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2018-08-07MIPS: Always specify -EB or -EL when using clangPaul Burton
When building using clang, always specify -EB or -EL in order to ensure we target the desired endianness. Since clang cross compiles using a single compiler build with multiple targets, our -dumpmachine tests which don't specify clang's --target argument check output based upon the build machine rather than the machine our build will target. This means our detection of whether to specify -EB fails miserably & we never do. Providing the endianness flag unconditionally for clang resolves this issue & simplifies the clang path somewhat. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-07x86/mm/pti: Clone kernel-image on PTE level for 32 bitJoerg Roedel
On 32 bit the kernel sections are not huge-page aligned. When we clone them on PMD-level we unevitably map some areas that are normal kernel memory and may contain secrets to user-space. To prevent that we need to clone the kernel-image on PTE-level for 32 bit. Also make the page-table cloning code more general so that it can handle PMD and PTE level cloning. This can be generalized further in the future to also handle clones on the P4D-level. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1533637471-30953-4-git-send-email-joro@8bytes.org
2018-08-07x86/mm/pti: Don't clear permissions in pti_clone_pmd()Joerg Roedel
The function sets the global-bit on cloned PMD entries, which only makes sense when the permissions are identical between the user and the kernel page-table. Further, only write-permissions are cleared for entry-text and kernel-text sections, which are not writeable at the end of the boot process. The reason why this RW clearing exists is that in the early PTI implementations the cloned kernel areas were set up during early boot before the kernel text is set to read only and not touched afterwards. This is not longer true. The cloned areas are still set up early to get the entry code working for interrupts and other things, but after the kernel text has been set RO the clone is repeated which copies the RO PMD/PTEs over to the user visible clone. That means the initial clearing of the writable bit can be avoided. [ tglx: Amended changelog ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Dave Hansen <dave.hansen@intel.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1533637471-30953-3-git-send-email-joro@8bytes.org
2018-08-07x86/paravirt: Fix spectre-v2 mitigations for paravirt guestsPeter Zijlstra
Nadav reported that on guests we're failing to rewrite the indirect calls to CALLEE_SAVE paravirt functions. In particular the pv_queued_spin_unlock() call is left unpatched and that is all over the place. This obviously wrecks Spectre-v2 mitigation (for paravirt guests) which relies on not actually having indirect calls around. The reason is an incorrect clobber test in paravirt_patch_call(); this function rewrites an indirect call with a direct call to the _SAME_ function, there is no possible way the clobbers can be different because of this. Therefore remove this clobber check. Also put WARNs on the other patch failure case (not enough room for the instruction) which I've not seen trigger in my (limited) testing. Three live kernel image disassemblies for lock_sock_nested (as a small function that illustrates the problem nicely). PRE is the current situation for guests, POST is with this patch applied and NATIVE is with or without the patch for !guests. PRE: (gdb) disassemble lock_sock_nested Dump of assembler code for function lock_sock_nested: 0xffffffff817be970 <+0>: push %rbp 0xffffffff817be971 <+1>: mov %rdi,%rbp 0xffffffff817be974 <+4>: push %rbx 0xffffffff817be975 <+5>: lea 0x88(%rbp),%rbx 0xffffffff817be97c <+12>: callq 0xffffffff819f7160 <_cond_resched> 0xffffffff817be981 <+17>: mov %rbx,%rdi 0xffffffff817be984 <+20>: callq 0xffffffff819fbb00 <_raw_spin_lock_bh> 0xffffffff817be989 <+25>: mov 0x8c(%rbp),%eax 0xffffffff817be98f <+31>: test %eax,%eax 0xffffffff817be991 <+33>: jne 0xffffffff817be9ba <lock_sock_nested+74> 0xffffffff817be993 <+35>: movl $0x1,0x8c(%rbp) 0xffffffff817be99d <+45>: mov %rbx,%rdi 0xffffffff817be9a0 <+48>: callq *0xffffffff822299e8 0xffffffff817be9a7 <+55>: pop %rbx 0xffffffff817be9a8 <+56>: pop %rbp 0xffffffff817be9a9 <+57>: mov $0x200,%esi 0xffffffff817be9ae <+62>: mov $0xffffffff817be993,%rdi 0xffffffff817be9b5 <+69>: jmpq 0xffffffff81063ae0 <__local_bh_enable_ip> 0xffffffff817be9ba <+74>: mov %rbp,%rdi 0xffffffff817be9bd <+77>: callq 