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2023-02-06x86/asm: Fix an assembler warning with current binutilsMikulas Patocka1-1/+1
commit 55d235361fccef573990dfa5724ab453866e7816 upstream. Fix a warning: "found `movsd'; assuming `movsl' was meant" Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14x86/delay: Fix the wrong asm constraint in delay_loop()Ammar Faizi1-2/+2
[ Upstream commit b86eb74098a92afd789da02699b4b0dd3f73b889 ] The asm constraint does not reflect the fact that the asm statement can modify the value of the local variable loops. Which it does. Specifying the wrong constraint may lead to undefined behavior, it may clobber random stuff (e.g. local variable, important temporary value in regs, etc.). This is especially dangerous when the compiler decides to inline the function and since it doesn't know that the value gets modified, it might decide to use it from a register directly without reloading it. Change the constraint to "+a" to denote that the first argument is an input and an output argument. [ bp: Fix typo, massage commit message. ] Fixes: e01b70ef3eb3 ("x86: fix bug in arch/i386/lib/delay.c file, delay_loop function") Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20220329104705.65256-2-ammarfaizi2@gnuweeb.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-12x86: __memcpy_flushcache: fix wrong alignment if size > 2^32Mikulas Patocka1-1/+1
[ Upstream commit a6823e4e360fe975bd3da4ab156df7c74c8b07f3 ] The first "if" condition in __memcpy_flushcache is supposed to align the "dest" variable to 8 bytes and copy data up to this alignment. However, this condition may misbehave if "size" is greater than 4GiB. The statement min_t(unsigned, size, ALIGN(dest, 8) - dest); casts both arguments to unsigned int and selects the smaller one. However, the cast truncates high bits in "size" and it results in misbehavior. For example: suppose that size == 0x100000001, dest == 0x200000002 min_t(unsigned, size, ALIGN(dest, 8) - dest) == min_t(0x1, 0xe) == 0x1; ... dest += 0x1; so we copy just one byte "and" dest remains unaligned. This patch fixes the bug by replacing unsigned with size_t. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypesArnd Bergmann1-2/+2
commit 396a66aa1172ef2b78c21651f59b40b87b2e5e1e upstream. gcc-11 warns about mismatched prototypes here: arch/x86/lib/msr-smp.c:255:51: error: argument 2 of type ‘u32 *’ {aka ‘unsigned int *’} declared as a pointer [-Werror=array-parameter=] 255 | int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs) | ~~~~~^~~~ arch/x86/include/asm/msr.h:347:50: note: previously declared as an array ‘u32[8]’ {aka ‘unsigned int[8]’} GCC is right here - fix up the types. [ mingo: Twiddled the changelog. ] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210322164541.912261-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.SFangrui Song3-8/+8
commit 4d6ffa27b8e5116c0abb318790fd01d4e12d75e6 upstream. Commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") added .weak directives to arch/x86/lib/mem*_64.S instead of changing the existing ENTRY macros to WEAK. This can lead to the assembly snippet .weak memcpy ... .globl memcpy which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since https://reviews.llvm.org/D90108) will error on such an overridden symbol binding. Commit ef1e03152cb0 ("x86/asm: Make some functions local") changed ENTRY in arch/x86/lib/memcpy_64.S to SYM_FUNC_START_LOCAL, which was ineffective due to the preceding .weak directive. Use the appropriate SYM_FUNC_START_WEAK instead. Fixes: 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") Fixes: ef1e03152cb0 ("x86/asm: Make some functions local") Reported-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103012358.168682-1-maskray@google.com [nd: backport due to missing commit e9b9d020c487 ("x86/asm: Annotate aliases") commit ffedeeb780dc ("linkage: Introduce new macros for assembler symbols")] Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-11x86/insn-eval: Use new for_each_insn_prefix() macro to loop over prefixes bytesMasami Hiramatsu1-2/+3
commit 12cb908a11b2544b5f53e9af856e6b6a90ed5533 upstream Since insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a prefix is repeated, the proper check must be insn.prefixes.bytes[i] != 0 and i < 4 instead of using insn.prefixes.nbytes. Use the new for_each_insn_prefix() macro which does it correctly. Debugged by Kees Cook <keescook@chromium.org>. [ bp: Massage commit message. ] Fixes: 32d0b95300db ("x86/insn-eval: Add utility functions to get segment selector") Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/160697104969.3146288.16329307586428270032.stgit@devnote2 [sudip: adjust context] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01arch/x86/lib/usercopy_64.c: fix __copy_user_flushcache() cache writebackMikulas Patocka1-1/+1
