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* exit/xtensa: In arch/xtensa/entry.S:Linvalid_mask call make_task_deadEric W. Biederman2022-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | There have historically been two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. The function make_task_dead has been added to accomidate the second use. The call to do_exit in Linvalidmask is clearly not a normal userspace exit. As failure handling there are two possible ways to go. If userspace can trigger the issue force_exit_sig should be called. Otherwise make_task_dead probably from the implementation of die is appropriate. Replace the call of do_exit in Linvalidmask with make_task_dead as I don't know xtensa and especially xtensa assembly language well enough to do anything else. Link: https://lkml.kernel.org/r/YdUmN7n4W5YETUhW@zeniv-ca.linux.org.uk Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* xtensa: only build windowed register support code when neededMax Filippov2021-10-181-1/+4
| | | | | | | | There's no need in window overflow/underflow/alloca exception handlers or window spill code when neither kernel nor userspace support windowed registers. Don't build or link it. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: use register window specific opcodes only when presentMax Filippov2021-10-181-0/+2
| | | | | | | | | xtensa core may be configured without register windows support, don't use register window specific opcodes in that case. Use window register specific opcodes to initialize hardware or reset core to a known state regardless of the chosen ABI. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: implement call0 ABI support in assemblyMax Filippov2021-10-181-74/+135
| | | | | | | | | Replace hardcoded register and opcode names with ABI-agnostic macros. Add register save/restore code where necessary. Conditionalize windowed only or call0 only code. Add stack initialization matching _switch_to epilogue to copy_thread. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: add support for TIF_NOTIFY_SIGNALJens Axboe2020-11-121-2/+2
| | | | | | | | | Wire up TIF_NOTIFY_SIGNAL handling for xtensa. Thanks to Max Filippov <jcmvbkbc@gmail.com> for making the asm correct. Cc: linux-xtensa@linux-xtensa.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* xtensa: add missing exclusive access state managementMax Filippov2020-07-311-0/+11
| | | | | | | | | | | | | | The result of the s32ex opcode is recorded in the ATOMCTL special register and must be retrieved with the getex opcode. Context switch between s32ex and getex may trash the ATOMCTL register and result in duplicate update or missing update of the atomic variable. Add atomctl8 field to the struct thread_info and use getex to swap ATOMCTL bit 8 as a part of context switch. Clear exclusive access monitor on kernel entry. Cc: stable@vger.kernel.org Fixes: f7c34874f04a ("xtensa: add exclusive atomics support") Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* mm: reorder includes after introduction of linux/pgtable.hMike Rapoport2020-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s <file> <header>" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include <linux/%s>" % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include <linux/"): in_hdrs = True elif not moved and in_hdrs: moved = True print hdr_to_move print line Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce include/linux/pgtable.hMike Rapoport2020-06-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xtensa: Fix spelling/grammar in commentChris Packham2020-05-251-2/+2
| | | | | | | | | Change 'excpetion' to 'exception', 'handeled' to 'handled' and 'the the' to 'the'. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Message-Id: <20200525230413.15551-1-chris.packham@alliedtelesis.co.nz> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* Merge tag 'xtensa-20200206' of git://github.com/jcmvbkbc/linux-xtensaLinus Torvalds2020-02-071-6/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull xtensa updates from Max Filippov: - reorganize exception vectors placement - small cleanups (drop unused functions/headers/defconfig entries, spelling fixes) * tag 'xtensa-20200206' of git://github.com/jcmvbkbc/linux-xtensa: xtensa: ISS: improve simcall assembly xtensa: reorganize vectors placement xtensa: separate SMP and XIP support xtensa: move fast exception handlers close to vectors arch/xtensa: fix Kconfig typos for HAVE_SMP xtensa: clean up optional XCHAL_* definitions xtensa: drop unused function fast_coprocessor_double xtensa: drop empty platform_* functions from platforms xtensa: clean up platform headers xtensa: drop set_except_vector declaration xtensa: configs: Cleanup old Kconfig IO scheduler options
