for diagnostics purposes, but it also allows a cleaner
support for cloning BPF programs after libbpf did all the FD resolution
and CO-RE relocations, subprog instructions appending, etc. Currently,
cloning BPF program is possible only through hijacking a half-broken
bpf_program__set_prep() API, which doesn't really work well for anything
but most primitive programs. For instance, set_prep() API doesn't allow
adjusting BPF program load parameters which are necessary for loading
fentry/fexit BPF programs (the case where BPF program cloning is
a necessity if doing some sort of mass-attachment functionality).
Given bpf_program__set_prep() API is set to be deprecated, having
a cleaner alternative is a must. libbpf internally already keeps track
of linear array of struct bpf_insn, so it's not hard to expose it. The
only gotcha is that libbpf previously freed instructions array during
bpf_object load time, which would make this API much less useful overall,
because in between bpf_object__open() and bpf_object__load() a lot of
changes to instructions are done by libbpf.
So this patch makes libbpf hold onto prog->insns array even after BPF
program loading. I think this is a small price for added functionality
and improved introspection of BPF program code.
See retsnoop PR ([1]) for how it can be used in practice and code
savings compared to relying on bpf_program__set_prep().
[0] Closes: https://github.com/libbpf/libbpf/issues/298
[1] https://github.com/anakryiko/retsnoop/pull/1
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-3-andrii@kernel.org
