1. 01 Dec, 2022 6 commits
    • Robert Marko's avatar
      clk: qcom: ipq8074: add missing networking resets · ce520e31
      Robert Marko authored
      Downstream QCA 5.4 kernel defines networking resets which are not present
      in the mainline kernel but are required for the networking drivers.
      
      So, port the downstream resets and avoid using magic values for mask,
      construct mask for resets which require multiple bits to be set/cleared.
      Signed-off-by: default avatarRobert Marko <robimarko@gmail.com>
      Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
      Link: https://lore.kernel.org/r/20221107132901.489240-3-robimarko@gmail.com
      ce520e31
    • Robert Marko's avatar
      bb524058
    • Robert Marko's avatar
      clk: qcom: reset: support resetting multiple bits · 4a521089
      Robert Marko authored
      This patch adds the support for giving the complete bitmask
      in reset structure and reset operation will use this bitmask
      for all reset operations.
      
      Currently, reset structure only takes a single bit for each reset
      and then calculates the bitmask by using the BIT() macro.
      
      However, this is not sufficient anymore for newer SoC-s like IPQ8074,
      IPQ6018 and more, since their networking resets require multiple bits
      to be asserted in order to properly reset the HW block completely.
      
      So, in order to allow asserting multiple bits add "bitmask" field to
      qcom_reset_map, and then use that bitmask value if its populated in the
      driver, if its not populated, then we just default to existing behaviour
      and calculate the bitmask on the fly.
      Signed-off-by: default avatarRobert Marko <robimarko@gmail.com>
      Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
      Link: https://lore.kernel.org/r/20221107132901.489240-1-robimarko@gmail.com
      4a521089
    • Douglas Anderson's avatar
      clk: qcom: lpass-sc7180: Avoid an extra "struct dev_pm_ops" · e3ad6c3f
      Douglas Anderson authored
      The two devices managed by lpasscorecc-sc7180.c each had their own
      "struct dev_pm_ops". This is not needed. They are exactly the same and
      the structure is "static const" so it can't possible change. combine
      the two. This matches what's done for sc7280.
      
      This should be a noop other than saving a few bytes.
      Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
      Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
      Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
      Link: https://lore.kernel.org/r/20221104064055.3.I90ba14a47683a484f26531a08f7b46ace7f0a8a9@changeid
      e3ad6c3f
    • Douglas Anderson's avatar
      clk: qcom: lpass-sc7180: Fix pm_runtime usage · ff1ccf59
      Douglas Anderson authored
      The sc7180 lpass clock controller's pm_runtime usage wasn't broken
      quite as spectacularly as the sc7280's pm_runtime usage, but it was
      still broken. Putting some printouts in at boot showed me this (with
      serial console enabled, which makes the prints slow and thus changes
      timing):
        [    3.109951] DOUG: my_pm_clk_resume, usage=1
        [    3.114767] DOUG: my_pm_clk_resume, usage=1
        [    3.664443] DOUG: my_pm_clk_suspend, usage=0
        [    3.897566] DOUG: my_pm_clk_suspend, usage=0
        [    3.910137] DOUG: my_pm_clk_resume, usage=1
        [    3.923217] DOUG: my_pm_clk_resume, usage=0
        [    4.440116] DOUG: my_pm_clk_suspend, usage=-1
        [    4.444982] DOUG: my_pm_clk_suspend, usage=0
        [   14.170501] DOUG: my_pm_clk_resume, usage=1
        [   14.176245] DOUG: my_pm_clk_resume, usage=0
      
      ...or this w/out serial console:
        [    0.556139] DOUG: my_pm_clk_resume, usage=1
        [    0.556279] DOUG: my_pm_clk_resume, usage=1
        [    1.058422] DOUG: my_pm_clk_suspend, usage=-1
        [    1.058464] DOUG: my_pm_clk_suspend, usage=0
        [    1.186250] DOUG: my_pm_clk_resume, usage=1
        [    1.186292] DOUG: my_pm_clk_resume, usage=0
        [    1.731536] DOUG: my_pm_clk_suspend, usage=-1
        [    1.731557] DOUG: my_pm_clk_suspend, usage=0
        [   10.288910] DOUG: my_pm_clk_resume, usage=1
        [   10.289496] DOUG: my_pm_clk_resume, usage=0
      
      It seems to be doing roughly the right sequence of calls, but just
      like with sc7280 this is more by luck than anything. Having a usage of
      -1 is just not OK.
      