| * xtensa: move fast exception handlers close to vectorsMax Filippov2020-02-041-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | On XIP kernels it makes sense to have exception vectors and fast exception handlers together (in a fast memory). In addition, with MTD XIP support both vectors and fast exception handlers must be outside of the FLASH. Add section .exception.text and move fast exception handlers to it. Put it together with vectors when vectors are outside of the .text. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* | sched/rt, xtensa: Use CONFIG_PREEMPTIONThomas Gleixner2019-12-081-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Switch the entry code over to use CONFIG_PREEMPTION. Add PREEMPT_RT output to die(). [bigeasy: +traps.c] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Cc: Chris Zankel <chris@zankel.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-xtensa@linux-xtensa.org Link: https://lore.kernel.org/r/20191015191821.11479-21-bigeasy@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* xtensa: clean up system_call/xtensa_rt_sigreturn interactionMax Filippov2019-11-291-7/+3
| | | | | | | | | | | | system_call assembly code always pushes pointer to struct pt_regs as the last additional parameter for all system calls. The only user of this feature is xtensa_rt_sigreturn. Avoid this special case. Define xtensa_rt_sigreturn as accepting no argiments. Use current_pt_regs to get pointer to struct pt_regs in xtensa_rt_sigreturn. Don't pass additional parameter from system_call code. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix system_call interaction with ptraceMax Filippov2019-11-291-2/+2
| | | | | | | | Don't overwrite return value if system call was cancelled at entry by ptrace. Return status code from do_syscall_trace_enter so that pt_regs::syscall doesn't need to be changed to skip syscall. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: rearrange syscall tracingMax Filippov2019-11-291-6/+0
| | | | | | | | | | system_call saves and restores syscall number across system call to make clone and execv entry and exit tracing match. This complicates things when syscall code may be changed by ptrace. Preserve syscall code in copy_thread and start_thread directly instead of doing tricks in system_call. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: entry: Remove unneeded need_resched() loopValentin Schneider2019-11-261-1/+1
| | | | | | | | | | | Since the enabling and disabling of IRQs within preempt_schedule_irq() is contained in a need_resched() loop, we don't need the outer arch code loop. Acked-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Message-Id: <20190923143620.29334-10-valentin.schneider@arm.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: add support for call0 ABI in userspaceMax Filippov2019-09-011-0/+34
| | | | | | | | | | | | | | Provide a Kconfig choice to select whether only the default ABI, only call0 ABI or both are supported. The default for XEA2 is windowed, but it may change for XEA3. Call0 only runs userspace with PS.WOE disabled. Supporting both windowed and call0 ABIs is tricky, as there's no indication in the ELF binaries which ABI they use. So it is done by probing: each process is started with PS.WOE disabled, but the handler of an illegal instruction exception taken with PS.WOE retries faulting instruction after enabling PS.WOE. It must happen before any signal is delivered to the process, otherwise it may be delivered incorrectly. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: clean up PS_WOE_BIT usageMax Filippov2019-09-011-4/+4
| | | | | | | PS_WOE_BIT is mainly used to generate PS.WOE mask in the code. Introduce PS_WOE_MASK macro and use it instead. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: abstract 'entry' and 'retw' in assembly codeMax Filippov2019-07-081-5/+6
| | | | | | | | | | | Provide abi_entry, abi_entry_default, abi_ret and abi_ret_default macros that allocate aligned stack frame in windowed and call0 ABIs. Provide XTENSA_SPILL_STACK_RESERVE macro that specifies required stack frame size when register spilling is involved. Replace all uses of 'entry' and 'retw' with the above macros. This makes most of the xtensa assembly code ready for XEA3 and call0 ABI. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: use actual syscall number in do_syscall_trace_leaveMax Filippov2019-04-031-0/+6
| | | | | | | | | Syscall may alter pt_regs structure passed to it, resulting in a mismatch between syscall entry end syscall exit entries in the ftrace. Temporary restore syscall field of the pt_regs for the duration of do_syscall_trace_leave. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: call do_syscall_trace_{enter,leave} selectivelyMax Filippov2018-12-171-5/+17
| | | | | | | | Check whether calls to do_syscall_trace_{enter,leave} are necessary in the system_call function. Define _TIF_WORK_MASK to a bitmask of flags that reuire the calls. Fix comment. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: use NO_SYSCALL instead of -1Max Filippov2018-12-171-1/+1
| | | | | | | For the sake of clarity define macro NO_SYSCALL and use it for setting/checking struct pt_regs::syscall field. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: drop fast_syscall_kernelMax Filippov2018-12-031-19/+0