commit a1cd6c2ae47ee10ff21e62475685d5b399e2ed4a upstream. If we copy less than 8 bytes and if the destination crosses a cache line, __copy_user_flushcache would invalidate only the first cache line. This patch makes it invalidate the second cache line as well. Fixes: 0aed55af88345b ("x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass operations") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Dan Williams <dan.j.wiilliams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2009161451140.21915@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-01x86/asm/64: Align start of __clear_user() loop to 16-bytesMatt Fleming1-0/+1
commit bb5570ad3b54e7930997aec76ab68256d5236d94 upstream. 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-24x86/decoder: Add TEST opcode to Group3-2Masami Hiramatsu1-1/+1
[ Upstream commit 8b7e20a7ba54836076ff35a28349dabea4cec48f ] Add TEST opcode to Group3-2 reg=001b as same as Group3-1 does. Commit 12a78d43de76 ("x86/decoder: Add new TEST instruction pattern") added a TEST opcode assignment to f6 XX/001/XXX (Group 3-1), but did not add f7 XX/001/XXX (Group 3-2). Actually, this TEST opcode variant (ModRM.reg /1) is not described in the Intel SDM Vol2 but in AMD64 Architecture Programmer's Manual Vol.3, Appendix A.2 Table A-6. ModRM.reg Extensions for the Primary Opcode Map. Without this fix, Randy found a warning by insn_decoder_test related to this issue as below. HOSTCC arch/x86/tools/insn_decoder_test HOSTCC arch/x86/tools/insn_sanity TEST posttest arch/x86/tools/insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this. arch/x86/tools/insn_decoder_test: warning: ffffffff81000bf1: f7 0b 00 01 08 00 testl $0x80100,(%rbx) arch/x86/tools/insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 2 arch/x86/tools/insn_decoder_test: warning: Decoded and checked 11913894 instructions with 1 failures TEST posttest arch/x86/tools/insn_sanity: Success: decoded and checked 1000000 random instructions with 0 errors (seed:0x871ce29c) To fix this error, add the TEST opcode according to AMD64 APM Vol.3. [ bp: Massage commit message. ] Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lkml.kernel.org/r/157966631413.9580.10311036595431878351.stgit@devnote2 Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31x86/insn: Add some Intel instructions to the opcode mapAdrian Hunter1-6/+12
[ Upstream commit b980be189c9badba50634671e2303e92bf28e35a ] Add to the opcode map the following instructions: cldemote tpause umonitor umwait movdiri movdir64b enqcmd enqcmds encls enclu enclv pconfig wbnoinvd For information about the instructions, refer Intel SDM May 2019 (325462-070US) and Intel Architecture Instruction Set Extensions May 2019 (319433-037). The instruction decoding can be tested using the perf tools' "x86 instruction decoder - new instructions" test as folllows: $ perf test -v "new " 2>&1 | grep -i cldemote Decoded ok: 0f 1c 00 cldemote (%eax) Decoded ok: 0f 1c 05 78 56 34 12 cldemote 0x12345678 Decoded ok: 0f 1c 84 c8 78 56 34 12 cldemote 0x12345678(%eax,%ecx,8) Decoded ok: 0f 1c 00 cldemote (%rax) Decoded ok: 41 0f 1c 00 cldemote (%r8) Decoded ok: 0f 1c 04 25 78 56 34 12 cldemote 0x12345678 Decoded ok: 0f 1c 84 c8 78 56 34 12 cldemote 0x12345678(%rax,%rcx,8) Decoded ok: 41 0f 1c 84 c8 78 56 34 12 cldemote 0x12345678(%r8,%rcx,8) $ perf test -v "new " 2>&1 | grep -i tpause Decoded ok: 66 0f ae f3 tpause %ebx Decoded ok: 66 0f ae f3 tpause %ebx Decoded ok: 66 41 0f ae f0 tpause %r8d $ perf test -v "new " 2>&1 | grep -i umonitor Decoded ok: 67 f3 0f ae f0 umonitor %ax Decoded ok: f3 0f ae f0 umonitor %eax Decoded ok: 67 f3 0f ae f0 umonitor %eax Decoded ok: f3 0f ae f0 umonitor %rax Decoded ok: 67 f3 41 0f ae f0 umonitor %r8d $ perf test -v "new " 2>&1 | grep -i umwait Decoded ok: f2 0f ae f0 umwait %eax Decoded ok: f2 0f ae f0 umwait %eax Decoded ok: f2 41 0f ae f0 umwait %r8d $ perf test -v "new " 2>&1 | grep -i movdiri Decoded ok: 0f 38 f9 03 movdiri %eax,(%ebx) Decoded ok: 0f 38 f9 88 78 56 34 12 movdiri %ecx,0x12345678(%eax) Decoded ok: 48 0f 38 f9 03 movdiri %rax,(%rbx) Decoded ok: 48 0f 38 f9 88 78 56 34 12 movdiri %rcx,0x12345678(%rax) $ perf test -v "new " 2>&1 | grep -i movdir64b Decoded ok: 66 0f 38 f8 18 movdir64b (%eax),%ebx Decoded ok: 66 0f 38 f8 88 78 56 34 12 movdir64b 0x12345678(%eax),%ecx Decoded ok: 67 66 0f 38 f8 1c movdir64b (%si),%bx Decoded ok: 67 66 0f 38 f8 8c 34 12 movdir64b 0x1234(%si),%cx Decoded ok: 66 0f 38 f8 18 movdir64b (%rax),%rbx Decoded ok: 66 0f 38 f8 88 78 56 34 12 movdir64b 0x12345678(%rax),%rcx Decoded ok: 67 66 0f 38 f8 18 movdir64b (%eax),%ebx Decoded ok: 67 66 0f 38 f8 88 78 56 34 12 movdir64b 0x12345678(%eax),%ecx $ perf test -v "new " 2>&1 | grep -i enqcmd Decoded ok: f2 0f 38 f8 18 enqcmd (%eax),%ebx Decoded ok: f2 0f 38 f8 88 78 56 34 12 enqcmd 0x12345678(%eax),%ecx Decoded ok: 67 f2 0f 38 f8 1c enqcmd (%si),%bx Decoded ok: 67 f2 0f 38 f8 8c 34 12 enqcmd 0x1234(%si),%cx Decoded ok: f3 0f 38 f8 18 enqcmds (%eax),%ebx Decoded ok: f3 0f 38 f8 88 78 56 34 12 enqcmds 0x12345678(%eax),%ecx Decoded ok: 67 f3 0f 38 f8 1c enqcmds (%si),%bx Decoded ok: 67 f3 0f 38 f8 8c 34 12 enqcmds 0x1234(%si),%cx Decoded ok: f2 0f 38 f8 18 enqcmd (%rax),%rbx Decoded ok: f2 0f 38 f8 88 78 56 34 12 enqcmd 0x12345678(%rax),%rcx Decoded ok: 67 f2 0f 38 f8 18 