      Let's fix this like we did with sc7280.
      Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
      Fixes: ce8c195e ("clk: qcom: lpasscc: Introduce pm autosuspend for SC7180")
      Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
      Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
      Link: https://lore.kernel.org/r/20221104064055.2.I49b25b9bda9430fc7ea21e5a708ca5a0aced2798@changeid
      ff1ccf59
    • Douglas Anderson's avatar
      clk: qcom: lpass-sc7280: Fix pm_runtime usage · d470be3c
      Douglas Anderson authored
      The pm_runtime usage in lpass-sc7280 was broken in quite a few
      ways. Specifically:
      
      1. At the end of probe it called "put" twice. This is a no-no and will
         end us up with a negative usage count. Even worse than calling
         "put" twice, it never called "get" once. Thus after bootup it could
         be seen that the runtime usage of the devices managed by this
         driver was -2.
      2. In some error cases it manually called pm_runtime_disable() even
         though it had previously used devm_add_action_or_reset() to set
         this up to be called automatically. This meant that in these error
         cases we'd double-call pm_runtime_disable().
      3. It forgot to call undo pm_runtime_use_autosuspend(), which can
         sometimes have subtle problems (and the docs specifically mention
         that you need to undo this function).
      
      Overall the above seriously calls into question how this driver is
      working. It seems like a combination of "it doesn't", "by luck", and
      "because of the weirdness of runtime_pm". Specifically I put a
      printout to the serial console every time the runtime suspend/resume
      was called for the two devices created by this driver (I wrapped the
      pm_clk calls). When I had serial console enabled, I found that the
      calls got resumed at bootup (when the clk core probed and before our
      double-put) and then never touched again. That's no good.
        [    0.829997] DOUG: my_pm_clk_resume, usage=1
        [    0.835487] DOUG: my_pm_clk_resume, usage=1
      
      When I disabled serial console (speeding up boot), I got a different
      pattern, which I guess (?) is better:
        [    0.089767] DOUG: my_pm_clk_resume, usage=1
        [    0.090507] DOUG: my_pm_clk_resume, usage=1
        [    0.151885] DOUG: my_pm_clk_suspend, usage=-2
        [    0.151914] DOUG: my_pm_clk_suspend, usage=-2
        [    1.825747] DOUG: my_pm_clk_resume, usage=-1
        [    1.825774] DOUG: my_pm_clk_resume, usage=-1
        [    1.888269] DOUG: my_pm_clk_suspend, usage=-2
        [    1.888282] DOUG: my_pm_clk_suspend, usage=-2
      
      These different patterns have to do with the fact that the core PM
      Runtime code really isn't designed to be robust to negative usage
      counts and sometimes may happen to stumble upon a behavior that
      happens to "work". For instance, you can see that
      __pm_runtime_suspend() will treat any non-zero value (including
      negative numbers) as if the device is in use.
      
      In any case, let's fix the driver to be correct. We'll hold a
      pm_runtime reference for the whole probe and then drop it (once!) at
      the end. We'll get rid of manual pm_runtime_disable() calls in the
      error handling. We'll also switch to devm_pm_runtime_enable(), which
      magically handles undoing pm_runtime_use_autosuspend() as of commit
      b4060db9 ("PM: runtime: Have devm_pm_runtime_enable() handle
      pm_runtime_dont_use_autosuspend()").
      
      While we're at this, let's also use devm_pm_clk_create() instead of
      rolling it ourselves.
      
      Note that the above changes make it obvious that
      lpassaudio_create_pm_clks() was doing more than just creating
      clocks. It was also setting up pm_runtime parameters. Let's rename it.
      
      All of these problems were found by code inspection. I started looking
      at this driver because it was involved in a deadlock that I reported a
      while ago [1]. Though I bisected the deadlock to commit 1b771839
      ("clk: qcom: gdsc: enable optional power domain support"), it was
      never really clear why that patch affected it other than a luck of
      timing changes. I'll also note that by fixing the timing (as done in
      this change) we also seem to aboid the deadlock, which is a nice
      benefit.
      