| | | | | | | | There must be no xtensa-specific syscalls from the kernel code: register spilling uses call+entry sequence and atomics have proper function implementations. Drop fast_syscall_xtensa. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: add __NR_syscalls along with __NR_syscall_countFiroz Khan2018-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __NR_syscall_count macro holds the number of system call exist in xtensa architecture. We have to change the value of __NR_syscall_count, if we add or delete a system call. One of the patch in this patch series has a script which will generate a uapi header based on syscall.tbl file. The syscall.tbl file contains the total number of system calls information. So we have two option to update __NR- _syscall_count value. 1. Update __NR_syscall_count in asm/unistd.h manually by counting the no.of system calls. No need to update __NR- _syscall_count until we either add a new system call or delete existing system call. 2. We can keep this feature it above mentioned script, that will count the number of syscalls and keep it in a generated file. In this case we don't need to expli- citly update __NR_syscall_count in asm/unistd.h file. The 2nd option will be the recommended one. For that, I added the __NR_syscalls macro in uapi/asm/unistd.h. The macro __NR_syscalls also added for making the name convention same across all architecture. While __NR_syscalls isn't strictly part of the uapi, having it as part of the generated header to simplifies the implementation. We also need to enclose this macro with #ifdef __KERNEL__ to avoid side effects. Signed-off-by: Firoz Khan <firoz.khan@linaro.org> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> [Max: Drop __NR_syscall_count completely, use __NR_syscalls instead]
* Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variablesLinus Torvalds2018-06-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xtensa: enable stack protectorMax Filippov2017-12-161-0/+6
| | | | | | | The implementation is adopted from the ARM arch. GCC 7.3, 8 or newer is required for building the xtensa kernel with SSP. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: clean up fixups in assembly codeMax Filippov2017-12-101-28/+5
| | | | | | | Remove duplicate definitions of EX() and similar TRY/CATCH and SRC/DST macros from assembly sources and put single definition into asm/asmmacro.h Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: use call instead of callx in assembly codeMax Filippov2017-12-101-37/+19
| | | | | | | | Now that xtensa assembly sources are compiled with -mlongcalls let the assembler and linker relax call instructions into l32r + callx where needed. This change makes the code cleaner and potentially a bit faster. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: build kernel with text-section-literalsMax Filippov2017-12-101-0/+8
| | | | | | | | | | | | vmlinux.lds.S doesn't do anything special with literals, so instead of keeping them separate put them into the corresponding text sections. Drop explicit .literal sections from the vmlinux.lds.S, use standard section macros. Mark literal pool locations in the assembly sources. Unfortunately assembler doesn't put literals into .init sections and external libgcc may still have .literal sections, so sed transformation to the linker script is still needed. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: use generic tracehooksMax Filippov2017-05-011-1/+2
| | | | | | | | Use tracehook_report_syscall_{entry,exit} instead of a local copy of it in do_syscall_trace. Allow tracehook to cancel syscall by returning invalid syscall number to the system_call function. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* Merge branch 'work.uaccess2' of ↵Linus Torvalds2016-10-111-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uaccess.h prepwork from Al Viro: "Preparations to tree-wide switch to use of linux/uaccess.h (which, obviously, will allow to start unifying stuff for real). The last step there, ie PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ `git grep -l "$PATT"|grep -v ^include/linux/uaccess.h` is not taken here - I would prefer to do it once just before or just after -rc1. However, everything should be ready for it" * 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: remove a stray reference to asm/uaccess.h in docs sparc64: separate extable_64.h, switch elf_64.h to it score: separate extable.h, switch module.h to it mips: separate extable.h, switch module.h to it x86: separate extable.h, switch sections.h to it remove stray include of asm/uaccess.h from cacheflush.h mn10300: remove a bogus processor.h->uaccess.h include xtensa: split uaccess.h into C and asm sides bonding: quit messing with IOCTL kill __kernel_ds_p off mn10300: finish verify_area() off frv: move HAVE_ARCH_UNMAPPED_AREA to pgtable.h exceptions: detritus removal
| * xtensa: split uaccess.h into C and asm sidesAl Viro2016-09-271-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | xtensa: cleanup MMU setup and kernel layout macrosMax Filippov2016-07-241-2/+3