enqcmd (%eax),%ebx Decoded ok: 67 f2 0f 38 f8 88 78 56 34 12 enqcmd 0x12345678(%eax),%ecx Decoded ok: f3 0f 38 f8 18 enqcmds (%rax),%rbx Decoded ok: f3 0f 38 f8 88 78 56 34 12 enqcmds 0x12345678(%rax),%rcx Decoded ok: 67 f3 0f 38 f8 18 enqcmds (%eax),%ebx Decoded ok: 67 f3 0f 38 f8 88 78 56 34 12 enqcmds 0x12345678(%eax),%ecx $ perf test -v "new " 2>&1 | grep -i enqcmds Decoded ok: f3 0f 38 f8 18 enqcmds (%eax),%ebx Decoded ok: f3 0f 38 f8 88 78 56 34 12 enqcmds 0x12345678(%eax),%ecx Decoded ok: 67 f3 0f 38 f8 1c enqcmds (%si),%bx Decoded ok: 67 f3 0f 38 f8 8c 34 12 enqcmds 0x1234(%si),%cx Decoded ok: f3 0f 38 f8 18 enqcmds (%rax),%rbx Decoded ok: f3 0f 38 f8 88 78 56 34 12 enqcmds 0x12345678(%rax),%rcx Decoded ok: 67 f3 0f 38 f8 18 enqcmds (%eax),%ebx Decoded ok: 67 f3 0f 38 f8 88 78 56 34 12 enqcmds 0x12345678(%eax),%ecx $ perf test -v "new " 2>&1 | grep -i encls Decoded ok: 0f 01 cf encls Decoded ok: 0f 01 cf encls $ perf test -v "new " 2>&1 | grep -i enclu Decoded ok: 0f 01 d7 enclu Decoded ok: 0f 01 d7 enclu $ perf test -v "new " 2>&1 | grep -i enclv Decoded ok: 0f 01 c0 enclv Decoded ok: 0f 01 c0 enclv $ perf test -v "new " 2>&1 | grep -i pconfig Decoded ok: 0f 01 c5 pconfig Decoded ok: 0f 01 c5 pconfig $ perf test -v "new " 2>&1 | grep -i wbnoinvd Decoded ok: f3 0f 09 wbnoinvd Decoded ok: f3 0f 09 wbnoinvd Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Link: http://lore.kernel.org/lkml/20191115135447.6519-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-17x86/asm: Fix MWAITX C-state hint valueJanakarajan Natarajan1-2/+2
commit 454de1e7d970d6bc567686052329e4814842867c upstream. As per "AMD64 Architecture Programmer's Manual Volume 3: General-Purpose and System Instructions", MWAITX EAX[7:4]+1 specifies the optional hint of the optimized C-state. For C0 state, EAX[7:4] should be set to 0xf. Currently, a value of 0xf is set for EAX[3:0] instead of EAX[7:4]. Fix this by changing MWAITX_DISABLE_CSTATES from 0xf to 0xf0. This hasn't had any implications so far because setting reserved bits in EAX is simply ignored by the CPU. [ bp: Fixup comment in delay_mwaitx() and massage. ] Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20191007190011.4859-1-Janakarajan.Natarajan@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-29x86/lib/cpu: Address missing prototypes warningValdis Klētnieks1-0/+1
[ Upstream commit 04f5bda84b0712d6f172556a7e8dca9ded5e73b9 ] When building with W=1, warnings about missing prototypes are emitted: CC arch/x86/lib/cpu.o arch/x86/lib/cpu.c:5:14: warning: no previous prototype for 'x86_family' [-Wmissing-prototypes] 5 | unsigned int x86_family(unsigned int sig) | ^~~~~~~~~~ arch/x86/lib/cpu.c:18:14: warning: no previous prototype for 'x86_model' [-Wmissing-prototypes] 18 | unsigned int x86_model(unsigned int sig) | ^~~~~~~~~ arch/x86/lib/cpu.c:33:14: warning: no previous prototype for 'x86_stepping' [-Wmissing-prototypes] 33 | unsigned int x86_stepping(unsigned int sig) | ^~~~~~~~~~~~ Add the proper include file so the prototypes are there. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/42513.1565234837@turing-police Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-11x86/insn-eval: Fix use-after-free access to LDT entryJann Horn1-23/+24
commit de9f869616dd95e95c00bdd6b0fcd3421e8a4323 upstream. get_desc() computes a pointer into the LDT while holding a lock that protects the LDT from being freed, but then drops the lock and returns the (now potentially dangling) pointer to its caller. Fix it by giving the caller a copy of the LDT entry instead. Fixes: 670f928ba09b ("x86/insn-eval: Add utility function to get segment descriptor") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31x86/uaccess: Fix up the fixupPeter Zijlstra1-1/+2
[ Upstream commit b69656fa7ea2f75e47d7bd5b9430359fa46488af ] New tooling got confused about this: arch/x86/lib/memcpy_64.o: warning: objtool: .fixup+0x7: return with UACCESS enabled While the code isn't wrong, it is tedious (if at all possible) to figure out what function a particular chunk of .fixup belongs to. This then confuses the objtool uaccess validation. Instead of returning directly from the .fixup, jump back into the right function. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-25x86/mm/mem_encrypt: Disable all instrumentation for early SME setupGary Hook1-0/+12
