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2020-06-20powerpc/8xx: Provide ptep_get() with 16k pagesChristophe Leroy
READ_ONCE() now enforces atomic read, which leads to: CC mm/gup.o In file included from ./include/linux/kernel.h:11:0, from mm/gup.c:2: In function 'gup_hugepte.constprop', inlined from 'gup_huge_pd.isra.79' at mm/gup.c:2465:8: ./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_222' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE(). _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert' prefix ## suffix(); \ ^ ./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert' compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ ^ ./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type' compiletime_assert_rwonce_type(x); \ ^ mm/gup.c:2428:8: note: in expansion of macro 'READ_ONCE' pte = READ_ONCE(*ptep); ^ In function 'gup_get_pte', inlined from 'gup_pte_range' at mm/gup.c:2228:9, inlined from 'gup_pmd_range' at mm/gup.c:2613:15, inlined from 'gup_pud_range' at mm/gup.c:2641:15, inlined from 'gup_p4d_range' at mm/gup.c:2666:15, inlined from 'gup_pgd_range' at mm/gup.c:2694:15, inlined from 'internal_get_user_pages_fast' at mm/gup.c:2795:3: ./include/linux/compiler.h:392:38: error: call to '__compiletime_assert_219' declared with attribute error: Unsupported access size for {READ,WRITE}_ONCE(). _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:373:4: note: in definition of macro '__compiletime_assert' prefix ## suffix(); \ ^ ./include/linux/compiler.h:392:2: note: in expansion of macro '_compiletime_assert' _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) ^ ./include/linux/compiler.h:405:2: note: in expansion of macro 'compiletime_assert' compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \ ^ ./include/linux/compiler.h:291:2: note: in expansion of macro 'compiletime_assert_rwonce_type' compiletime_assert_rwonce_type(x); \ ^ mm/gup.c:2199:9: note: in expansion of macro 'READ_ONCE' return READ_ONCE(*ptep); ^ make[2]: *** [mm/gup.o] Error 1 Define ptep_get() on 8xx when using 16k pages. Fixes: 9e343b467c70 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Will Deacon <will@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/341688399c1b102756046d19ea6ce39db1ae4742.1592225558.git.christophe.leroy@csgroup.eu
2020-06-19Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "Unfortunately, we still have a number of outstanding issues so there will be more fixes to come, but this lot are a good start. - Fix handling of watchpoints triggered by uaccess routines - Fix initialisation of gigantic pages for CMA buffers - Raise minimum clang version for BTI to avoid miscompilation - Fix data race in SVE vector length configuration code - Ensure address tags are ignored in kern_addr_valid() - Dump register state on fatal BTI exception - kexec_file() cleanup to use struct_size() macro" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: hw_breakpoint: Don't invoke overflow handler on uaccess watchpoints arm64: kexec_file: Use struct_size() in kmalloc() arm64: mm: reserve hugetlb CMA after numa_init arm64: bti: Require clang >= 10.0.1 for in-kernel BTI support arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=n arm64: pgtable: Clear the GP bit for non-executable kernel pages arm64: mm: reset address tag set by kasan sw tagging arm64: traps: Dump registers prior to panic() in bad_mode() arm64/sve: Eliminate data races on sve_default_vl docs/arm64: Fix typo'd #define in sve.rst arm64: remove TEXT_OFFSET randomization
2020-06-19x86/asm/64: Align start of __clear_user() loop to 16-bytesMatt Fleming
x86 CPUs can suffer severe performance drops if a tight loop, such as the ones in __clear_user(), straddles a 16-byte instruction fetch window, or worse, a 64-byte cacheline. This issues was discovered in the SUSE kernel with the following commit, 1153933703d9 ("x86/asm/64: Micro-optimize __clear_user() - Use immediate constants") which increased the code object size from 10 bytes to 15 bytes and caused the 8-byte copy loop in __clear_user() to be split across a 64-byte cacheline. Aligning the start of the loop to 16-bytes makes this fit neatly inside a single instruction fetch window again and restores the performance of __clear_user() which is used heavily when reading from /dev/zero. Here are some numbers from running libmicro's read_z* and pread_z* microbenchmarks which read from /dev/zero: Zen 1 (Naples) libmicro-file 5.7.0-rc6 5.7.0-rc6 5.7.0-rc6 revert-1153933703d9+ align16+ Time mean95-pread_z100k 9.9195 ( 0.00%) 5.9856 ( 39.66%) 5.9938 ( 39.58%) Time mean95-pread_z10k 1.1378 ( 0.00%) 0.7450 ( 34.52%) 0.7467 ( 34.38%) Time mean95-pread_z1k 0.2623 ( 0.00%) 0.2251 ( 14.18%) 0.2252 ( 14.15%) Time mean95-pread_zw100k 9.9974 ( 0.00%) 6.0648 ( 39.34%) 6.0756 ( 39.23%) Time mean95-read_z100k 9.8940 ( 0.00%) 5.9885 ( 39.47%) 5.9994 ( 39.36%) Time mean95-read_z10k 1.1394 ( 0.00%) 0.7483 ( 34.33%) 0.7482 ( 34.33%) Note that this doesn't affect Haswell or Broadwell microarchitectures which seem to avoid the alignment issue by executing the loop straight out of the Loop Stream Detector (verified using perf events). Fixes: 1153933703d9 ("x86/asm/64: Micro-optimize __clear_user() - Use immediate constants") Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: <stable@vger.kernel.org> # v4.19+ Link: https://lkml.kernel.org/r/20200618102002.30034-1-matt@codeblueprint.co.uk
2020-06-19Revert "KVM: VMX: Micro-optimize vmexit time when not exposing PMU"Vitaly Kuznetsov