|/ | | | | | | | | | | | | | | | Make kernel load address explicit, independent of the selected MMU configuration and configurable from Kconfig. Do not restrict it to the first 512MB of the physical address space. Cleanup kernel memory layout macros: - rename VECBASE_RESET_VADDR to VECBASE_VADDR, XC_VADDR to VECTOR_VADDR; - drop VIRTUAL_MEMORY_ADDRESS and LOAD_MEMORY_ADDRESS; - introduce PHYS_OFFSET and use it in __va and __pa definitions; - synchronize MMU/noMMU vectors, drop unused NMI vector; - replace hardcoded vectors offset of 0x3000 with Kconfig symbol. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: support hardware breakpoints/watchpointsMax Filippov2016-03-111-1/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | Use perf framework to manage hardware instruction and data breakpoints. Add two new ptrace calls: PTRACE_GETHBPREGS and PTRACE_SETHBPREGS to query and set instruction and data breakpoints. Address bit 0 choose instruction (0) or data (1) break register, bits 31..1 are the register number. Both calls transfer two 32-bit words: address (0) and control (1). Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set. Data breakpoint control word bit 31 is 'trigger on store', bit 30 is 'trigger on load, bits 29..0 are length. Length 0 is used to clear a breakpoint. To set a breakpoint length must be a power of 2 in the range 1..64 and the address must be length-aligned. Introduce new thread_info flag: TIF_DB_DISABLED. Set it if debug exception is raised by the kernel code accessing watched userspace address and disable corresponding data breakpoint. On exit to userspace check that flag and, if set, restore all data breakpoints. Handle debug exceptions raised with PS.EXCM set. This may happen when window overflow/underflow handler or fast exception handler hits data breakpoint, in which case save and disable all data breakpoints, single-step faulting instruction and restore data breakpoints. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: use context structure for debug exceptionsMax Filippov2016-03-111-12/+8
| | | | | | | | | | | | | | | With implementation of data breakpoints debug exceptions raised when PS.EXCM is set need to be handled, e.g. window overflow code can write to watched userspace address. Currently debug exception handler uses EXCSAVE and DEPC SRs to save temporary registers, but DEPC may not be available when PS.EXCM is set and more space will be needed to save additional state. Reorganize debug context: create per-CPU structure debug_table instance and store its address in the EXCSAVE<debug level> instead of debug_exception function address. Expand this structure when more save space is needed. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fixes for configs without loop optionMax Filippov2015-11-021-2/+6
| | | | | | | | | | | | | | | | Build-time fixes: - make lbeg/lend/lcount save/restore conditional on kernel entry; - don't clear lcount in platform_restart functions unconditionally. Run-time fixes: - use correct end of range register in __endla paired with __loopt, not the unused temporary register. This fixes .bss zero-initialization. Update comments in asmmacro.h; - don't clobber a10 in the usercopy that leads to access to unmapped memory. Cc: <stable@vger.kernel.org> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: implement fake NMIMax Filippov2015-08-171-14/+79
| | | | | | | | | | | | | | | | In case perf IRQ is the highest of the medium-level IRQs, and is alone on its level, it may be treated as NMI: - LOCKLEVEL is defined to be one level less than EXCM level, - IRQ masking never lowers current IRQ level, - new fake exception cause code, EXCCAUSE_MAPPED_NMI is assigned to that IRQ; new second level exception handler, do_nmi, assigned to it handles it as NMI, - atomic operations in configurations without s32c1i still need to mask all interrupts. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: don't touch EXC_TABLE_FIXUP in _switch_toMax Filippov2015-08-171-4/+0
| | | | | | | There's no way _switch_to can produce double exceptions now, don't enter/leave EXC_TABLE_FIXUP critical section. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix kernel register spillingMax Filippov2015-08-171-2/+2
| | | | | | | | | | | | | | call12 can't be safely used as the first call in the inline function, because the compiler does not extend the stack frame of the bounding function accordingly, which may result in corruption of local variables. If a call needs to be done, do call8 first followed by call12. For pure assembly code in _switch_to increase stack frame size of the bounding function. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: reorganize irq flags tracingMax Filippov2015-08-171-25/+14