0xffffffff817be8c0 <__lock_sock> 0xffffffff817be9c2 <+82>: jmp 0xffffffff817be993 <lock_sock_nested+35> End of assembler dump. POST: (gdb) disassemble lock_sock_nested Dump of assembler code for function lock_sock_nested: 0xffffffff817be970 <+0>: push %rbp 0xffffffff817be971 <+1>: mov %rdi,%rbp 0xffffffff817be974 <+4>: push %rbx 0xffffffff817be975 <+5>: lea 0x88(%rbp),%rbx 0xffffffff817be97c <+12>: callq 0xffffffff819f7160 <_cond_resched> 0xffffffff817be981 <+17>: mov %rbx,%rdi 0xffffffff817be984 <+20>: callq 0xffffffff819fbb00 <_raw_spin_lock_bh> 0xffffffff817be989 <+25>: mov 0x8c(%rbp),%eax 0xffffffff817be98f <+31>: test %eax,%eax 0xffffffff817be991 <+33>: jne 0xffffffff817be9ba <lock_sock_nested+74> 0xffffffff817be993 <+35>: movl $0x1,0x8c(%rbp) 0xffffffff817be99d <+45>: mov %rbx,%rdi 0xffffffff817be9a0 <+48>: callq 0xffffffff810a0c20 <__raw_callee_save___pv_queued_spin_unlock> 0xffffffff817be9a5 <+53>: xchg %ax,%ax 0xffffffff817be9a7 <+55>: pop %rbx 0xffffffff817be9a8 <+56>: pop %rbp 0xffffffff817be9a9 <+57>: mov $0x200,%esi 0xffffffff817be9ae <+62>: mov $0xffffffff817be993,%rdi 0xffffffff817be9b5 <+69>: jmpq 0xffffffff81063aa0 <__local_bh_enable_ip> 0xffffffff817be9ba <+74>: mov %rbp,%rdi 0xffffffff817be9bd <+77>: callq 0xffffffff817be8c0 <__lock_sock> 0xffffffff817be9c2 <+82>: jmp 0xffffffff817be993 <lock_sock_nested+35> End of assembler dump. NATIVE: (gdb) disassemble lock_sock_nested Dump of assembler code for function lock_sock_nested: 0xffffffff817be970 <+0>: push %rbp 0xffffffff817be971 <+1>: mov %rdi,%rbp 0xffffffff817be974 <+4>: push %rbx 0xffffffff817be975 <+5>: lea 0x88(%rbp),%rbx 0xffffffff817be97c <+12>: callq 0xffffffff819f7160 <_cond_resched> 0xffffffff817be981 <+17>: mov %rbx,%rdi 0xffffffff817be984 <+20>: callq 0xffffffff819fbb00 <_raw_spin_lock_bh> 0xffffffff817be989 <+25>: mov 0x8c(%rbp),%eax 0xffffffff817be98f <+31>: test %eax,%eax 0xffffffff817be991 <+33>: jne 0xffffffff817be9ba <lock_sock_nested+74> 0xffffffff817be993 <+35>: movl $0x1,0x8c(%rbp) 0xffffffff817be99d <+45>: mov %rbx,%rdi 0xffffffff817be9a0 <+48>: movb $0x0,(%rdi) 0xffffffff817be9a3 <+51>: nopl 0x0(%rax) 0xffffffff817be9a7 <+55>: pop %rbx 0xffffffff817be9a8 <+56>: pop %rbp 0xffffffff817be9a9 <+57>: mov $0x200,%esi 0xffffffff817be9ae <+62>: mov $0xffffffff817be993,%rdi 0xffffffff817be9b5 <+69>: jmpq 0xffffffff81063ae0 <__local_bh_enable_ip> 0xffffffff817be9ba <+74>: mov %rbp,%rdi 0xffffffff817be9bd <+77>: callq 0xffffffff817be8c0 <__lock_sock> 0xffffffff817be9c2 <+82>: jmp 0xffffffff817be993 <lock_sock_nested+35> End of assembler dump. Fixes: 63f70270ccd9 ("[PATCH] i386: PARAVIRT: add common patching machinery") Fixes: 3010a0663fd9 ("x86/paravirt, objtool: Annotate indirect calls") Reported-by: Nadav Amit <namit@vmware.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: stable@vger.kernel.org
2018-08-07MIPS: Use dins to simplify __write_64bit_c0_split()Paul Burton
The code in __write_64bit_c0_split() is used by MIPS32 kernels running on MIPS64 CPUs to write a 64-bit value to a 64-bit coprocessor 0 register using a single 64-bit dmtc0 instruction. It does this by combining the 2x 32-bit registers used to hold the 64-bit value into a single register, which in the existing code involves three steps: 1) Zero extend register A which holds bits 31:0 of our data, since it may have previously held a sign-extended value. 2) Shift register B which holds bits 63:32 of our data in bits 31:0 left by 32 bits, such that the bits forming our data are in the position they'll be in the final 64-bit value & bits 31:0 of the register are zero. 3) Or the two registers together to form the 64-bit value in one 64-bit register. From MIPS r2 onwards we have a dins instruction which can effectively perform all 3 of those steps using a single instruction. Add a path for MIPS r2 & beyond which uses dins to take bits 31:0 from register B & insert them into bits 63:32 of register A, giving us our full 64-bit value in register A with one instruction. Since we know that MIPS r2 & above support the sel field for the dmtc0 instruction, we don't bother special casing sel==0. Omiting the sel field would assemble to exactly the same instruction as when we explicitly specify that it equals zero. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-07MIPS: Use read-write output operand in __write_64bit_c0_split()Paul Burton