[ Upstream commit b51ce3744f115850166f3d6c292b9c8cb849ad4f ] Enablement of AMD's Secure Memory Encryption feature is determined very early after start_kernel() is entered. Part of this procedure involves scanning the command line for the parameter 'mem_encrypt'. To determine intended state, the function sme_enable() uses library functions cmdline_find_option() and strncmp(). Their use occurs early enough such that it cannot be assumed that any instrumentation subsystem is initialized. For example, making calls to a KASAN-instrumented function before KASAN is set up will result in the use of uninitialized memory and a boot failure. When AMD's SME support is enabled, conditionally disable instrumentation of these dependent functions in lib/string.c and arch/x86/lib/cmdline.c. [ bp: Get rid of intermediary nostackp var and cleanup whitespace. ] Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Reported-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Gary R Hook <gary.hook@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Boris Brezillon <bbrezillon@kernel.org> Cc: Coly Li <colyli@suse.de> Cc: "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: "luto@kernel.org" <luto@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: "mingo@redhat.com" <mingo@redhat.com> Cc: "peterz@infradead.org" <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/155657657552.7116.18363762932464011367.stgit@sosrh3.amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-31x86/kaslr: Fix incorrect i8254 outb() parametersDaniel Drake1-2/+2
commit 7e6fc2f50a3197d0e82d1c0e86282976c9e6c8a4 upstream. The outb() function takes parameters value and port, in that order. Fix the parameters used in the kalsr i8254 fallback code. Fixes: 5bfce5ef55cb ("x86, kaslr: Provide randomness functions") Signed-off-by: Daniel Drake <drake@endlessm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: hpa@zytor.com Cc: linux@endlessm.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190107034024.15005-1-drake@endlessm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-31x86/nmi: Fix NMI uaccess race against CR3 switchingAndy Lutomirski1-0/+5
A NMI can hit in the middle of context switching or in the middle of switch_mm_irqs_off(). In either case, CR3 might not match current->mm, which could cause copy_from_user_nmi() and friends to read the wrong memory. Fix it by adding a new nmi_uaccess_okay() helper and checking it in copy_from_user_nmi() and in __copy_from_user_nmi()'s callers. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Rik van Riel <riel@surriel.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/dd956eba16646fd0b15c3c0741269dfd84452dac.1535557289.git.luto@kernel.org
2018-07-03x86/asm/64: Use 32-bit XOR to zero registersJan Beulich1-1/+1
Some Intel CPUs don't recognize 64-bit XORs as zeroing idioms. Zeroing idioms don't require execution bandwidth, as they're being taken care of in the frontend (through register renaming). Use 32-bit XORs instead. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Alok Kataria <akataria@vmware.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: herbert@gondor.apana.org.au Cc: pavel@ucw.cz Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/5B39FF1A02000078001CFB54@prv1-mh.provo.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-09Merge tag 'libnvdimm-for-4.18' of ↵Linus Torvalds1-0/+10
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "This adds a user for the new 'bytes-remaining' updates to memcpy_mcsafe() that you already received through Ingo via the x86-dax- for-linus pull. Not included here, but still targeting this cycle, is support for handling memory media errors (poison) consumed via userspace dax mappings. Summary: - DAX broke a fundamental assumption of truncate of file mapped pages. The truncate path assumed that it is safe to disconnect a pinned page from a file and let the filesystem reclaim the physical block. With DAX the page is equivalent to the filesystem block. Introduce dax_layout_busy_page() to enable filesystems to wait for pinned DAX pages to be released. Without this wait a filesystem could allocate blocks under active device-DMA to a new file. - DAX arranges for the block layer to be bypassed and uses dax_direct_access() + copy_to_iter() to satisfy read(2) calls. However, the memcpy_mcsafe() facility is available through the pmem block driver. In order to safely handle media errors, via the DAX block-layer bypass, introduce copy_to_iter_mcsafe(). - Fix cache management policy relative to the ACPI NFIT Platform Capabilities Structure to properly elide cache flushes when they are not necessary. The table indicates whether CPU caches are power-fail protected. Clarify that a deep flush is always performed on REQ_{FUA,PREFLUSH} requests" * tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits) dax: Use dax_write_cache* helpers libnvdimm, pmem: Do not flush power-fail protected CPU caches libnvdimm, pmem: Unconditionally deep flush on *sync libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH acpi, nfit: Remove ecc_unit_size dax: dax_insert_mapping_entry always succeeds libnvdimm, e820: Register all pmem resources libnvdimm: Debug probe times linvdimm, pmem: Preserve read-only setting for pmem devices x86, nfit_test: Add unit test for memcpy_mcsafe() pmem: Switch to copy_to_iter_mcsafe() dax: Report bytes remaining in dax_iomap_actor() dax: Introduce a ->copy_to_iter dax operation uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation xfs, dax: introduce xfs_break_dax_layouts() xfs: prepare xfs_break_layouts() for another layout type xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL mm, fs, dax: handle layout changes to pinned dax mappings mm: fix __gup_device_huge vs unmap mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS ...