Guest crashes are observed on a Cascade Lake system when 'perf top' is launched on the host, e.g. BUG: unable to handle kernel paging request at fffffe0000073038 PGD 7ffa7067 P4D 7ffa7067 PUD 7ffa6067 PMD 7ffa5067 PTE ffffffffff120 Oops: 0000 [#1] SMP PTI CPU: 1 PID: 1 Comm: systemd Not tainted 4.18.0+ #380 ... Call Trace: serial8250_console_write+0xfe/0x1f0 call_console_drivers.constprop.0+0x9d/0x120 console_unlock+0x1ea/0x460 Call traces are different but the crash is imminent. The problem was blindly bisected to the commit 041bc42ce2d0 ("KVM: VMX: Micro-optimize vmexit time when not exposing PMU"). It was also confirmed that the issue goes away if PMU is exposed to the guest. With some instrumentation of the guest we can see what is being switched (when we do atomic_switch_perf_msrs()): vmx_vcpu_run: switching 2 msrs vmx_vcpu_run: switching MSR38f guest: 70000000d host: 70000000f vmx_vcpu_run: switching MSR3f1 guest: 0 host: 2 The current guess is that PEBS (MSR_IA32_PEBS_ENABLE, 0x3f1) is to blame. Regardless of whether PMU is exposed to the guest or not, PEBS needs to be disabled upon switch. This reverts commit 041bc42ce2d0efac3b85bbb81dea8c74b81f4ef9. Reported-by: Maxime Coquelin <maxime.coquelin@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20200619094046.654019-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-19x86/platform/intel-mid: convert to use i2c_new_client_device()Wolfram Sang
Move away from the deprecated API and return the shiny new ERRPTR where useful. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-06-18RISC-V: Acquire mmap lock before invoking walk_page_rangeAtish Patra
As per walk_page_range documentation, mmap lock should be acquired by the caller before invoking walk_page_range. mmap_assert_locked gets triggered without that. The details can be found here. http://lists.infradead.org/pipermail/linux-riscv/2020-June/010335.html Fixes: 395a21ff859c(riscv: add ARCH_HAS_SET_DIRECT_MAP support) Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Zong Li <zong.li@sifive.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-18RISC-V: Don't allow write+exec only page mapping request in mmapYash Shah
As per the table 4.4 of version "20190608-Priv-MSU-Ratified" of the RISC-V instruction set manual[0], the PTE permission bit combination of "write+exec only" is reserved for future use. Hence, don't allow such mapping request in mmap call. An issue is been reported by David Abdurachmanov, that while running stress-ng with "sysbadaddr" argument, RCU stalls are observed on RISC-V specific kernel. This issue arises when the stress-sysbadaddr request for pages with "write+exec only" permission bits and then passes the address obtain from this mmap call to various system call. For the riscv kernel, the mmap call should fail for this particular combination of permission bits since it's not valid. [0]: http://dabbelt.com/~palmer/keep/riscv-isa-manual/riscv-privileged-20190608-1.pdf Signed-off-by: Yash Shah <yash.shah@sifive.com> Reported-by: David Abdurachmanov <david.abdurachmanov@gmail.com> [Palmer: Refer to the latest ISA specification at the only link I could find, and update the terminology.] Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-06-18Merge branch 'hch' (maccess patches from Christoph Hellwig)Linus Torvalds
Merge non-faulting memory access cleanups from Christoph Hellwig: "Andrew and I decided to drop the patches implementing your suggested rename of the probe_kernel_* and probe_user_* helpers from -mm as there were way to many conflicts. After -rc1 might be a good time for this as all the conflicts are resolved now" This also adds a type safety checking patch on top of the renaming series to make the subtle behavioral difference between 'get_user()' and 'get_kernel_nofault()' less potentially dangerous and surprising. * emailed patches from Christoph Hellwig <hch@lst.de>: maccess: make get_kernel_nofault() check for minimal type compatibility maccess: rename probe_kernel_address to get_kernel_nofault maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofault maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault
2020-06-18maccess: make get_kernel_nofault() check for minimal type compatibilityLinus Torvalds
Now that we've renamed probe_kernel_address() to get_kernel_nofault() and made it look and behave more in line with get_user(), some of the subtle type behavior differences end up being more obvious and possibly dangerous. When you do get_user(val, user_ptr); the type of the access comes from the "user_ptr" part, and the above basically acts as val = *user_ptr; by design (except, of course, for the fact that the actual dereference is done with a user access). Note how in the above case, the type of the end result comes from the pointer argument, and then the value is cast to the type of 'val' as part of the assignment. So the type of the pointer is ultimately the more important type both for the access itself. But 'get_kernel_nofault()' may now _look_ similar, but it behaves very differently. When you do get_kernel_nofault(val, kernel_ptr); it behaves like val = *(typeof(val) *)kernel_ptr; except, of course, for the fact that the actual dereference is done with exception handling so that a faulting access is suppressed and returned as the error code. But note how different the casting behavior of the two superficially similar accesses are: one does the actual access in the size of the type the pointer points to, while the other does the access in the size of the target, and ignores the pointer type entirely. Actually changing get_kernel_nofault() to act like get_user() is almost certainly the right thing to do eventually, but in the meantime this patch adds logit to at least verify that the pointer type is compatible with the type of the result. In many cases, this involves just casting the pointer to 'void *' to make it obvious that the type of the pointer is not the important part. It's not how 'get_user()' acts, but at least the behavioral difference is now obvious and explicit. Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-18maccess: rename probe_kernel_address to get_kernel_nofaultChristoph Hellwig