Commit c22c80431055 ("MIPS: Fix input modify in __write_64bit_c0_split()") modified __write_64bit_c0_split() constraints such that we have both an input & an output which we hope to assign to the same registers, and modify the output rather than incorrectly clobbering an input. The way in which we use both an output & an input parameter with the input constrained to share the output registers is a little convoluted & also problematic for clang, which complains if the input & output values have different widths. For example: In file included from kernel/fork.c:98: ./arch/mips/include/asm/mmu_context.h:149:19: error: unsupported inline asm: input with type 'unsigned long' matching output with type 'unsigned long long' write_c0_entryhi(cpu_asid(cpu, next)); ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~ ./arch/mips/include/asm/mmu_context.h:93:2: note: expanded from macro 'cpu_asid' (cpu_context((cpu), (mm)) & cpu_asid_mask(&cpu_data[cpu])) ^ ./arch/mips/include/asm/mipsregs.h:1617:65: note: expanded from macro 'write_c0_entryhi' #define write_c0_entryhi(val) __write_ulong_c0_register($10, 0, val) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ ./arch/mips/include/asm/mipsregs.h:1430:39: note: expanded from macro '__write_ulong_c0_register' __write_64bit_c0_register(reg, sel, val); \ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~ ./arch/mips/include/asm/mipsregs.h:1400:41: note: expanded from macro '__write_64bit_c0_register' __write_64bit_c0_split(register, sel, value); \ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~ ./arch/mips/include/asm/mipsregs.h:1498:13: note: expanded from macro '__write_64bit_c0_split' : "r,0" (val)); \ ^~~ We can both fix this build failure & simplify the code somewhat by assigning the __tmp variable with the input value in C prior to our inline assembly, and then using a single read-write output operand (ie. a constraint beginning with +) to provide this value to our assembly. Signed-off-by: Paul Burton <paul.burton@mips.com>
2018-08-07x86/mm/pti: Fix 32 bit PCID checkJoerg Roedel
The check uses the wrong operator and causes false positive warnings in the kernel log on some systems. Fixes: 5e8105950a8b3 ('x86/mm/pti: Add Warning when booting on a PCID capable CPU') Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: linux-mm@kvack.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Waiman Long <llong@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca> Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1533637471-30953-2-git-send-email-joro@8bytes.org
2018-08-07xen: don't use privcmd_call() from xen_mc_flush()Juergen Gross
Using privcmd_call() for a singleton multicall seems to be wrong, as privcmd_call() is using stac()/clac() to enable hypervisor access to Linux user space. Even if currently not a problem (pv domains can't use SMAP while HVM and PVH domains can't use multicalls) things might change when PVH dom0 support is added to the kernel. Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
2018-08-08powerpc/powernv/opal: Use standard interrupts property when availableBenjamin Herrenschmidt
For (bad) historical reasons, OPAL used to create a non-standard pair of properties "opal-interrupts" and "opal-interrupts-names" for representing the list of interrupts it wants Linux to request on its behalf. Among other issues, the opal-interrupts doesn't have a way to carry the type of interrupts, and they were assumed to be all level sensitive. This is wrong on some recent systems where some of them are edge sensitive causing warnings in the XIVE code and possible misbehaviours if they need to be retriggered (typically the NPU2 TCE error interrupts). This makes Linux switch to using the standard "interrupts" and "interrupt-names" properties instead when they are available, using standard of_irq helpers, which can carry all the desired type information. Newer versions of OPAL will generate those properties in addition to the legacy ones. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Fixup prefix logic to check strlen(r->name). Reinstate setting of start = 0 in opal_event_shutdown() to avoid double free warnings] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc: Allow CPU selection of e300core variantsChristophe Leroy
GCC supports -mcpu=e300c2 and -mcpu=e300c3 This patch gives the opportunity to tune kernel to one of those two types. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc: Allow CPU selection also on PPC32Christophe Leroy
This patch extends to PPC32 the capability to select the exact CPU type. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc: Make CPU selection logic generic in MakefileChristophe Leroy