2018-06-05Merge branch 'x86-dax-for-linus' of ↵Linus Torvalds2-58/+65
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 dax updates from Ingo Molnar: "This contains x86 memcpy_mcsafe() fault handling improvements the nvdimm tree would like to make more use of" * 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe() x86/asm/memcpy_mcsafe: Add write-protection-fault handling x86/asm/memcpy_mcsafe: Return bytes remaining x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling x86/asm/memcpy_mcsafe: Remove loop unrolling
2018-05-23x86, nfit_test: Add unit test for memcpy_mcsafe()Dan Williams1-0/+10
Given the fact that the ACPI "EINJ" (error injection) facility is not universally available, implement software infrastructure to validate the memcpy_mcsafe() exception handling implementation. For each potential read exception point in memcpy_mcsafe(), inject a emulated exception point at the address identified by 'mcsafe_inject' variable. With this infrastructure implement a test to validate that the 'bytes remaining' calculation is correct for a range of various source buffer alignments. This code is compiled out by default. The CONFIG_MCSAFE_DEBUG configuration symbol needs to be manually enabled by editing Kconfig.debug. I.e. this functionality can not be accidentally enabled by a user / distro, it's only for development. Cc: <x86@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-05-15x86/asm/memcpy_mcsafe: Add write-protection-fault handlingDan Williams2-0/+35
In preparation for using memcpy_mcsafe() to handle user copies it needs to be to handle write-protection faults while writing user pages. Add MMU-fault handlers alongside the machine-check exception handlers. Note that the machine check fault exception handling makes assumptions about source buffer alignment and poison alignment. In the write fault case, given the destination buffer is arbitrarily aligned, it needs a separate / additional fault handling approach. The mcsafe_handle_tail() helper is reused. The @limit argument is set to @len since there is no safety concern about retriggering an MMU fault, and this simplifies the assembly. Co-developed-by: Tony Luck <tony.luck@intel.com> Reported-by: Mika Penttilä <mika.penttila@nextfour.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539238635.31796.14056325365122961778.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15x86/asm/memcpy_mcsafe: Return bytes remainingDan Williams1-6/+14
Machine check safe memory copies are currently deployed in the pmem driver whenever reading from persistent memory media, so that -EIO is returned rather than triggering a kernel panic. While this protects most pmem accesses, it is not complete in the filesystem-dax case. When filesystem-dax is enabled reads may bypass the block layer and the driver via dax_iomap_actor() and its usage of copy_to_iter(). In preparation for creating a copy_to_iter() variant that can handle machine checks, teach memcpy_mcsafe() to return the number of bytes remaining rather than -EFAULT when an exception occurs. Co-developed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539238119.31796.14318473522414462886.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handlingDan Williams1-9/+12
The memcpy_mcsafe() implementation handles CPU exceptions when reading from the source address. Before it can be used for user copies it needs to grow support for handling write faults. In preparation for adding that exception handling update the labels for the read cache word X case (.L_cache_rX) and write cache word X case (.L_cache_wX). Reported-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539237606.31796.6719743548991782264.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-15x86/asm/memcpy_mcsafe: Remove loop unrollingDan Williams1-49/+10
In preparation for teaching memcpy_mcsafe() to return 'bytes remaining' rather than pass / fail, simplify the implementation to remove loop unrolling. The unrolling complicates the fault handling for negligible benefit given modern CPUs perform loop stream detection. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: hch@lst.de Cc: linux-fsdevel@vger.kernel.org Cc: linux-nvdimm@lists.01.org Link: http://lkml.kernel.org/r/152539237092.31796.9115692316555638048.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-14x86/asm/64: Micro-optimize __clear_user() - Use immediate constantsAlexey Dobriyan1-5/+4
Save two registers. Adding constants should be just as fast as adding registers. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180507213937.GB32406@avx2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-03Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-15/+28
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups and msr updates from Ingo Molnar: "The main change is a performance/latency improvement to /dev/msr access. The rest are misc cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/msr: Make rdmsrl_safe_on_cpu() scheduling safe as well x86/cpuid: Allow cpuid_read() to schedule x86/msr: Allow rdmsr_safe_on_cpu() to schedule x86/rtc: Stop using deprecated functions x86/dumpstack: Unify show_regs() x86/fault: Do not print IP in show_fault_oops() x86/MSR: Move native_* variants to msr.h
2018-04-03Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm fixlets from Ingo Molnar: "A clobber list fix and cleanups" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm: Trim clear_page.S includes x86/asm: Clobber flags in clear_page()
2018-03-28x86/msr: Make rdmsrl_safe_on_cpu() scheduling safe as wellEric Dumazet1-7/+4
When changing rdmsr_safe_on_cpu() to schedule, it was missed that __rdmsr_safe_on_cpu() was also used by rdmsrl_safe_on_cpu() Make rdmsrl_safe_on_cpu() a wrapper instead of copy/pasting the code which was added for the completion handling. Fixes: 07cde313b2d2 ("x86/msr: Allow rdmsr_safe_on_cpu() to schedule") Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: https://lkml.kernel.org/r/20180328032233.153055-1-edumazet@google.com
2018-03-27x86/msr: Allow rdmsr_safe_on_cpu() to scheduleEric Dumazet1-8/+24
High latencies can be observed caused by a daemon periodically reading various MSR on all cpus. On KASAN enabled kernels ~10ms latencies can be observed simply reading one MSR. Even without KASAN, sending an IPI to a CPU, which is in a deep sleep state or in a long hard IRQ disabled section, waiting for the answer can consume hundreds of microseconds. All usage sites are in preemptible context, convert rdmsr_safe_on_cpu() to use a completion instead of busy polling. Overall daemon cpu usage was reduced by 35 %, and latencies caused by msr_read() disappeared. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Eric Dumazet <eric.dumazet@gmail.com> Link: https://lkml.kernel.org/r/20180323215818.127774-1-edumazet@google.com
2018-02-26Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2-57/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Yet another pile of melted spectrum related changes: - sanitize the array_index_nospec protection mechanism: Remove the overengineered array_index_nospec_mask_check() magic and allow const-qualified types as index to avoid temporary storage in a non-const local variable. - make the microcode loader more robust by properly propagating error codes. Provide information about new feature bits after micro code was updated so administrators can act upon. - optimizations of the entry ASM code which reduce code footprint and make the code simpler and faster. - fix the {pmd,pud}_{set,clear}_flags() implementations to work properly on paravirt kernels by removing the address translation operations. - revert the harmful vmexit_fill_RSB() optimization - use IBRS around firmware calls - teach objtool about retpolines and add annotations for indirect jumps and calls. - explicitly disable jumplabel patching in __init code and handle patching failures properly instead of silently ignoring them. - remove indirect paravirt calls for writing the speculation control MSR as these calls are obviously proving the same attack vector which is tried to be mitigated. - a few small fixes which address build issues with recent compiler and assembler versions" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits) KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely() KVM/x86: Remove indirect MSR op calls from SPEC_CTRL objtool, retpolines: Integrate objtool with retpoline support more closely x86/entry/64: Simplify ENCODE_FRAME_POINTER extable: Make init_kernel_text() global jump_label: Warn on failed jump_label patching attempt jump_label: Explicitly disable jump labels in __init code x86/entry/64: Open-code switch_to_thread_stack() x86/entry/64: Move ASM_CLAC to interrupt_entry() x86/entry/64: Remove 'interrupt' macro x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry() x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP objtool: Add module specific retpoline rules objtool: Add retpoline validation objtool: Use existing global variables for options x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute() x86/boot, objtool: Annotate indirect jump in secondary_startup_64() x86/paravirt, objtool: Annotate indirect calls ...