      Also note that some of the fixes here are much the same type of stuff
      that Dmitry did in commit 72cfc73f ("clk: qcom: use
      devm_pm_runtime_enable and devm_pm_clk_create"), but I guess
      lpassaudiocc-sc7280.c didn't exist then.
      
      [1] https://lore.kernel.org/r/20220922154354.2486595-1-dianders@chromium.org
      
      Fixes: a9dd2663 ("clk: qcom: lpass: Add support for LPASS clock controller for SC7280")
      Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
      Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
      Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
      Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
      Link: https://lore.kernel.org/r/20221104064055.1.I00a0e4564a25489e85328ec41636497775627564@changeid
      d470be3c
  2. 15 Nov, 2022 2 commits
  3. 10 Nov, 2022 2 commits
  4. 08 Nov, 2022 2 commits
  5. 07 Nov, 2022 4 commits
  6. 06 Nov, 2022 15 commits
  7. 17 Oct, 2022 1 commit
  8. 16 Oct, 2022 8 commits
    • Linus Torvalds's avatar
      Linux 6.1-rc1 · 9abf2313
      Linus Torvalds authored
      9abf2313
    • Linus Torvalds's avatar
      Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random · f1947d7c
      Linus Torvalds authored
      Pull more random number generator updates from Jason Donenfeld:
       "This time with some large scale treewide cleanups.
      
        The intent of this pull is to clean up the way callers fetch random
        integers. The current rules for doing this right are:
      
         - If you want a secure or an insecure random u64, use get_random_u64()
      
         - If you want a secure or an insecure random u32, use get_random_u32()
      
           The old function prandom_u32() has been deprecated for a while
           now and is just a wrapper around get_random_u32(). Same for
           get_random_int().
      
         - If you want a secure or an insecure random u16, use get_random_u16()
      
         - If you want a secure or an insecure random u8, use get_random_u8()
      
         - If you want secure or insecure random bytes, use get_random_bytes().
      
           The old function prandom_bytes() has been deprecated for a while
           now and has long been a wrapper around get_random_bytes()
      
         - If you want a non-uniform random u32, u16, or u8 bounded by a
           certain open interval maximum, use prandom_u32_max()
      
           I say "non-uniform", because it doesn't do any rejection sampling
           or divisions. Hence, it stays within the prandom_*() namespace, not
           the get_random_*() namespace.
      
           I'm currently investigating a "uniform" function for 6.2. We'll see
           what comes of that.
      
        By applying these rules uniformly, we get several benefits:
      
         - By using prandom_u32_max() with an upper-bound that the compiler
           can prove at compile-time is ≤65536 or ≤256, internally
           get_random_u16() or get_random_u8() is used, which wastes fewer
           batched random bytes, and hence has higher throughput.
      
         - By using prandom_u32_max() instead of %, when the upper-bound is
           not a constant, division is still avoided, because
           prandom_u32_max() uses a faster multiplication-based trick instead.
      
         - By using get_random_u16() or get_random_u8() in cases where the
           return value is intended to indeed be a u16 or a u8, we waste fewer
           batched random bytes, and hence have higher throughput.
      
        This series was originally done by hand while I was on an airplane
        without Internet. Later, Kees and I worked on retroactively figuring
        out what could be done with Coccinelle and what had to be done
        manually, and then we split things up based on that.
      
        So while this touches a lot of files, the actual amount of code that's
        hand fiddled is comfortably small"
      
      * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
        prandom: remove unused functions
        treewide: use get_random_bytes() when possible
        treewide: use get_random_u32() when possible
        treewide: use get_random_{u8,u16}() when possible, part 2
        treewide: use get_random_{u8,u16}() when possible, part 1
        treewide: use prandom_u32_max() when possible, part 2
        treewide: use prandom_u32_max() when possible, part 1
      f1947d7c
    • Linus Torvalds's avatar
      Merge tag 'perf-tools-for-v6.1-2-2022-10-16' of... · 8636df94
      Linus Torvalds authored
      Merge tag 'perf-tools-for-v6.1-2-2022-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
      
      Pull more perf tools updates from Arnaldo Carvalho de Melo:
      
       - Use BPF CO-RE (Compile Once, Run Everywhere) to support old kernels
         when using bperf (perf BPF based counters) with cgroups.
      