At the time being, when adding a new CPU for selection, both Kconfig.cputype and Makefile have to be modified. This patch moves into Kconfig.cputype the name of the CPU to me passed to the -mcpu= argument. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Rename the option to TARGET_CPU to echo the gcc documentation] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/Makefiles: Convert ifeq to ifdef where possibleRodrigo R. Galvao
In Makefiles if we're testing a CONFIG_FOO symbol for equality with 'y' we can instead just use ifdef. The latter reads easily, so convert to it where possible. Signed-off-by: Rodrigo R. Galvao <rosattig@linux.vnet.ibm.com> Reviewed-by: Mauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64: Copy as much as possible in __copy_tofrom_userPaul Mackerras
In __copy_tofrom_user, if we encounter an exception on a store, we stop copying and return the number of bytes not copied. However, if the store is wider than one byte and is to an unaligned address, it is possible that the store operand overlaps a page boundary and the exception occurred on the latter part of the store operand, meaning that it would be possible to copy a few more bytes. Since copy_to_user is generally expected to copy as much as possible, it would be better to copy those extra few bytes. This adds code to do that. Since this edge case is not performance-critical, the code has been written to be compact rather than as fast as possible. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08selftests/powerpc/64: Test all paths through copy routinesPaul Mackerras
The hand-coded assembler 64-bit copy routines include feature sections that select one code path or another depending on which CPU we are executing on. The self-tests for these copy routines end up testing just one path. This adds a mechanism for selecting any desired code path at compile time, and makes 2 or 3 versions of each test, each using a different code path, so as to cover all the possible paths. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> [mpe: Add -mcpu=power4 to CFLAGS for older compilers] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64: Make exception table clearer in __copy_tofrom_user_basePaul Mackerras
This aims to make the generation of exception table entries for the loads and stores in __copy_tofrom_user_base clearer and easier to verify. Instead of having a series of local labels on the loads and stores, with a series of corresponding labels later for the exception handlers, we now use macros to generate exception table entries at the point of each load and store that could potentially trap. We do this with the macros lex (load exception) and stex (store exception). These macros are used right before the load or store to which they apply. Some complexity is introduced by the fact that we have some more work to do after hitting an exception, because we need to calculate and return the number of bytes not copied. The code uses r3 as the current pointer into the destination buffer, that is, the address of the first byte of the destination that has not been modified. However, at various points in the copy loops, r3 can be 4, 8, 16 or 24 bytes behind that point. To express this offset in an understandable way, we define a symbol r3_offset which is updated at various points so that it equal to the difference between the address of the first unmodified byte of the destination and the value in r3. (In fact it only needs to be accurate at the point of each lex or stex macro invocation.) The rules for updating r3_offset are as follows: * It starts out at 0 * An addi r3,r3,N instruction decreases r3_offset by N * A store instruction (stb, sth, stw, std) to N(r3) increases r3_offset by the width of the store (1, 2, 4, 8) * A store with update instruction (stbu, sthu, stwu, stdu) to N(r3) sets r3_offset to the width of the store. There is some trickiness to the way that the lex and stex macros and the associated exception handlers work. I would have liked to use the current value of r3_offset in the name of the symbol used as the exception handler, as in ".Lld_exc_$(r3_offset)" and then have symbols .Lld_exc_0, .Lld_exc_8, .Lld_exc_16 etc. corresponding to the offsets that needed to be added to r3. However, I couldn't see a way to do that with gas. Instead, the exception handler address is .Lld_exc - r3_offset or .Lst_exc - r3_offset, that is, the distance ahead of .Lld_exc/.Lst_exc that we start executing is equal to the amount that we need to add to r3. This works because r3_offset is always a small multiple of 4, and our instructions are 4 bytes long. This means that before .Lld_exc and .Lst_exc, we have a sequence of instructions that increments r3 by 4, 8, 16 or 24 depending on where we start. The sequence increments r3 by 4 per instruction (on average). We also replace the exception table for the 4k copy loop by a macro per load or store. These loads and stores all use exactly the same exception handler, which simply resets the argument registers r3, r4 and r5 to there original values and re-does the whole copy using the slower loop. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/powermac: of_node_put() is not needed after iteratorzhong jiang