2018-02-20Revert "x86/retpoline: Simplify vmexit_fill_RSB()"David Woodhouse2-57/+0
This reverts commit 1dde7415e99933bb7293d6b2843752cbdb43ec11. By putting the RSB filling out of line and calling it, we waste one RSB slot for returning from the function itself, which means one fewer actual function call we can make if we're doing the Skylake abomination of call-depth counting. It also changed the number of RSB stuffings we do on vmexit from 32, which was correct, to 16. Let's just stop with the bikeshedding; it didn't actually *fix* anything anyway. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: arjan.van.de.ven@intel.com Cc: bp@alien8.de Cc: dave.hansen@intel.com Cc: jmattson@google.com Cc: karahmed@amazon.de Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Cc: rkrcmar@redhat.com Link: http://lkml.kernel.org/r/1519037457-7643-4-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-15Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes all across the map: - /proc/kcore vsyscall related fixes - LTO fix - build warning fix - CPU hotplug fix - Kconfig NR_CPUS cleanups - cpu_has() cleanups/robustification - .gitignore fix - memory-failure unmapping fix - UV platform fix" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm, mm/hwpoison: Don't unconditionally unmap kernel 1:1 pages x86/error_inject: Make just_return_func() globally visible x86/platform/UV: Fix GAM Range Table entries less than 1GB x86/build: Add arch/x86/tools/insn_decoder_test to .gitignore x86/smpboot: Fix uncore_pci_remove() indexing bug when hot-removing a physical CPU x86/mm/kcore: Add vsyscall page to /proc/kcore conditionally vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page x86/Kconfig: Further simplify the NR_CPUS config x86/Kconfig: Simplify NR_CPUS config x86/MCE: Fix build warning introduced by "x86: do not use print_symbol()" x86/cpufeature: Update _static_cpu_has() to use all named variables x86/cpufeature: Reindent _static_cpu_has()
2018-02-15Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar: "Here's the latest set of Spectre and PTI related fixes and updates: Spectre: - Add entry code register clearing to reduce the Spectre attack surface - Update the Spectre microcode blacklist - Inline the KVM Spectre helpers to get close to v4.14 performance again. - Fix indirect_branch_prediction_barrier() - Fix/improve Spectre related kernel messages - Fix array_index_nospec_mask() asm constraint - KVM: fix two MSR handling bugs PTI: - Fix a paranoid entry PTI CR3 handling bug - Fix comments objtool: - Fix paranoid_entry() frame pointer warning - Annotate WARN()-related UD2 as reachable - Various fixes - Add Add Peter Zijlstra as objtool co-maintainer Misc: - Various x86 entry code self-test fixes - Improve/simplify entry code stack frame generation and handling after recent heavy-handed PTI and Spectre changes. (There's two more WIP improvements expected here.) - Type fix for cache entries There's also some low risk non-fix changes I've included in this branch to reduce backporting conflicts: - rename a confusing x86_cpu field name - de-obfuscate the naming of single-TLB flushing primitives" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) x86/entry/64: Fix CR3 restore in paranoid_exit() x86/cpu: Change type of x86_cache_size variable to unsigned int x86/spectre: Fix an error message x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping selftests/x86/mpx: Fix incorrect bounds with old _sigfault x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]() x86/speculation: Add <asm/msr-index.h> dependency nospec: Move array_index_nospec() parameter checking into separate macro x86/speculation: Fix up array_index_nospec_mask() asm constraint x86/debug: Use UD2 for WARN() x86/debug, objtool: Annotate WARN()-related UD2 as reachable objtool: Fix segfault in ignore_unreachable_insn() selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory selftests/x86/pkeys: Remove unused functions selftests/x86: Clean up and document sscanf() usage selftests/x86: Fix vDSO selftest segfault for vsyscall=none x86/entry/64: Remove the unused 'icebp' macro ...