Better describe what this helper does, and match the naming of copy_from_kernel_nofault. Also switch the argument order around, so that it acts and looks like get_user(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-18objtool: Fix noinstr vs KCOVPeter Zijlstra
Since many compilers cannot disable KCOV with a function attribute, help it to NOP out any __sanitizer_cov_*() calls injected in noinstr code. This turns: 12: e8 00 00 00 00 callq 17 <lockdep_hardirqs_on+0x17> 13: R_X86_64_PLT32 __sanitizer_cov_trace_pc-0x4 into: 12: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 13: R_X86_64_NONE __sanitizer_cov_trace_pc-0x4 Just like recordmcount does. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dmitry Vyukov <dvyukov@google.com>
2020-06-18arm64: dts: imx8mm-beacon: Fix voltages on LDO1 and LDO2Adam Ford
LDO1 and LDO2 settings are wrong and case the voltage to go above the maximum level of 2.15V permitted by the SoC to 3.0V. This patch is based on work done on the i.MX8M Mini-EVK which utilizes the same fix. Fixes: 593816fa2f35 ("arm64: dts: imx: Add Beacon i.MX8m-Mini development kit") Signed-off-by: Adam Ford <aford173@gmail.com> Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-06-18arm64: hw_breakpoint: Don't invoke overflow handler on uaccess watchpointsWill Deacon
Unprivileged memory accesses generated by the so-called "translated" instructions (e.g. STTR) at EL1 can cause EL0 watchpoints to fire unexpectedly if kernel debugging is enabled. In such cases, the hw_breakpoint logic will invoke the user overflow handler which will typically raise a SIGTRAP back to the current task. This is futile when returning back to the kernel because (a) the signal won't have been delivered and (b) userspace can't handle the thing anyway. Avoid invoking the user overflow handler for watchpoints triggered by kernel uaccess routines, and instead single-step over the faulting instruction as we would if no overflow handler had been installed. (Fixes tag identifies the introduction of unprivileged memory accesses, which exposed this latent bug in the hw_breakpoint code) Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Fixes: 57f4959bad0a ("arm64: kernel: Add support for User Access Override") Reported-by: Luis Machado <luis.machado@linaro.org> Signed-off-by: Will Deacon <will@kernel.org>
2020-06-18arm64: kexec_file: Use struct_size() in kmalloc()Gustavo A. R. Silva
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle and, audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200617213407.GA1385@embeddedor Signed-off-by: Will Deacon <will@kernel.org>
2020-06-18x86/cpu: Use pinning mask for CR4 bits needing to be 0Kees Cook
The X86_CR4_FSGSBASE bit of CR4 should not change after boot[1]. Older kernels should enforce this bit to zero, and newer kernels need to enforce it depending on boot-time configuration (e.g. "nofsgsbase"). To support a pinned bit being either 1 or 0, use an explicit mask in combination with the expected pinned bit values. [1] https://lore.kernel.org/lkml/20200527103147.GI325280@hirez.programming.kicks-ass.net Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/202006082013.71E29A42@keescook
2020-06-18arm64: mm: reserve hugetlb CMA after numa_initBarry Song
hugetlb_cma_reserve() is called at the wrong place. numa_init has not been done yet. so all reserved memory will be located at node0. Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma") Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200617215828.25296-1-song.bao.hua@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
2020-06-18arm64: dts: imx8mn-ddr4-evk: correct ldo1/ldo2 voltage rangeRobin Gong
Correct ldo1 voltage range from wrong high group(3.0V~3.3V) to low group (1.6V~1.9V) because the ldo1 should be 1.8V. Actually, two voltage groups have been supported at bd718x7-regulator driver, hence, just corrrect the voltage range to 1.6V~3.3V. For ldo2@0.8V, correct voltage range too. Otherwise, ldo1 would be kept @3.0V and ldo2@0.9V which violate i.mx8mn datasheet as the below warning log in kernel: [ 0.995524] LDO1: Bringing 1800000uV into 3000000-3000000uV [ 0.999196] LDO2: Bringing 800000uV into 900000-900000uV Fixes: 3e44dd09736d ("arm64: dts: imx8mn-ddr4-evk: Add rohm,bd71847 PMIC support") Cc: stable@vger.kernel.org Signed-off-by: Robin Gong <yibin.gong@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-06-18arm64: dts: imx8mm-evk: correct ldo1/ldo2 voltage rangeRobin Gong
Correct ldo1 voltage range from wrong high group(3.0V~3.3V) to low group (1.6V~1.9V) because the ldo1 should be 1.8V. Actually, two voltage groups have been supported at bd718x7-regulator driver, hence, just corrrect the voltage range to 1.6V~3.3V. For ldo2@0.8V, correct voltage range too. Otherwise, ldo1 would be kept @3.0V and ldo2@0.9V which violate i.mx8mm datasheet as the below warning log in kernel: [ 0.995524] LDO1: Bringing 1800000uV into 3000000-3000000uV [ 0.999196] LDO2: Bringing 800000uV into 900000-900000uV Fixes: 78cc25fa265d ("arm64: dts: imx8mm-evk: Add BD71847 PMIC") Cc: stable@vger.kernel.org Signed-off-by: Robin Gong <yibin.gong@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Reviewed-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-06-17s390: fix syscall_get_error for compat processesDmitry V. Levin