for_each_node_by_name() iterators only exit normally when the loop cursor is NULL, So there is no need to call of_node_put(). Signed-off-by: zhong jiang <zhongjiang@huawei.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08crypto/nx: Initialize 842 high and normal RxFIFO control registersHaren Myneni
NX increments readOffset by FIFO size in receive FIFO control register when CRB is read. But the index in RxFIFO has to match with the corresponding entry in FIFO maintained by VAS in kernel. Otherwise NX may be processing incorrect CRBs and can cause CRB timeout. VAS FIFO offset is 0 when the receive window is opened during initialization. When the module is reloaded or in kexec boot, readOffset in FIFO control register may not match with VAS entry. This patch adds nx_coproc_init OPAL call to reset readOffset and queued entries in FIFO control register for both high and normal FIFOs. Signed-off-by: Haren Myneni <haren@us.ibm.com> [mpe: Fixup uninitialized variable warning] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/powernv: Export opal_check_token symbolHaren Myneni
Export opal_check_token symbol for modules to check the availability of OPAL calls before using them. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/platforms/85xx: fix t1042rdb_diu.c build errors & warningRandy Dunlap
Fix build errors and warnings in t1042rdb_diu.c by adding header files and MODULE_LICENSE(). ../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: data definition has no type or storage class early_initcall(t1042rdb_diu_init); ../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: error: type defaults to 'int' in declaration of 'early_initcall' [-Werror=implicit-int] ../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: parameter names (without types) in function declaration and WARNING: modpost: missing MODULE_LICENSE() in arch/powerpc/platforms/85xx/t1042rdb_diu.o Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Scott Wood <oss@buserror.net> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/perf: Remove sched_task function defined for thread-imcAnju T Sudhakar
Call trace observed while running perf-fuzzer: CPU: 43 PID: 9088 Comm: perf_fuzzer Not tainted 4.13.0-32-generic #35~lp1746225 task: c000003f776ac900 task.stack: c000003f77728000 NIP: c000000000299b70 LR: c0000000002a4534 CTR: c00000000029bb80 REGS: c000003f7772b760 TRAP: 0700 Not tainted (4.13.0-32-generic) MSR: 900000000282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24008822 XER: 00000000 CFAR: c000000000299a70 SOFTE: 0 GPR00: c0000000002a4534 c000003f7772b9e0 c000000001606200 c000003fef858908 GPR04: c000003f776ac900 0000000000000001 ffffffffffffffff 0000003fee730000 GPR08: 0000000000000000 0000000000000000 c0000000011220d8 0000000000000002 GPR12: c00000000029bb80 c000000007a3d900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c000003f776ad090 c000000000c71354 GPR24: c000003fef716780 0000003fee730000 c000003fe69d4200 c000003f776ad330 GPR28: c0000000011220d8 0000000000000001 c0000000014c6108 c000003fef858900 NIP [c000000000299b70] perf_pmu_sched_task+0x170/0x180 LR [c0000000002a4534] __perf_event_task_sched_in+0xc4/0x230 Call Trace: perf_iterate_sb+0x158/0x2a0 (unreliable) __perf_event_task_sched_in+0xc4/0x230 finish_task_switch+0x21c/0x310 __schedule+0x304/0xb80 schedule+0x40/0xc0 do_wait+0x254/0x2e0 kernel_wait4+0xa0/0x1a0 SyS_wait4+0x64/0xc0 system_call+0x58/0x6c Instruction dump: 3beafea0 7faa4800 409eff18 e8010060 eb610028 ebc10040 7c0803a6 38210050 eb81ffe0 eba1ffe8 ebe1fff8 4e800020 <0fe00000> 4bffffbc 60000000 60420000 ---[ end trace 8c46856d314c1811 ]--- The context switch call-backs for thread-imc are defined in sched_task function. So when thread-imc events are grouped with software pmu events, perf_pmu_sched_task hits the WARN_ON_ONCE condition, since software PMUs are assumed not to have a sched_task defined. Patch to move the thread_imc enable/disable opal call back from sched_task to event_[add/del] function Fixes: f74c89bd80fb ("powerpc/perf: Add thread IMC PMU support") Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Tested-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64s: Fix page table fragment refcount race vs speculative referencesNicholas Piggin
