Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler
KVM guests have certain restrictions and performance quirks when using doorbells. This patch moves the EPAPR KVM guest test so it can be shared with PSERIES, and uses that in doorbell setup code to apply the KVM guest quirks and improves IPI performance for two cases: - PowerVM guests may now use doorbells even if they are secure. - KVM guests no longer use doorbells if XIVE is available. There is a valid complaint that "KVM guest" is not a very reasonable thing to test for, it's preferable for the hypervisor to advertise particular behaviours to the guest so they could change if the hypervisor implementation or configuration changes. However in this case we were already assuming a KVM guest worst case, so this patch is about containing those quirks. If KVM later advertises fast doorbells, we should test for that and override the quirks. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com
The only thing in this file is eeh_dev_init() which is allocates and initialises an eeh_dev based on a pci_dn. This is only ever called from pci_dn.c so move it into there and remove the file. Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200725081231.39076-2-oohall@gmail.com
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
syzkaller is picking up a bunch of crashes that look like this:
Unrecoverable exception 380 at c00000000037ed60 (msr=8000000000001031)
Oops: Unrecoverable exception, sig: 6 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 0 PID: 874 Comm: syz-executor.0 Not tainted 5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e #0
NIP: c00000000037ed60 LR: c00000000004bac8 CTR: c000000000030990
REGS: c0000000555a7230 TRAP: 0380 Not tainted (5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e)
MSR: 8000000000001031 <SF,ME,IR,DR,LE> CR: 48222882 XER: 20000000
CFAR: c00000000004bac4 IRQMASK: 0
GPR00: c00000000004bb68 c0000000555a74c0 c0000000024b3500 0000000000000005
GPR04: 0000000000000000 0000000000000000 c00000000004bb88 c008000000910000
GPR08: 00000000000b0000 c00000000004bac8 0000000000016000 c000000002503500
GPR12: c000000000030990 c000000003190000 00000000106a5898 00000000106a0000
GPR16: 00000000106a5890 c000000007a92000 c000000008180e00 c000000007a8f700
GPR20: c000000007a904b0 0000000010110000 c00000000259d318 5deadbeef0000100
GPR24: 5deadbeef0000122 c000000078422700 c000000009ee88b8 c000000078422778
GPR28: 0000000000000001 800000000280b033 0000000000000000 c0000000555a75a0
NIP [c00000000037ed60] __sanitizer_cov_trace_pc+0x40/0x50
LR [c00000000004bac8] interrupt_exit_kernel_prepare+0x118/0x310
Call Trace:
[c0000000555a74c0] [c00000000004bb68] interrupt_exit_kernel_prepare+0x1b8/0x310 (unreliable)
[c0000000555a7530] [c00000000000f9a8] interrupt_return+0x118/0x1c0
--- interrupt: 900 at __sanitizer_cov_trace_pc+0x0/0x50
...<random previous call chain>...
This is caused by __sanitizer_cov_trace_pc() causing an SLB fault
after MSR[RI] has been cleared by __hard_EE_RI_disable(), which we
can not recover from.
Do not instrument the new syscall/interrupt entry/exit code with KCOV,
GCOV or UBSAN.
Reported-by: syzbot-ppc64 <ozlabsyz@au1.ibm.com>
Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There are numerous references to 32bit functions in generic and 64bit code so ifdef them out. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e5619617020ef3a1f54f0c076e7d74cb9ec9f3bf.1584699455.git.msuchanek@suse.de
In order to allow splitting of ptrace depending on the different CONFIG_ options, create a subdirectory dedicated to ptrace and move ptrace.c and ptrace32.c into it. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9ebcbe37834e9d447dd97f4381084795a673260c.1582848567.git.christophe.leroy@c-s.fr
System call entry and particularly exit code is beyond the limit of what is reasonable to implement in asm. This conversion moves all conditional branches out of the asm code, except for the case that all GPRs should be restored at exit. Null syscall test is about 5% faster after this patch, because the exit work is handled under local_irq_disable, and the hard mask and pending interrupt replay is handled after that, which avoids games with MSR. mpe: Includes subsequent fixes from Nick: This fixes 4 issues caught by TM selftests. First was a tm-syscall bug that hit due to tabort_syscall being called after interrupts were reconciled (in a subsequent patch), which led to interrupts being enabled before tabort_syscall was called. Rather than going through an un-reconciling interrupts for the return, I just go back to putting the test early in asm, the C-ification of that wasn't a big win anyway. Second is the syscall return _TIF_USER_WORK_MASK check would go into an infinite loop if _TIF_RESTORE_TM became set. The asm code uses _TIF_USER_WORK_MASK to brach to slowpath which includes restore_tm_state. Third is system call return was not calling restore_tm_state, I missed this completely (alhtough it's in the return from interrupt C conversion because when the asm syscall code encountered problems it would branch to the interrupt return code. Fourth is MSR_VEC missing from restore_math, which was caught by tm-unavailable selftest taking an unexpected facility unavailable interrupt when testing VSX unavailble exception with MSR.FP=1 MSR.VEC=1. Fourth case also has a fixup in a subsequent patch. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200225173541.1549955-26-npiggin@gmail.com
This implements the tricky tracing and soft irq handling bits in C, leaving the low level bit to asm. A functional difference is that this redirects the interrupt exit to a return stub to execute blr, rather than the lr address itself. This is probably barely measurable on real hardware, but it keeps the link stack balanced. Tested with QEMU. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Move power4_fixup_nap back into exceptions-64s.S] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190711022404.18132-1-npiggin@gmail.com
LLVM revision r374662 gives LLVM the ability to convert certain loops
into a reference to bcmp as an optimization; this breaks
prom_init_check.sh:
CALL arch/powerpc/kernel/prom_init_check.sh
Error: External symbol 'bcmp' referenced from prom_init.c
make[2]: *** [arch/powerpc/kernel/Makefile:196: prom_init_check] Error 1
bcmp is defined in lib/string.c as a wrapper for memcmp so this could
be added to the whitelist. However, commit
450e7dd4001f ("powerpc/prom_init: don't use string functions from
lib/") copied memcmp as prom_memcmp to avoid KASAN instrumentation so
having bcmp be resolved to regular memcmp would break that assumption.
Furthermore, because the compiler is the one that inserted bcmp, we
cannot provide something like prom_bcmp.
To prevent LLVM from being clever with optimizations like this, use
-ffreestanding to tell LLVM we are not hosted so it is not free to
make transformations like this.
Reviewed-by: Nick Desaulneris <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-4-natechancellor@gmail.com