2018-02-15x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_steppingJia Zhang1-1/+1
x86_mask is a confusing name which is hard to associate with the processor's stepping. Additionally, correct an indent issue in lib/cpu.c. Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com> [ Updated it to more recent kernels. ] Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: tony.luck@intel.com Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-13x86/asm: Trim clear_page.S includesAlexey Dobriyan1-2/+0
After alternatives were shifted to the call site, only 2 headers are necessary. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180113190648.GB23111@avx2 Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-13x86/error_inject: Make just_return_func() globally visibleArnd Bergmann1-0/+1
With link time optimizations enabled, I get a link failure: ./ccLbOEHX.ltrans19.ltrans.o: In function `override_function_with_return': <artificial>:(.text+0x7f3): undefined reference to `just_return_func' Marking the symbol .globl makes it work as expected. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Josef Bacik <jbacik@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Fixes: 540adea3809f ("error-injection: Separate error-injection from kprobe") Link: http://lkml.kernel.org/r/20180202145634.200291-3-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-04Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2-4/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull spectre/meltdown updates from Thomas Gleixner: "The next round of updates related to melted spectrum: - The initial set of spectre V1 mitigations: - Array index speculation blocker and its usage for syscall, fdtable and the n180211 driver. - Speculation barrier and its usage in user access functions - Make indirect calls in KVM speculation safe - Blacklisting of known to be broken microcodes so IPBP/IBSR are not touched. - The initial IBPB support and its usage in context switch - The exposure of the new speculation MSRs to KVM guests. - A fix for a regression in x86/32 related to the cpu entry area - Proper whitelisting for known to be safe CPUs from the mitigations. - objtool fixes to deal proper with retpolines and alternatives - Exclude __init functions from retpolines which speeds up the boot process. - Removal of the syscall64 fast path and related cleanups and simplifications - Removal of the unpatched paravirt mode which is yet another source of indirect unproteced calls. - A new and undisputed version of the module mismatch warning - A couple of cleanup and correctness fixes all over the place Yet another step towards full mitigation. There are a few things still missing like the RBS underflow mitigation for Skylake and other small details, but that's being worked on. That said, I'm taking a belated christmas vacation for a week and hope that everything is magically solved when I'm back on Feb 12th" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/x86: Add IBPB support KVM/x86: Update the reverse_cpuid list to include CPUID_7_EDX x86/speculation: Fix typo IBRS_ATT, which should be IBRS_ALL x86/pti: Mark constant arrays as __initconst x86/spectre: Simplify spectre_v2 command line parsing x86/retpoline: Avoid retpolines for built-in __init functions x86/kvm: Update spectre-v1 mitigation KVM: VMX: make MSR bitmaps per-VCPU x86/paravirt: Remove 'noreplace-paravirt' cmdline option x86/speculation: Use Indirect Branch Prediction Barrier in context switch x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel x86/spectre: Fix spelling mistake: "vunerable"-> "vulnerable" x86/spectre: Report get_user mitigation for spectre_v1 nl80211: Sanitize array index in parse_txq_params vfs, fdtable: Prevent bounds-check bypass via speculative execution x86/syscall: Sanitize syscall table de-references under speculation x86/get_user: Use pointer masking to limit speculation ...
2018-02-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2-0/+20
Pull networking updates from David Miller: 1) Significantly shrink the core networking routing structures. Result of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf 2) Add netdevsim driver for testing various offloads, from Jakub Kicinski. 3) Support cross-chip FDB operations in DSA, from Vivien Didelot. 4) Add a 2nd listener hash table for TCP, similar to what was done for UDP. From Martin KaFai Lau. 5) Add eBPF based queue selection to tun, from Jason Wang. 6) Lockless qdisc support, from John Fastabend. 7) SCTP stream interleave support, from Xin Long. 8) Smoother TCP receive autotuning, from Eric Dumazet. 9) Lots of erspan tunneling enhancements, from William Tu. 10) Add true function call support to BPF, from Alexei Starovoitov. 11) Add explicit support for GRO HW offloading, from Michael Chan. 12) Support extack generation in more netlink subsystems. From Alexander Aring, Quentin Monnet, and Jakub Kicinski. 13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From Russell King. 14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso. 15) Many improvements and simplifications to the NFP driver bpf JIT, from Jakub Kicinski. 16) Support for ipv6 non-equal cost multipath routing, from Ido Schimmel. 17) Add resource abstration to devlink, from Arkadi Sharshevsky. 18) Packet scheduler classifier shared filter block support, from Jiri Pirko. 19) Avoid locking in act_csum, from Davide Caratti. 20) devinet_ioctl() simplifications from Al viro. 21) More TCP bpf improvements from Lawrence Brakmo. 22) Add support for onlink ipv6 route flag, similar to ipv4, from David Ahern. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits) tls: Add support for encryption using async offload accelerator ip6mr: fix stale iterator net/sched: kconfig: Remove blank help texts openvswitch: meter: Use 64-bit arithmetic instead of 32-bit tcp_nv: fix potential integer overflow in tcpnv_acked r8169: fix RTL8168EP take too long to complete driver initialization. qmi_wwan: Add support for Quectel EP06 rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK ipmr: Fix ptrdiff_t print formatting ibmvnic: Wait for device response when changing MAC qlcnic: fix deadlock bug tcp: release sk_frag.page in tcp_disconnect ipv4: Get the address of interface correctly. net_sched: gen_estimator: fix lockdep splat net: macb: Handle HRESP error net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring ipv6: addrconf: break critical section in addrconf_verify_rtnl() ipv6: change route cache aging logic i40e/i40evf: Update DESC_NEEDED value to reflect larger value bnxt_en: cleanup DIM work on device shutdown ...