The page table fragment allocator uses the main page refcount racily with respect to speculative references. A customer observed a BUG due to page table page refcount underflow in the fragment allocator. This can be caused by the fragment allocator set_page_count stomping on a speculative reference, and then the speculative failure handler decrements the new reference, and the underflow eventually pops when the page tables are freed. Fix this by using a dedicated field in the struct page for the page table fragment allocator. Fixes: 5c1f6ee9a31c ("powerpc: Reduce PTE table memory wastage") Cc: stable@vger.kernel.org # v3.10+ Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/pasemi: Use pr_err/pr_warn... for kernel messagesDarren Stevens
Pasemi code still uses printk(KERN_ERR/KERN_WARN ... change these to pr_err(, pr_warn(... to match other powerpc arch code. No functional changes. Signed-off-by: Darren Stevens <darren@stevens-zone.net> [mpe: Unsplit some strings while we're at it] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/traps: Show instructions on exceptionsMurilo Opsfelder Araujo
Call show_user_instructions() in arch/powerpc/kernel/traps.c to dump instructions at faulty location, useful to debugging. Before this patch, an unhandled signal message looked like: pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 code 2 in pandafault[10000000+10000] After this patch, it looks like: pandafault[10524]: segfault (11) at 100007d0 nip 1000061c lr 7fffbd295100 code 2 in pandafault[10000000+10000] pandafault[10524]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe pandafault[10524]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040 Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc: Add show_user_instructions()Murilo Opsfelder Araujo
show_user_instructions() is a slightly modified version of show_instructions() that allows userspace instruction dump. This will be useful within show_signal_msg() to dump userspace instructions of the faulty location. Here is a sample of what show_user_instructions() outputs: pandafault[10850]: code: 4bfffeec 4bfffee8 3c401002 38427f00 fbe1fff8 f821ffc1 7c3f0b78 3d22fffe pandafault[10850]: code: 392988d0 f93f0020 e93f0020 39400048 <99490000> 39200000 7d234b78 383f0040 The current->comm and current->pid printed can serve as a glue that links the instructions dump to its originator, allowing messages to be interleaved in the logs. Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/traps: Print VMA for unhandled signalsMurilo Opsfelder Araujo
This adds VMA address in the message printed for unhandled signals, similarly to what other architectures, like x86, print. Before this patch, a page fault looked like: pandafault[61470]: unhandled signal 11 at 100007d0 nip 1000061c lr 7fff8d185100 code 2 After this patch, a page fault looks like: pandafault[6303]: segfault 11 at 100007d0 nip 1000061c lr 7fff93c55100 code 2 in pandafault[10000000+10000] Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/traps: Use %lx format in show_signal_msg()Murilo Opsfelder Araujo
Use %lx format to print registers. This avoids having two different formats and avoids checking for MSR_64BIT, improving readability of the function. Even though we could have used %px, which is functionally equivalent to %lx as per Documentation/core-api/printk-formats.rst, it is not semantically correct because the data printed are not pointers. And using %px requires casting data to (void *). Besides that, %lx matches the format used in show_regs(). Before this patch: pandafault[4808]: unhandled signal 11 at 0000000010000718 nip 0000000010000574 lr 00007fff935e7a6c code 2 After this patch: pandafault[4732]: unhandled signal 11 at 10000718 nip 10000574 lr 7fff86697a6c code 2 Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/traps: Use an explicit ratelimit state for show_signal_msg()Murilo Opsfelder Araujo
Replace printk_ratelimited() by printk() and a default rate limit burst to limit displaying unhandled signals messages. This will allow us to call print_vma_addr() in a future patch, which does not work with printk_ratelimited(). Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/traps: Print unhandled signals in a separate functionMurilo Opsfelder Araujo