If both the tracer and the tracee are compat processes, and gprs[2] is assigned a value by __poke_user_compat, then the higher 32 bits of gprs[2] are cleared, IS_ERR_VALUE() always returns false, and syscall_get_error() always returns 0. Fix the implementation by sign-extending the value for compat processes the same way as x86 implementation does. The bug was exposed to user space by commit 201766a20e30f ("ptrace: add PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite. This change fixes strace syscall tampering on s390. Link: https://lkml.kernel.org/r/20200602180051.GA2427@altlinux.org Fixes: 753c4dd6a2fa2 ("[S390] ptrace changes") Cc: Elvira Khabirova <lineprinter@altlinux.org> Cc: stable@vger.kernel.org # v2.6.28+ Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-17ARM: dts: NSP: Correct FA2 mailbox nodeMatthew Hagan
The FA2 mailbox is specified at 0x18025000 but should actually be 0x18025c00, length 0x400 according to socregs_nsp.h and board_bu.c. Also the interrupt was off by one and should be GIC SPI 151 instead of 150. Fixes: 17d517172300 ("ARM: dts: NSP: Add mailbox (PDC) to NSP") Signed-off-by: Matthew Hagan <mnhagan88@gmail.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2020-06-17maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofaultChristoph Hellwig
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofaultChristoph Hellwig
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17efi/libstub: arm: Print CPU boot mode and MMU state at bootArd Biesheuvel
On 32-bit ARM, we may boot at HYP mode, or with the MMU and caches off (or both), even though the EFI spec does not actually support this. While booting at HYP mode is something we might tolerate, fiddling with the caches is a more serious issue, as disabling the caches is tricky to do safely from C code, and running without the Dcache makes it impossible to support unaligned memory accesses, which is another explicit requirement imposed by the EFI spec. So take note of the CPU mode and MMU state in the EFI stub diagnostic output so that we can easily diagnose any issues that may arise from this. E.g., EFI stub: Entering in SVC mode with MMU enabled Also, capture the CPSR and SCTLR system register values at EFI stub entry, and after ExitBootServices() returns, and check whether the MMU and Dcache were disabled at any point. If this is the case, a diagnostic message like the following will be emitted: efi: [Firmware Bug]: EFI stub was entered with MMU and Dcache disabled, please fix your firmware! efi: CPSR at EFI stub entry : 0x600001d3 efi: SCTLR at EFI stub entry : 0x00c51838 efi: CPSR after ExitBootServices() : 0x600001d3 efi: SCTLR after ExitBootServices(): 0x00c50838 Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Leif Lindholm <leif@nuviainc.com>
2020-06-17efi/x86: Setup stack correctly for efi_pe_entryArvind Sankar
Commit 17054f492dfd ("efi/x86: Implement mixed mode boot without the handover protocol") introduced a new entry point for the EFI stub to be booted in mixed mode on 32-bit firmware. When entered via efi32_pe_entry, control is first transferred to startup_32 to setup for the switch to long mode, and then the EFI stub proper is entered via efi_pe_entry. efi_pe_entry is an MS ABI function, and the ABI requires 32 bytes of shadow stack space to be allocated by the caller, as well as the stack being aligned to 8 mod 16 on entry. Allocate 40 bytes on the stack before switching to 64-bit mode when calling efi_pe_entry to account for this. For robustness, explicitly align boot_stack_end to 16 bytes. It is currently implicitly aligned since .bss is cacheline-size aligned, head_64.o is the first object file with a .bss section, and the heap and boot sizes are aligned. Fixes: 17054f492dfd ("efi/x86: Implement mixed mode boot without the handover protocol") Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Link: https://lore.kernel.org/r/20200617131957.2507632-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-06-17powerpc/syscalls: Use the number when building SPU syscall tableMichael Ellerman
Currently the macro that inserts entries into the SPU syscall table doesn't actually use the "nr" (syscall number) parameter. This does work, but it relies on the exact right number of syscall entries being emitted in order for the syscal numbers to line up with the array entries. If for example we had two entries with the same syscall number we wouldn't get an error, it would just cause all subsequent syscalls to be off by one in the spu_syscall_table. So instead change the macro to assign to the specific entry of the array, meaning any numbering overlap will be caught by the compiler. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20200616135617.2937252-1-mpe@ellerman.id.au
2020-06-17powerpc/8xx: use pmd_off() to access a PMD entry in pte_update()Mike Rapoport
The pte_update() implementation for PPC_8xx unfolds page table from the PGD level to access a PMD entry. Since 8xx has only 2-level page table this can be simplified with pmd_off() shortcut. Replace explicit unfolding with pmd_off() and drop defines of pgd_index() and pgd_offset() that are no longer needed. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200615092229.23142-1-rppt@kernel.org
2020-06-17arm64: bti: Require clang >= 10.0.1 for in-kernel BTI supportWill Deacon