       - Support HiSilicon PCIe Performance Monitoring Unit (PMU), that
         monitors bandwidth, latency, bus utilization and buffer occupancy.
      
         Documented in Documentation/admin-guide/perf/hisi-pcie-pmu.rst.
      
       - User space tasks can migrate between CPUs, so when tracing selected
         CPUs, system-wide sideband is still needed, fix it in the setup of
         Intel PT on hybrid systems.
      
       - Fix metricgroups title message in 'perf list', it should state that
         the metrics groups are to be used with the '-M' option, not '-e'.
      
       - Sync the msr-index.h copy with the kernel sources, adding support for
         using "AMD64_TSC_RATIO" in filter expressions in 'perf trace' as well
         as decoding it when printing the MSR tracepoint arguments.
      
       - Fix program header size and alignment when generating a JIT ELF in
         'perf inject'.
      
       - Add multiple new Intel PT 'perf test' entries, including a jitdump
         one.
      
       - Fix the 'perf test' entries for 'perf stat' CSV and JSON output when
         running on PowerPC due to an invalid topology number in that arch.
      
       - Fix the 'perf test' for arm_coresight failures on the ARM Juno
         system.
      
       - Fix the 'perf test' attr entry for PERF_FORMAT_LOST, adding this
         option to the or expression expected in the intercepted
         perf_event_open() syscall.
      
       - Add missing condition flags ('hs', 'lo', 'vc', 'vs') for arm64 in the
         'perf annotate' asm parser.
      
       - Fix 'perf mem record -C' option processing, it was being chopped up
         when preparing the underlying 'perf record -e mem-events' and thus
         being ignored, requiring using '-- -C CPUs' as a workaround.
      
       - Improvements and tidy ups for 'perf test' shell infra.
      
       - Fix Intel PT information printing segfault in uClibc, where a NULL
         format was being passed to fprintf.
      
      * tag 'perf-tools-for-v6.1-2-2022-10-16' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (23 commits)
        tools arch x86: Sync the msr-index.h copy with the kernel sources
        perf auxtrace arm64: Add support for parsing HiSilicon PCIe Trace packet
        perf auxtrace arm64: Add support for HiSilicon PCIe Tune and Trace device driver
        perf auxtrace arm: Refactor event list iteration in auxtrace_record__init()
        perf tests stat+json_output: Include sanity check for topology
        perf tests stat+csv_output: Include sanity check for topology
        perf intel-pt: Fix system_wide dummy event for hybrid
        perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc
        perf test: Fix attr tests for PERF_FORMAT_LOST
        perf test: test_intel_pt.sh: Add 9 tests
        perf inject: Fix GEN_ELF_TEXT_OFFSET for jit
        perf test: test_intel_pt.sh: Add jitdump test
        perf test: test_intel_pt.sh: Tidy some alignment
        perf test: test_intel_pt.sh: Print a message when skipping kernel tracing
        perf test: test_intel_pt.sh: Tidy some perf record options
        perf test: test_intel_pt.sh: Fix return checking again
        perf: Skip and warn on unknown format 'configN' attrs
        perf list: Fix metricgroups title message
        perf mem: Fix -C option behavior for perf mem record
        perf annotate: Add missing condition flags for arm64
        ...
      8636df94
    • Linus Torvalds's avatar
      Merge tag 'kbuild-fixes-v6.1' of... · 2df76606
      Linus Torvalds authored
      Merge tag 'kbuild-fixes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
      
      Pull Kbuild fixes from Masahiro Yamada:
      
       - Fix CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y compile error for the
         combination of Clang >= 14 and GAS <= 2.35.
      
       - Drop vmlinux.bz2 from the rpm package as it just annoyingly increased
         the package size.
      
       - Fix modpost error under build environments using musl.
      
       - Make *.ll files keep value names for easier debugging
      
       - Fix single directory build
      
       - Prevent RISC-V from selecting the broken DWARF5 support when Clang
         and GAS are used together.
      