Isolate the logic of printing unhandled signals out of _exception_pkey(). No functional change, only code rearrangement. Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64s: Make rfi_flush_fallback a little more robustMichael Ellerman
Because rfi_flush_fallback runs immediately before the return to userspace it currently runs with the user r1 (stack pointer). This means if we oops in there we will report a bad kernel stack pointer in the exception entry path, eg: Bad kernel stack pointer 7ffff7150e40 at c0000000000023b4 Oops: Bad kernel stack pointer, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1246 Comm: klogd Not tainted 4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3 #7 NIP: c0000000000023b4 LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000fffe7d40 TRAP: 4100 Not tainted (4.18.0-rc2-gcc-7.3.1-00175-g0443f8a69ba3) MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: c0000000f1e66a80 GPR00: 0000000002000000 00007ffff7150e40 00007fff93a99900 0000000000000020 ... NIP [c0000000000023b4] rfi_flush_fallback+0x34/0x80 LR [0000000010053e00] 0x10053e00 Although the NIP tells us where we were, and the TRAP number tells us what happened, it would still be nicer if we could report the actual exception rather than barfing about the stack pointer. We an do that fairly simply by loading the kernel stack pointer on entry and restoring the user value before returning. That way we see a regular oops such as: Unrecoverable exception 4100 at c00000000000239c Oops: Unrecoverable exception, sig: 6 [#1] LE SMP NR_CPUS=32 NUMA PowerNV Modules linked in: CPU: 0 PID: 1251 Comm: klogd Not tainted 4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty #40 NIP: c00000000000239c LR: 0000000010053e00 CTR: 0000000000000040 REGS: c0000000f1e17bb0 TRAP: 4100 Not tainted (4.18.0-rc3-gcc-7.3.1-00097-g4ebfcac65acd-dirty) MSR: 9000000002803031 <SF,HV,VEC,VSX,FP,ME,IR,DR,LE> CR: 44000442 XER: 20000000 CFAR: c00000000000bac8 IRQMASK: 0 ... NIP [c00000000000239c] rfi_flush_fallback+0x3c/0x80 LR [0000000010053e00] 0x10053e00 Call Trace: [c0000000f1e17e30] [c00000000000b9e4] system_call+0x5c/0x70 (unreliable) Note this shouldn't make the kernel stack pointer vulnerable to a meltdown attack, because it should be flushed from the cache before we return to userspace. The user r1 value will be in the cache, because we load it in the return path, but that is harmless. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-08-08powerpc/powernv: Query firmware for count cache flush settingsMichael Ellerman
Look for fw-features properties to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/pseries: Query hypervisor for count cache flush settingsMichael Ellerman
Use the existing hypercall to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64s: Add support for software count cache flushMichael Ellerman
Some CPU revisions support a mode where the count cache needs to be flushed by software on context switch. Additionally some revisions may have a hardware accelerated flush, in which case the software flush sequence can be shortened. If we detect the appropriate flag from firmware we patch a branch into _switch() which takes us to a count cache flush sequence. That sequence in turn may be patched to return early if we detect that the CPU supports accelerating the flush sequence in hardware. Add debugfs support for reporting the state of the flush, as well as runtime disabling it. And modify the spectre_v2 sysfs file to report the state of the software flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64s: Add new security feature flags for count cache flushMichael Ellerman
Add security feature flags to indicate the need for software to flush the count cache on context switch, and for the presence of a hardware assisted count cache flush. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/asm: Add a patch_site macro & helpers for patching instructionsMichael Ellerman
Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platformsDiana Craciun
Used barrier_nospec to sanitize the syscall table. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book3EDiana Craciun
Implement the barrier_nospec as a isync;sync instruction sequence. The implementation uses the infrastructure built for BOOK3S 64. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64: Make meltdown reporting Book3S 64 specificDiana Craciun
