Merge patch series from Nick Desaulniers to update the minimum gcc
version to 5.1.
This is some of the left-overs from the merge window that I didn't want
to deal with yesterday, so it comes in after -rc1 but was sent before.
Gcc-4.9 support has been an annoyance for some time, and with -Werror I
had the choice of applying a fairly big patch from Kees Cook to remove a
fair number of initializer warnings (still leaving some), or this patch
series from Nick that just removes the source of the problem.
The initializer cleanups might still be worth it regardless, but
honestly, I preferred just tackling the problem with gcc-4.9 head-on.
We've been more aggressiuve about no longer having to care about
compilers that were released a long time ago, and I think it's been a
good thing.
I added a couple of patches on top to sort out a few left-overs now that
we no longer support gcc-4.x.
As noted by Arnd, as a result of this minimum compiler version upgrade
we can probably change our use of '--std=gnu89' to '--std=gnu11', and
finally start using local loop declarations etc. But this series does
_not_ yet do that.
Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/
Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
* emailed patches from Nick Desaulniers <ndesaulniers@google.com>:
Drop some straggling mentions of gcc-4.9 as being stale
compiler_attributes.h: drop __has_attribute() support for gcc4
vmlinux.lds.h: remove old check for GCC 4.9
compiler-gcc.h: drop checks for older GCC versions
Makefile: drop GCC < 5 -fno-var-tracking-assignments workaround
arm64: remove GCC version check for ARCH_SUPPORTS_INT128
powerpc: remove GCC version check for UPD_CONSTR
riscv: remove Kconfig check for GCC version for ARCH_RV64I
Kconfig.debug: drop GCC 5+ version check for DWARF5
mm/ksm: remove old GCC 4.9+ check
compiler.h: drop fallback overflow checkers
Documentation: raise minimum supported version of GCC to 5.1
Fix up the admin-guide README file to the new gcc-5.1 requirement, and
remove a stale comment about gcc support for the __assume_aligned__
attribute.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that GCC 5.1 is the minimally supported default, the manual
workaround for older gcc versions not having __has_attribute() are no
longer relevant and can be removed.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit fad7cd3310 ("nbd: add the check to prevent overflow in
__nbd_ioctl()") raised an issue from the fallback helpers added in
commit f0907827a8 ("compiler.h: enable builtin overflow checkers and
add fallback code")
Specifically, the helpers for checking whether the results of a
multiplication overflowed (__unsigned_mul_overflow,
__signed_add_overflow) use the division operator when
!COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW. This is problematic for 64b
operands on 32b hosts.
Also, because the macro is type agnostic, it is very difficult to write
a similarly type generic macro that dispatches to one of:
* div64_s64
* div64_u64
* div_s64
* div_u64
Raising the minimum supported versions allows us to remove all of the
fallback helpers for !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW, instead
dispatching the compiler builtins.
arm64 has already raised the minimum supported GCC version to 5.1, do
this for all targets now. See the link below for the previous
discussion.
Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/
Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 865c50e1d2 ("x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT")
added an optimised version of __get_user_asm() for x86 using 'asm goto'.
Like the non-optimised code, the 32-bit implementation of 64-bit
get_user() expands to a pair of 32-bit accesses. Unlike the
non-optimised code, the _original_ pointer is incremented to copy the
high word instead of loading through a new pointer explicitly
constructed to point at a 32-bit type. Consequently, if the pointer
points at a 64-bit type then we end up loading the wrong data for the
upper 32-bits.
This was observed as a mount() failure in Android targeting i686 after
b0cfcdd9b9 ("d_path: make 'prepend()' fill up the buffer exactly on
overflow") because the call to copy_from_kernel_nofault() from
prepend_copy() ends up in __get_kernel_nofault() and casts the source
pointer to a 'u64 __user *'. An attempt to mount at "/debug_ramdisk"
therefore ends up failing trying to mount "/debumdismdisk".
Use the existing '__gu_ptr' source pointer to unsigned int for 32-bit
__get_user_asm_u64() instead of the original pointer.
Cc: Bill Wendling <morbo@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 865c50e1d2 ("x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more perf tools updates from Arnaldo Carvalho de Melo:
- Add missing fields and remove some duplicate fields when printing a
perf_event_attr.
- Fix hybrid config terms list corruption.
- Update kernel header copies, some resulted in new kernel features
being automagically added to 'perf trace' syscall/tracepoint argument
id->string translators.
- Add a file generated during the documentation build to .gitignore.
- Add an option to build without libbfd, as some distros, like Debian
consider its ABI unstable.
- Add support to print a textual representation of IBS raw sample data
in 'perf report'.
- Fix bpf 'perf test' sample mismatch reporting
- Fix passing arguments to stackcollapse report in a 'perf script'
python script.
- Allow build-id with trailing zeros.
- Look for ImageBase in PE file to compute .text offset.
* tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (25 commits)
tools headers UAPI: Update tools's copy of drm.h headers
tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
tools headers UAPI: Sync linux/fs.h with the kernel sources
tools headers UAPI: Sync linux/in.h copy with the kernel sources
perf tools: Add an option to build without libbfd
perf tools: Allow build-id with trailing zeros
perf tools: Fix hybrid config terms list corruption
perf tools: Factor out copy_config_terms() and free_config_terms()
perf tools: Fix perf_event_attr__fprintf() missing/dupl. fields
perf tools: Ignore Documentation dependency file
perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions
tools include UAPI: Update linux/mount.h copy
perf beauty: Cover more flags in the move_mount syscall argument beautifier
tools headers UAPI: Sync linux/prctl.h with the kernel sources
tools include UAPI: Sync sound/asound.h copy with the kernel sources
tools headers UAPI: Sync linux/kvm.h with the kernel sources
tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources
perf report: Add support to print a textual representation of IBS raw sample data
perf report: Add tools/arch/x86/include/asm/amd-ibs.h
perf env: Add perf_env__cpuid, perf_env__{nr_}pmu_mappings
...
Pull compiler attributes updates from Miguel Ojeda:
- Fix __has_attribute(__no_sanitize_coverage__) for GCC 4 (Marco Elver)
- Add Nick as Reviewer for compiler_attributes.h (Nick Desaulniers)
- Move __compiletime_{error|warning} (Nick Desaulniers)
* tag 'compiler-attributes-for-linus-v5.15-rc1-v2' of git://github.com/ojeda/linux:
compiler_attributes.h: move __compiletime_{error|warning}
MAINTAINERS: add Nick as Reviewer for compiler_attributes.h
Compiler Attributes: fix __has_attribute(__no_sanitize_coverage__) for GCC 4
Pull auxdisplay updates from Miguel Ojeda:
"An assortment of improvements for auxdisplay:
- Replace symbolic permissions with octal permissions (Jinchao Wang)
- ks0108: Switch to use module_parport_driver() (Andy Shevchenko)
- charlcd: Drop unneeded initializers and switch to C99 style (Andy
Shevchenko)
- hd44780: Fix oops on module unloading (Lars Poeschel)
- Add I2C gpio expander example (Ralf Schlatterbeck)"
* tag 'auxdisplay-for-linus-v5.15-rc1' of git://github.com/ojeda/linux:
auxdisplay: Replace symbolic permissions with octal permissions
auxdisplay: ks0108: Switch to use module_parport_driver()
auxdisplay: charlcd: Drop unneeded initializers and switch to C99 style
auxdisplay: hd44780: Fix oops on module unloading
auxdisplay: Add I2C gpio expander example
Pull CPU hotplug updates from Thomas Gleixner:
"Updates for the SMP and CPU hotplug:
- Remove DEFINE_SMP_CALL_CACHE_FUNCTION() which is a left over of the
original hotplug code and now causing trouble with the ARM64 cache
topology setup due to the pointless SMP function call.
It's not longer required as the hotplug callbacks are guaranteed to
be invoked on the upcoming CPU.
- Remove the deprecated and now unused CPU hotplug functions
- Rewrite the CPU hotplug API documentation"
* tag 'smp-urgent-2021-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Documentation: core-api/cpuhotplug: Rewrite the API section
cpu/hotplug: Remove deprecated CPU-hotplug functions.
thermal: Replace deprecated CPU-hotplug functions.
drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()
Pull misc driver fix from Greg KH:
"Here is a single patch for 5.15-rc1, for the lkdtm misc driver.
It resolves a build issue that many people were hitting with your
current tree, and Kees and others felt would be good to get merged
before -rc1 comes out, to prevent them from having to constantly hit
it as many development trees restart on -rc1, not older -rc releases.
It has NOT been in linux-next, but has passed 0-day testing and looks
'obviously correct' when reviewing it locally :)"
* tag 'char-misc-5.15-rc1-lkdtm' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
lkdtm: Use init_uts_ns.name instead of macros
Pull IPMI updates from Corey Minyard:
"A couple of very minor fixes for style and rate limiting.
Nothing big, but probably needs to go in"
* tag 'for-linus-5.15-1' of git://github.com/cminyard/linux-ipmi:
char: ipmi: use DEVICE_ATTR helper macro
ipmi: rate limit ipmi smi_event failure message
Pull scheduler fixes from Borislav Petkov:
- Make sure the idle timer expires in hardirq context, on PREEMPT_RT
- Make sure the run-queue balance callback is invoked only on the
outgoing CPU
* tag 'sched_urgent_for_v5.15_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Prevent balance_push() on remote runqueues
sched/idle: Make the idle timer expire in hard interrupt context
Pull locking fixes from Borislav Petkov:
- Fix the futex PI requeue machinery to not return to userspace in
inconsistent state
- Avoid a potential null pointer dereference in the ww_mutex deadlock
check
- Other smaller cleanups and optimizations
* tag 'locking_urgent_for_v5.15_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rtmutex: Fix ww_mutex deadlock check
futex: Remove unused variable 'vpid' in futex_proxy_trylock_atomic()
futex: Avoid redundant task lookup
futex: Clarify comment for requeue_pi_wake_futex()
futex: Prevent inconsistent state and exit race
futex: Return error code instead of assigning it without effect
locking/rwsem: Add missing __init_rwsem() for PREEMPT_RT
Muhammad Falak R Wani
Ravi Bangoria
Linus Torvalds
Nick Desaulniers
Will Deacon