Unfortunately, most versions of clang that support BTI are capable of miscompiling the kernel when converting a switch statement into a jump table. As an example, attempting to spawn a KVM guest results in a panic: [ 56.253312] Kernel panic - not syncing: bad mode [ 56.253834] CPU: 0 PID: 279 Comm: lkvm Not tainted 5.8.0-rc1 #2 [ 56.254225] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 [ 56.254712] Call trace: [ 56.254952] dump_backtrace+0x0/0x1d4 [ 56.255305] show_stack+0x1c/0x28 [ 56.255647] dump_stack+0xc4/0x128 [ 56.255905] panic+0x16c/0x35c [ 56.256146] bad_el0_sync+0x0/0x58 [ 56.256403] el1_sync_handler+0xb4/0xe0 [ 56.256674] el1_sync+0x7c/0x100 [ 56.256928] kvm_vm_ioctl_check_extension_generic+0x74/0x98 [ 56.257286] __arm64_sys_ioctl+0x94/0xcc [ 56.257569] el0_svc_common+0x9c/0x150 [ 56.257836] do_el0_svc+0x84/0x90 [ 56.258083] el0_sync_handler+0xf8/0x298 [ 56.258361] el0_sync+0x158/0x180 This is because the switch in kvm_vm_ioctl_check_extension_generic() is executed as an indirect branch to tail-call through a jump table: ffff800010032dc8: 3869694c ldrb w12, [x10, x9] ffff800010032dcc: 8b0c096b add x11, x11, x12, lsl #2 ffff800010032dd0: d61f0160 br x11 However, where the target case uses the stack, the landing pad is elided due to the presence of a paciasp instruction: ffff800010032e14: d503233f paciasp ffff800010032e18: a9bf7bfd stp x29, x30, [sp, #-16]! ffff800010032e1c: 910003fd mov x29, sp ffff800010032e20: aa0803e0 mov x0, x8 ffff800010032e24: 940017c0 bl ffff800010038d24 <kvm_vm_ioctl_check_extension> ffff800010032e28: 93407c00 sxtw x0, w0 ffff800010032e2c: a8c17bfd ldp x29, x30, [sp], #16 ffff800010032e30: d50323bf autiasp ffff800010032e34: d65f03c0 ret Unfortunately, this results in a fatal exception because paciasp is compatible only with branch-and-link (call) instructions and not simple indirect branches. A fix is being merged into Clang 10.0.1 so that a 'bti j' instruction is emitted as an explicit landing pad in this situation. Make in-kernel BTI depend on that compiler version when building with clang. Cc: Tom Stellard <tstellar@redhat.com> Cc: Daniel Kiss <daniel.kiss@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20200615105524.GA2694@willie-the-truck Link: https://lore.kernel.org/r/20200616183630.2445-1-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-06-17x86/resctrl: Fix a NULL vs IS_ERR() static checker warning in rdt_cdp_peer_get()Dan Carpenter
The callers don't expect *d_cdp to be set to an error pointer, they only check for NULL. This leads to a static checker warning: arch/x86/kernel/cpu/resctrl/rdtgroup.c:2648 __init_one_rdt_domain() warn: 'd_cdp' could be an error pointer This would not trigger a bug in this specific case because __init_one_rdt_domain() calls it with a valid domain that would not have a negative id and thus not trigger the return of the ERR_PTR(). If this was a negative domain id then the call to rdt_find_domain() in domain_add_cpu() would have returned the ERR_PTR() much earlier and the creation of the domain with an invalid id would have been prevented. Even though a bug is not triggered currently the right and safe thing to do is to set the pointer to NULL because that is what can be checked for when the caller is handling the CDP and non-CDP cases. Fixes: 52eb74339a62 ("x86/resctrl: Fix rdt_find_domain() return value and checks") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Acked-by: Fenghua Yu <fenghua.yu@intel.com> Link: https://lkml.kernel.org/r/20200602193611.GA190851@mwanda
2020-06-17kconfig: unify cc-option and as-optionMasahiro Yamada
cc-option and as-option are almost the same; both pass the flag to $(CC). The main difference is the cc-option stops before the assemble stage (-S option) whereas as-option stops after (-c option). I chose -S because it is slightly faster, but $(cc-option,-gz=zlib) returns a wrong result (https://lkml.org/lkml/2020/6/9/1529). It has been fixed by commit 7b16994437c7 ("Makefile: Improve compressed debug info support detection"), but the assembler should always be invoked for more reliable compiler option tests. However, you cannot simply replace -S with -c because the following code in lib/Kconfig.debug would break: depends on $(cc-option,-gsplit-dwarf) The combination of -c and -gsplit-dwarf does not accept /dev/null as output. $ cat /dev/null | gcc -gsplit-dwarf -S -x c - -o /dev/null $ echo $? 0 $ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o /dev/null objcopy: Warning: '/dev/null' is not an ordinary file $ echo $? 1 $ cat /dev/null | gcc -gsplit-dwarf -c -x c - -o tmp.o $ echo $? 0 There is another flag that creates an separate file based on the object file path: $ cat /dev/null | gcc -ftest-coverage -c -x c - -o /dev/null <stdin>:1: error: cannot open /dev/null.gcno So, we cannot use /dev/null to sink the output. Align the cc-option implementation with scripts/Kbuild.include. With -c option used in cc-option, as-option is unneeded. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Will Deacon <will@kernel.org>
2020-06-16kretprobe: Prevent triggering kretprobe from within kprobe_flush_taskJiri Olsa
Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave. My test was also able to trigger lockdep output: ============================================ WARNING: possible recursive locking detected 5.6.0-rc6+ #6 Not tainted -------------------------------------------- sched-messaging/2767 is trying to acquire lock: ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0 but task is already holding lock: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(kretprobe_table_locks[i].lock)); lock(&(kretprobe_table_locks[i].lock)); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by sched-messaging/2767: #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 stack backtrace: CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6 Call Trace: dump_stack+0x96/0xe0 __lock_acquire.cold.57+0x173/0x2b7 ? native_queued_spin_lock_slowpath+0x42b/0x9e0 ? lockdep_hardirqs_on+0x590/0x590 ? __lock_acquire+0xf63/0x4030 lock_acquire+0x15a/0x3d0 ? kretprobe_hash_lock+0x52/0xa0 _raw_spin_lock_irqsave+0x36/0x70 ? kretprobe_hash_lock+0x52/0xa0 kretprobe_hash_lock+0x52/0xa0 trampoline_handler+0xf8/0x940 ? kprobe_fault_handler+0x380/0x380 ? find_held_lock+0x3a/0x1c0 kretprobe_trampoline+0x25/0x50 ? lock_acquired+0x392/0xbc0 ? _raw_spin_lock_irqsave+0x50/0x70 ? __get_valid_kprobe+0x1f0/0x1f0 ? _raw_spin_unlock_irqrestore+0x3b/0x40 ? finish_task_switch+0x4b9/0x6d0 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 The code within the kretprobe handler checks for probe reentrancy, so we won't trigger any _raw_spin_lock_irqsave probe in there. The problem is in outside kprobe_flush_task, where we call: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave where _raw_spin_lock_irqsave triggers the kretprobe and installs kretprobe_trampoline handler on _raw_spin_lock_irqsave return. The kretprobe_trampoline handler is then executed with already locked kretprobe_table_locks, and first thing it does is to lock kretprobe_table_locks ;-) the whole lockup path like: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed ---> kretprobe_table_locks locked kretprobe_trampoline trampoline_handler kretprobe_hash_lock(current, &head, &flags); <--- deadlock Adding kprobe_busy_begin/end helpers that mark code with fake probe installed to prevent triggering of another kprobe within this code. Using these helpers in kprobe_flush_task, so the probe recursion protection check is hit and the probe is never set to prevent above lockup. Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2 Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking") Cc: Ingo Molnar <mingo@kernel.org> Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-06-16Merge tag 'flex-array-conversions-5.8-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux Pull flexible-array member conversions from Gustavo A. R. Silva: "Replace zero-length arrays with flexible-array members. Notice that all of these patches have been baking in linux-next for two development cycles now. There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. C99 introduced “flexible array members”, which lacks a numeric size for the array declaration entirely: struct something { size_t count; struct foo items[]; }; This is the way the kernel expects dynamically sized trailing elements to be declared. It allows the compiler to generate errors when the flexible array does not occur last in the structure, which helps to prevent some kind of undefined behavior[3] bugs from being inadvertently introduced to the codebase. It also allows the compiler to correctly analyze array sizes (via sizeof(), CONFIG_FORTIFY_SOURCE, and CONFIG_UBSAN_BOUNDS). For instance, there is no mechanism that warns us that the following application of the sizeof() operator to a zero-length array always results in zero: struct something { size_t count; struct foo items[0]; }; struct something *instance; instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL); instance->count = count; size = sizeof(instance->items) * instance->count; memcpy(instance->items, source, size); At the last line of code above, size turns out to be zero, when one might have thought it represents the total size in bytes of the dynamic memory recently allocated for the trailing array items. Here are a couple examples of this issue[4][5]. Instead, flexible array members have incomplete type, and so the sizeof() operator may not be applied[6], so any misuse of such operators will be immediately noticed at build time. The cleanest and least error-prone way to implement this is through the use of a flexible array member: struct something { size_t count; struct foo items[]; }; struct something *instance; instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL); instance->count = count; size = sizeof(instance->items[0]) * instance->count; memcpy(instance->items, source, size); instead" [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") [4] commit f2cd32a443da ("rndis_wlan: Remove logically dead code") [5] commit ab91c2a89f86 ("tpm: eventlog: Replace zero-length array with flexible-array member") [6] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html * tag 'flex-array-conversions-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (41 commits) w1: Replace zero-length array with flexible-array tracing/probe: Replace zero-length array with flexible-array soc: ti: Replace zero-length array with flexible-array tifm: Replace zero-length array with flexible-array dmaengine: tegra-apb: Replace zero-length array with flexible-array stm class: Replace zero-length array with flexible-array Squashfs: Replace zero-length array with flexible-array ASoC: SOF: Replace zero-length array with flexible-array ima: Replace zero-length array with flexible-array sctp: Replace zero-length array with flexible-array phy: samsung: Replace zero-length array with flexible-array RxRPC: Replace zero-length array with flexible-array rapidio: Replace zero-length array with flexible-array media: pwc: Replace zero-length array with flexible-array firmware: pcdp: Replace zero-length array with flexible-array oprofile: Replace zero-length array with flexible-array block: Replace zero-length array with flexible-array tools/testing/nvdimm: Replace zero-length array with flexible-array libata: Replace zero-length array with flexible-array kprobes: Replace zero-length array with flexible-array ...