In a subsequent patch we will enable building security.c for Book3E. However the NXP platforms are not vulnerable to Meltdown, so make the Meltdown vulnerability reporting PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> [mpe: Split out of larger patch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64: Call setup_barrier_nospec() from setup_arch()Michael Ellerman
Currently we require platform code to call setup_barrier_nospec(). But if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case then we can call it in setup_arch(). Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64: Add CONFIG_PPC_BARRIER_NOSPECMichael Ellerman
Add a config symbol to encode which platforms support the barrier_nospec speculation barrier. Currently this is just Book3S 64 but we will add Book3E in a future patch. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-08powerpc/64: Make stf barrier PPC_BOOK3S_64 specific.Diana Craciun
NXP Book3E platforms are not vulnerable to speculative store bypass, so make the mitigations PPC_BOOK3S_64 specific. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07um: clean up archheaders recipeMasahiro Yamada
Now that '%asm-generic' is added to no-dot-config-targets, 'make asm-generic' does not include the kernel configuration. You can simply do 'make asm-generic' in the recursed top Makefile without bothering syncconfig. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Richard Weinberger <richard@nod.at>
2018-08-07um: fix parallel building with O= optionMasahiro Yamada
Randy Dunlap reports UML occasionally fails to build with -j<N> and O=<builddir> options. make[1]: Entering directory '/home/rdunlap/mmotm-2018-0802-1529/UM64' UPD include/generated/uapi/linux/version.h WRAP arch/x86/include/generated/asm/dma-contiguous.h WRAP arch/x86/include/generated/asm/export.h WRAP arch/x86/include/generated/asm/early_ioremap.h WRAP arch/x86/include/generated/asm/mcs_spinlock.h WRAP arch/x86/include/generated/asm/mm-arch-hooks.h WRAP arch/x86/include/generated/uapi/asm/bpf_perf_event.h WRAP arch/x86/include/generated/uapi/asm/poll.h GEN ./Makefile make[2]: *** No rule to make target 'archheaders'. Stop. arch/um/Makefile:119: recipe for target 'archheaders' failed make[1]: *** [archheaders] Error 2 make[1]: *** Waiting for unfinished jobs.... UPD include/config/kernel.release make[1]: *** wait: No child processes. Stop. Makefile:146: recipe for target 'sub-make' failed make: *** [sub-make] Error 2 The cause of the problem is the use of '$(MAKE) KBUILD_SRC=', which recurses to the top Makefile via the $(objtree)/Makefile generated by scripts/mkmakefile. When you run "make -j<N> O=<builddir> ARCH=um", Make can execute 'archheaders' and 'outputmakefile' targets simultaneously because there is no dependency between them. If it happens, $(Q)$(MAKE) KBUILD_SRC= ARCH=$(HEADER_ARCH) archheaders ... tries to run $(objtree)/Makefile that is being updated. The correct way for the recursion is $(Q)$(MAKE) -f $(srctree)/Makefile ARCH=$(HEADER_ARCH) archheaders ..., which does not rely on the generated Makefile. Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Tested-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Richard Weinberger <richard@nod.at>
2018-08-07powerpc/64: Disable the speculation barrier from the command lineDiana Craciun
The speculation barrier can be disabled from the command line with the parameter: "nospectre_v1". Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Don't use __MASKABLE_EXCEPTION unnecessarilyMichael Ellerman
We only need to use __MASKABLE_EXCEPTION in one of the four cases for hardware interrupt, so use the helper macros in the other cases. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Drop unused loc parameter to MASKABLE_EXCEPTION macrosMichael Ellerman
We pass the "loc" (location) parameter to MASKABLE_EXCEPTION and friends, but it's not used, so drop it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Remove PSERIES naming from the MASKABLE macrosMichael Ellerman
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Drop _MASKABLE_RELON_EXCEPTION_PSERIES()Michael Ellerman
_MASKABLE_RELON_EXCEPTION_PSERIES() does nothing useful, update all callers to use __MASKABLE_RELON_EXCEPTION_PSERIES() directly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Drop _MASKABLE_EXCEPTION_PSERIES()Michael Ellerman
_MASKABLE_EXCEPTION_PSERIES() does nothing useful, update all callers to use __MASKABLE_EXCEPTION_PSERIES() directly. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-07powerpc/64s: Rename EXCEPTION_PROLOG_PSERIES to EXCEPTION_PROLOGMichael Ellerman
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>