      * tag 'kbuild-fixes-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
        lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5
        kbuild: fix single directory build
        kbuild: add -fno-discard-value-names to cmd_cc_ll_c
        scripts/clang-tools: Convert clang-tidy args to list
        modpost: put modpost options before argument
        kbuild: Stop including vmlinux.bz2 in the rpm's
        Kconfig.debug: add toolchain checks for DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
        Kconfig.debug: simplify the dependency of DEBUG_INFO_DWARF4/5
      2df76606
    • Linus Torvalds's avatar
      Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux · 2fcd8f10
      Linus Torvalds authored
      Pull more clk updates from Stephen Boyd:
       "This is the final part of the clk patches for this merge window.
      
        The clk rate range series needed another week to fully bake. Maxime
        fixed the bug that broke clk notifiers and prevented this from being
        included in the first pull request. He also added a unit test on top
        to make sure it doesn't break so easily again. The majority of the
        series fixes up how the clk_set_rate_*() APIs work, particularly
        around when the rate constraints are dropped and how they move around
        when reparenting clks. Overall it's a much needed improvement to the
        clk rate range APIs that used to be pretty broken if you looked
        sideways.
      
        Beyond the core changes there are a few driver fixes for a compilation
        issue or improper data causing clks to fail to register or have the
        wrong parents. These are good to get in before the first -rc so that
        the system actually boots on the affected devices"
      
      * tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (31 commits)
        clk: tegra: Fix Tegra PWM parent clock
        clk: at91: fix the build with binutils 2.27
        clk: qcom: gcc-msm8660: Drop hardcoded fixed board clocks
        clk: mediatek: clk-mux: Add .determine_rate() callback
        clk: tests: Add tests for notifiers
        clk: Update req_rate on __clk_recalc_rates()
        clk: tests: Add missing test case for ranges
        clk: qcom: clk-rcg2: Take clock boundaries into consideration for gfx3d
        clk: Introduce the clk_hw_get_rate_range function
        clk: Zero the clk_rate_request structure
        clk: Stop forwarding clk_rate_requests to the parent
        clk: Constify clk_has_parent()
        clk: Introduce clk_core_has_parent()
        clk: Switch from __clk_determine_rate to clk_core_round_rate_nolock
        clk: Add our request boundaries in clk_core_init_rate_req
        clk: Introduce clk_hw_init_rate_request()
        clk: Move clk_core_init_rate_req() from clk_core_round_rate_nolock() to its caller
        clk: Change clk_core_init_rate_req prototype
        clk: Set req_rate on reparenting
        clk: Take into account uncached clocks in clk_set_rate_range()
        ...
      2fcd8f10
    • Linus Torvalds's avatar
      Merge tag '6.1-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6 · b08cd744
      Linus Torvalds authored
      Pull more cifs updates from Steve French:
      
       - fix a regression in guest mounts to old servers
      
       - improvements to directory leasing (caching directory entries safely
         beyond the root directory)
      
       - symlink improvement (reducing roundtrips needed to process symlinks)
      
       - an lseek fix (to problem where some dir entries could be skipped)
      
       - improved ioctl for returning more detailed information on directory
         change notifications
      
       - clarify multichannel interface query warning
      
       - cleanup fix (for better aligning buffers using ALIGN and round_up)
      
       - a compounding fix
      
       - fix some uninitialized variable bugs found by Coverity and the kernel
         test robot
      
      * tag '6.1-rc-smb3-client-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
        smb3: improve SMB3 change notification support
        cifs: lease key is uninitialized in two additional functions when smb1
        cifs: lease key is uninitialized in smb1 paths
        smb3: must initialize two ACL struct fields to zero
        cifs: fix double-fault crash during ntlmssp
        cifs: fix static checker warning
        cifs: use ALIGN() and round_up() macros
        cifs: find and use the dentry for cached non-root directories also
        cifs: enable caching of directories for which a lease is held
        cifs: prevent copying past input buffer boundaries
        cifs: fix uninitialised var in smb2_compound_op()
        cifs: improve symlink handling for smb2+
        smb3: clarify multichannel warning
        cifs: fix regression in very old smb1 mounts
        cifs: fix skipping to incorrect offset in emit_cached_dirents
      b08cd744
    • Tetsuo Handa's avatar
      Revert "cpumask: fix checking valid cpu range". · 80493877
      Tetsuo Handa authored
      This reverts commit 78e5a339 ("cpumask: fix checking valid cpu range").
      
      syzbot is hitting WARN_ON_ONCE(cpu >= nr_cpumask_bits) warning at
      cpu_max_bits_warn() [1], for commit 78e5a339 ("cpumask: fix checking
      valid cpu range") is broken.  Obviously that patch hits WARN_ON_ONCE()
      when e.g.  reading /proc/cpuinfo because passing "cpu + 1" instead of
      "cpu" will trivially hit cpu == nr_cpumask_bits condition.
      