2018-01-31Merge branch 'x86-cleanups-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Misc cleanups" * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Remove unused IOMMU_STRESS Kconfig x86/extable: Mark exception handler functions visible x86/timer: Don't inline __const_udelay x86/headers: Remove duplicate #includes
2018-01-30x86/get_user: Use pointer masking to limit speculationDan Williams1-0/+10
Quoting Linus: I do think that it would be a good idea to very expressly document the fact that it's not that the user access itself is unsafe. I do agree that things like "get_user()" want to be protected, but not because of any direct bugs or problems with get_user() and friends, but simply because get_user() is an excellent source of a pointer that is obviously controlled from a potentially attacking user space. So it's a prime candidate for then finding _subsequent_ accesses that can then be used to perturb the cache. Unlike the __get_user() case get_user() includes the address limit check near the pointer de-reference. With that locality the speculation can be mitigated with pointer narrowing rather than a barrier, i.e. array_index_nospec(). Where the narrowing is performed by: cmp %limit, %ptr sbb %mask, %mask and %mask, %ptr With respect to speculation the value of %ptr is either less than %limit or NULL. Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727417469.33451.11804043010080838495.stgit@dwillia2-desk3.amr.corp.intel.com
2018-01-30x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospecDan Williams1-2/+2
Quoting Linus: I do think that it would be a good idea to very expressly document the fact that it's not that the user access itself is unsafe. I do agree that things like "get_user()" want to be protected, but not because of any direct bugs or problems with get_user() and friends, but simply because get_user() is an excellent source of a pointer that is obviously controlled from a potentially attacking user space. So it's a prime candidate for then finding _subsequent_ accesses that can then be used to perturb the cache. __uaccess_begin_nospec() covers __get_user() and copy_from_iter() where the limit check is far away from the user pointer de-reference. In those cases a barrier_nospec() prevents speculation with a potential pointer to privileged memory. uaccess_try_nospec covers get_user_try. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727416953.33451.10508284228526170604.stgit@dwillia2-desk3.amr.corp.intel.com
2018-01-30x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end}Dan Williams1-4/+4
In preparation for converting some __uaccess_begin() instances to __uacess_begin_nospec(), make sure all 'from user' uaccess paths are using the _begin(), _end() helpers rather than open-coded stac() and clac(). No functional changes. Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@chromium.org> Cc: kernel-hardening@lists.openwall.com Cc: gregkh@linuxfoundation.org Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: torvalds@linux-foundation.org Cc: alan@linux.intel.com Link: https://lkml.kernel.org/r/151727416438.33451.17309465232057176966.stgit@dwillia2-desk3.amr.corp.intel.com
2018-01-30Merge tag 'v4.15' into x86/pti, to be able to merge dependent changesIngo Molnar4-4/+1389
Time has come to switch PTI development over to a v4.15 base - we'll still try to make sure that all PTI fixes backport cleanly to v4.14 and earlier. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-30Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds2-0/+57
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/pti updates from Thomas Gleixner: "Another set of melted spectrum related changes: - Code simplifications and cleanups for RSB and retpolines. - Make the indirect calls in KVM speculation safe. - Whitelist CPUs which are known not to speculate from Meltdown and prepare for the new CPUID flag which tells the kernel that a CPU is not affected. - A less rigorous variant of the module retpoline check which merily warns when a non-retpoline protected module is loaded and reflects that fact in the sysfs file. - Prepare for Indirect Branch Prediction Barrier support. - Prepare for exposure of the Speculation Control MSRs to guests, so guest OSes which depend on those "features" can use them. Includes a blacklist of the broken microcodes. The actual exposure of the MSRs through KVM is still being worked on" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/speculation: Simplify indirect_branch_prediction_barrier() x86/retpoline: Simplify vmexit_fill_RSB() x86/cpufeatures: Clean up Spectre v2 related CPUID flags x86/cpu/bugs: Make retpoline module warning conditional x86/bugs: Drop one "mitigation" from dmesg x86/nospec: Fix header guards names x86/alternative: Print unadorned pointers x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown x86/msr: Add definitions for new speculation control MSRs x86/cpufeatures: Add AMD feature bits for Speculation Control x86/cpufeatures: Add Intel feature bits for Speculation Control x86/cpufeatures: Add CPUID_7_EDX CPUID leaf module/retpoline: Warn about missing retpoline in module KVM: VMX: Make indirect call speculation safe KVM: x86: Make indirect calls in emulator speculation safe
2018-01-28Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 retpoline fixlet from Thomas Gleixner: "Remove the ESP/RSP thunks for retpoline as they cannot ever work. Get rid of them before they show up in a release" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/retpoline: Remove the esp/rsp thunk
2018-01-27x86/retpoline: Simplify vmexit_fill_RSB()Borislav Petkov2-0/+57
Simplify it to call an asm-function instead of pasting 41 insn bytes at every call site. Also, add alignment to the macro as suggested here: https://support.google.com/faqs/answer/7625886 [dwmw2: Clean up comments, let it clobber %ebx and just tell the compiler] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ak@linux.intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517070274-12128-3-git-send-email-dwmw@amazon.co.uk
2018-01-24x86/retpoline: Remove the esp/rsp thunkWaiman Long1-1/+0
It doesn't make sense to have an indirect call thunk with esp/rsp as retpoline code won't work correctly with the stack pointer register. Removing it will help compiler writers to catch error in case such a thunk call is emitted incorrectly. Fixes: 76b043848fd2 ("x86/retpoline: Add initial retpoline support") Suggested-by: Jeff Law <law@redhat.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Kees Cook <keescook@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1516658974-27852-1-git-send-email-longman@redhat.com
2018-01-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+3
en_rx_am.c was deleted in 'net-next' but had a bug fixed in it in 'net'. The esp{4,6}_offload.c conflicts were overlapping changes. The 'out' label is removed so we just return ERR_PTR(-EINVAL) directly. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-21Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 pti fixes from Thomas Gleixner: "A small set of fixes for the meltdown/spectre mitigations: - Make kprobes aware of retpolines to prevent probes in the retpoline thunks. - Make the machine check exception speculation protected. MCE used to issue an indirect call directly from the ASM entry code. Convert that to a direct call into a C-function and issue the indirect call from there so the compiler can add the retpoline protection, - Make the vmexit_fill_RSB() assembly less stupid - Fix a typo in the PTI documentation" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/retpoline: Optimize inline assembler for vmexit_fill_RSB x86/pti: Document fix wrong index kprobes/x86: Disable optimizing on the function jumps to indirect thunk kprobes/x86: Blacklist indirect thunk functions for kprobes retpoline: Introduce start/end markers of indirect thunk x86/mce: Make machine check speculation protected
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