2020-06-16x86/purgatory: Add -fno-stack-protectorArvind Sankar
The purgatory Makefile removes -fstack-protector options if they were configured in, but does not currently add -fno-stack-protector. If gcc was configured with the --enable-default-ssp configure option, this results in the stack protector still being enabled for the purgatory (absent distro-specific specs files that might disable it again for freestanding compilations), if the main kernel is being compiled with stack protection enabled (if it's disabled for the main kernel, the top-level Makefile will add -fno-stack-protector). This will break the build since commit e4160b2e4b02 ("x86/purgatory: Fail the build if purgatory.ro has missing symbols") and prior to that would have caused runtime failure when trying to use kexec. Explicitly add -fno-stack-protector to avoid this, as done in other Makefiles that need to disable the stack protector. Reported-by: Gabriel C <nix.or.die@googlemail.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-16arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=nWill Deacon
When I squashed the 'allnoconfig' compiler warning about the set_sve_default_vl() function being defined but not used in commit 1e570f512cbd ("arm64/sve: Eliminate data races on sve_default_vl"), I accidentally broke the build for configs where ARM64_SVE is enabled, but SYSCTL is not. Fix this by only compiling the SVE sysctl support if both CONFIG_SVE=y and CONFIG_SYSCTL=y. Cc: Dave Martin <Dave.Martin@arm.com> Reported-by: Qian Cai <cai@lca.pw> Link: https://lore.kernel.org/r/20200616131808.GA1040@lca.pw Signed-off-by: Will Deacon <will@kernel.org>
2020-06-16Merge branch 'omap-for-v5.8/fixes-rc1' into fixesTony Lindgren
2020-06-16Merge tag 'v5.8-rc1' into fixesTony Lindgren
Linux 5.8-rc1
2020-06-16arm64: pgtable: Clear the GP bit for non-executable kernel pagesWill Deacon
Commit cca98e9f8b5e ("mm: enforce that vmap can't map pages executable") introduced 'pgprot_nx(prot)' for arm64 but collided silently with the BTI support during the merge window, which endeavours to clear the GP bit for non-executable kernel mappings in set_memory_nx(). For consistency between the two APIs, clear the GP bit in pgprot_nx(). Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200615154642.3579-1-will@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-06-16ARM: dts: am5729: beaglebone-ai: fix rgmii phy-modeDrew Fustini
Since commit cd28d1d6e52e ("net: phy: at803x: Disable phy delay for RGMII mode") the networking is broken on the BeagleBone AI which has the AR8035 PHY for Gigabit Ethernet [0]. The fix is to switch from phy-mode = "rgmii" to phy-mode = "rgmii-rxid". Note: Grygorii made a similar DT fix for other AM57xx boards with a different phy in commit 820f8a870f65 ("ARM: dts: am57xx: fix networking on boards with ksz9031 phy"). [0] https://git.io/Jf7PX Fixes: 520557d4854b ("ARM: dts: am5729: beaglebone-ai: adding device tree") Cc: Vinod Koul <vkoul@kernel.org> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Robert Nelson <robertcnelson@gmail.com> Signed-off-by: Drew Fustini <drew@beagleboard.org> Signed-off-by: Tony Lindgren <tony@atomide.com>
2020-06-16ARM: dts: Fix omap4 system timer source clocksTony Lindgren
I accidentally flipped the system timer to use system clock instead of the 32k source clock. Fixes: 14b1925a7219 ("ARM: dts: Configure system timers for omap4") Signed-off-by: Tony Lindgren <tony@atomide.com>
2020-06-16ARM: dts: Fix duovero smsc interrupt for suspendTony Lindgren
While testing the recent suspend and resume regressions I noticed that duovero can still end up losing edge gpio interrupts on runtime suspend. This causes NFSroot easily stopping working after resume on duovero. Let's fix the issue by using gpio level interrupts for smsc as then the gpio interrupt state is seen by the gpio controller on resume. Fixes: 731b409878a3 ("ARM: dts: Configure duovero for to allow core retention during idle") Signed-off-by: Tony Lindgren <tony@atomide.com>
2020-06-16ARM: dts: am335x-pocketbeagle: Fix mmc0 Write ProtectDrew Fustini
AM3358 pin mcasp0_aclkr (ZCZ ball B13) [0] is routed to P1.31 header [1] Mode 4 of this pin is mmc0_sdwp (SD Write Protect). A signal connected to P1.31 may accidentally trigger mmc0 write protection. To avoid this situation, do not put mcasp0_aclkr in mode 4 (mmc0_sdwp) by default. [0] http://www.ti.com/lit/ds/symlink/am3358.pdf [1] https://github.com/beagleboard/pocketbeagle/wiki/System-Reference-Manual#531_Expansion_Headers Fixes: 047905376a16 (ARM: dts: Add am335x-pocketbeagle) Signed-off-by: Robert Nelson <robertcnelson@gmail.com> Signed-off-by: Drew Fustini <drew@beagleboard.org> Signed-off-by: Tony Lindgren <tony@atomide.com>
2020-06-16s390/numa: let NODES_SHIFT depend on NEED_MULTIPLE_NODESHeiko Carstens
Qian Cai reported: """ When NUMA=n and nr_node_ids=2, in apply_wqattrs_prepare(), it has, for_each_node(node) { if (wq_calc_node_cpumask(... where it will trigger a booting warning, WARNING: workqueue cpumask: online intersect > possible intersect because it found 2 nodes and wq_numa_possible_cpumask[1] is an empty cpumask. """ Let NODES_SHIFT depend on NEED_MULTIPLE_NODES like it is done on other architectures in order to fix this. Fixes: 701dc81e7412 ("s390/mm: remove fake numa support") Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/vdso: fix vDSO clock_getres()Vincenzo Frascino
clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the s390 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Link: https://lkml.kernel.org/r/20200324121027.21665-1-vincenzo.frascino@arm.com Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [heiko.carstens@de.ibm.com: use llgf for proper zero extension] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/vdso: Use $(LD) instead of $(CC) to link vDSONathan Chancellor
Currently, the VDSO is being linked through $(CC). This does not match how the rest of the kernel links objects, which is through the $(LD) variable. When clang is built in a default configuration, it first attempts to use the target triple's default linker, which is just ld. However, the user can override this through the CLANG_DEFAULT_LINKER cmake define so that clang uses another linker by default, such as LLVM's own linker, ld.lld. This can be useful to get more optimized links across various different projects. However, this is problematic for the s390 vDSO because ld.lld does not have any s390 emulatiom support: https://github.com/llvm/llvm-project/blob/llvmorg-10.0.1-rc1/lld/ELF/Driver.cpp#L132-L150 Thus, if a user is using a toolchain with ld.lld as the default, they will see an error, even if they have specified ld.bfd through the LD make variable: $ make -j"$(nproc)" -s ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- LLVM=1 \ LD=s390x-linux-gnu-ld \ defconfig arch/s390/kernel/vdso64/ ld.lld: error: unknown emulation: elf64_s390 clang-11: error: linker command failed with exit code 1 (use -v to see invocation) Normally, '-fuse-ld=bfd' could be used to get around this; however, this can be fragile, depending on paths and variable naming. The cleaner solution for the kernel is to take advantage of the fact that $(LD) can be invoked directly, which bypasses the heuristics of $(CC) and respects the user's choice. Similar changes have been done for ARM, ARM64, and MIPS. Link: https://lkml.kernel.org/r/20200602192523.32758-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/1041 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> [heiko.carstens@de.ibm.com: add --build-id flag] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/protvirt: use scnprintf() instead of snprintf()Chen Zhou
snprintf() returns the number of bytes that would be written, which may be greater than the the actual length to be written. uv_query_facilities() should return the number of bytes printed into the buffer. This is the return value of scnprintf(). The other functions are the same. Link: https://lkml.kernel.org/r/20200509085608.41061-4-chenzhou10@huawei.com Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390: use scnprintf() in sys_##_prefix##_##_name##_showChen Zhou
snprintf() returns the number of bytes that would be written, which may be greater than the the actual length to be written. show() methods should return the number of bytes printed into the buffer. This is the return value of scnprintf(). Link: https://lkml.kernel.org/r/20200509085608.41061-3-chenzhou10@huawei.com Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/crypto: use scnprintf() instead of snprintf()Chen Zhou
snprintf() returns the number of bytes that would be written, which may be greater than the the actual length to be written. show() methods should return the number of bytes printed into the buffer. This is the return value of scnprintf(). Link: https://lkml.kernel.org/r/20200509085608.41061-2-chenzhou10@huawei.com Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/ptrace: fix setting syscall numberSven Schnelle
When strace wants to update the syscall number, it sets GPR2 to the desired number and updates the GPR via PTRACE_SETREGSET. It doesn't update regs->int_code which would cause the old syscall executed on syscall restart. As we cannot change the ptrace ABI and don't have a field for the interruption code, check whether the tracee is in a syscall and the last instruction was svc. In that case assume that the tracer wants to update the syscall number and copy the GPR2 value to regs->int_code. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/ptrace: pass invalid syscall numbers to tracingSven Schnelle
tracing expects to see invalid syscalls, so pass it through. The syscall path in entry.S checks the syscall number before looking up the handler, so it is still safe. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/ptrace: return -ENOSYS when invalid syscall is suppliedSven Schnelle
The current code returns the syscall number which an invalid syscall number is supplied and tracing is enabled. This makes the strace testsuite fail. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16s390/seccomp: pass syscall arguments via seccomp_dataSven Schnelle
Use __secure_computing() and pass the register data via seccomp_data so secure computing doesn't have to fetch it again. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>