      Although syzbot found this problem in linux-next.git on 2022/09/27 [2],
      this problem was not fixed immediately.  As a result, that patch was
      sent to linux.git before the patch author recognizes this problem, and
      syzbot started failing to test changes in linux.git since 2022/10/10
      [3].
      
      Andrew Jones proposed a fix for x86 and riscv architectures [4].  But
      [2] and [5] indicate that affected locations are not limited to arch
      code.  More delay before we find and fix affected locations, less tested
      kernel (and more difficult to bisect and fix) before release.
      
      We should have inspected and fixed basically all cpumask users before
      applying that patch.  We should not crash kernels in order to ask
      existing cpumask users to update their code, even if limited to
      CONFIG_DEBUG_PER_CPU_MAPS=y case.
      
      Link: https://syzkaller.appspot.com/bug?extid=d0fd2bf0dd6da72496dd [1]
      Link: https://syzkaller.appspot.com/bug?extid=21da700f3c9f0bc40150 [2]
      Link: https://syzkaller.appspot.com/bug?extid=51a652e2d24d53e75734 [3]
      Link: https://lkml.kernel.org/r/20221014155845.1986223-1-ajones@ventanamicro.com [4]
      Link: https://syzkaller.appspot.com/bug?extid=4d46c43d81c3bd155060 [5]
      Reported-by: default avatarAndrew Jones <ajones@ventanamicro.com>
      Reported-by: syzbot+d0fd2bf0dd6da72496dd@syzkaller.appspotmail.com
      Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Cc: Yury Norov <yury.norov@gmail.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      80493877
    • Nathan Chancellor's avatar
      lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5 · 0a6de78c
      Nathan Chancellor authored
      When building with a RISC-V kernel with DWARF5 debug info using clang
      and the GNU assembler, several instances of the following error appear:
      
        /tmp/vgettimeofday-48aa35.s:2963: Error: non-constant .uleb128 is not supported
      
      Dumping the .s file reveals these .uleb128 directives come from
      .debug_loc and .debug_ranges:
      
        .Ldebug_loc0:
                .byte   4                               # DW_LLE_offset_pair
                .uleb128 .Lfunc_begin0-.Lfunc_begin0    #   starting offset
                .uleb128 .Ltmp1-.Lfunc_begin0           #   ending offset
                .byte   1                               # Loc expr size
                .byte   90                              # DW_OP_reg10
                .byte   0                               # DW_LLE_end_of_list
      
        .Ldebug_ranges0:
                .byte   4                               # DW_RLE_offset_pair
                .uleb128 .Ltmp6-.Lfunc_begin0           #   starting offset
                .uleb128 .Ltmp27-.Lfunc_begin0          #   ending offset
                .byte   4                               # DW_RLE_offset_pair
                .uleb128 .Ltmp28-.Lfunc_begin0          #   starting offset
                .uleb128 .Ltmp30-.Lfunc_begin0          #   ending offset
                .byte   0                               # DW_RLE_end_of_list
      
      There is an outstanding binutils issue to support a non-constant operand
      to .sleb128 and .uleb128 in GAS for RISC-V but there does not appear to
      be any movement on it, due to concerns over how it would work with
      linker relaxation.
      
      To avoid these build errors, prevent DWARF5 from being selected when
      using clang and an assembler that does not have support for these symbol
      deltas, which can be easily checked in Kconfig with as-instr plus the
      small test program from the dwz test suite from the binutils issue.
      
      Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
      Link: https://github.com/ClangBuiltLinux/linux/issues/1719Signed-off-by: default avatarNathan Chancellor <nathan@kernel.org>
      Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
      Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      0a6de78c