| | | | | | | | | | entry.s only disables IRQs on hardware IRQ, move trace_hardirqs_off call into do_interrupt. Check actual intlevel that will be restored on return from exception handler to decide if trace_hardirqs_on should be called. Annotate IRQ on/off points in the TIF_* handling loop on return from exception handler. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: keep exception/interrupt stack continuousMax Filippov2015-08-171-15/+28
| | | | | | | | | | | | Restore original a0 in the kernel exception stack frame. This way it looks like the frame that got interrupt/exception did alloca (copy a0 and a1 spilled under old stack to the new location as well) to save registers and then did a call to handler. The point where interrupt/exception was taken is not in the stack chain, only in pt_regs (call4 from that address can be simulated to keep it in the stack trace). Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix threadptr reload on return to userspaceMax Filippov2015-07-151-1/+2
| | | | | | | | | | | Userspace return code may skip restoring THREADPTR register if there are no registers that need to be zeroed. This leads to spurious failures in libc NPTL tests. Always restore THREADPTR on return to userspace. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: deprecate fast_xtensa and fast_spill_registers syscallsMax Filippov2014-08-141-0/+28
| | | | | | | | | | These syscalls are not used by userspace tools for some time now, and they have issues when called with invalid arguments. It's not worth changing signal delivery mechanism as we don't expect any new users for these syscalls. Let's keep them for backwards compatibility under #ifdef, disabled by default. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix a6 and a7 handling in fast_syscall_xtensaMax Filippov2014-08-141-7/+5
| | | | | | | | | Remove restoring a6 on some return paths and instead modify and restore it in a single place, using symbolic name. Correctly restore a7 from PT_AREG7 in case of illegal a6 value. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix TLBTEMP_BASE_2 region handling in fast_second_level_missMax Filippov2014-08-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | Current definition of TLBTEMP_BASE_2 is always 32K above the TLBTEMP_BASE_1, whereas fast_second_level_miss handler for the TLBTEMP region analyzes virtual address bit (PAGE_SHIFT + DCACHE_ALIAS_ORDER) to determine TLBTEMP region where the fault happened. The size of the TLBTEMP region is also checked incorrectly: not 64K, but twice data cache way size (whicht may as well be less than the instruction cache way size). Fix TLBTEMP_BASE_2 to be TLBTEMP_BASE_1 + data cache way size. Provide TLBTEMP_SIZE that is a greater of doubled data cache way size or the instruction cache way size, and use it to determine if the second level TLB miss occured in the TLBTEMP region. Practical occurence of page faults in the TLBTEMP area is extremely rare, this code can be tested by deletion of all w[di]tlb instructions in the tlbtemp_mapping region. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix access to THREAD_RA/THREAD_SP/THREAD_DSMax Filippov2014-08-141-4/+8
| | | | | | | | | | | | | | | | | | With SMP and a lot of debug options enabled task_struct::thread gets out of reach of s32i/l32i instructions with base pointing at task_struct, breaking build with the following messages: arch/xtensa/kernel/entry.S: Assembler messages: arch/xtensa/kernel/entry.S:1002: Error: operand 3 of 'l32i.n' has invalid value '1048' arch/xtensa/kernel/entry.S:1831: Error: operand 3 of 's32i.n' has invalid value '1040' arch/xtensa/kernel/entry.S:1832: Error: operand 3 of 's32i.n' has invalid value '1044' Change base to point to task_struct::thread in such cases. Don't use a10 in _switch_to to save/restore prev pointer as a2 is not clobbered. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix fast_syscall_spill_registersChris Zankel2014-01-281-209/+174
| | | | | | | | | | | | | | | The original implementation could clobber registers under certain conditions. The Xtensa processor architecture uses windowed registers and the original implementation was using a4 as a temporary register, which under certain conditions could be register a0 of the oldest window frame, and didn't always restore the content correctly. By moving the _spill_registers routine inside the fast system call, it frees up one more register (the return address is not required anymore) for the spill routine. Signed-off-by: Chris Zankel <chris@zankel.net>
* xtensa: save current register frame in fast_syscall_spill_registers_fixupMax Filippov2014-01-251-0/+12
| | | | | | | | | We need it saved because it contains a3 where we track which register windows we still need to spill, and fixup handler may call C exception handlers. Also fix comments. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: introduce spill_registers_kernel macroMax Filippov2014-01-251-12/+48
| | | | | | | | | | | Most in-kernel users want registers spilled on the kernel stack and don't require PS.EXCM to be set. That means that they don't need fixup routine and could reuse regular window overflow mechanism for that, which makes spill routine very simple. Cc: stable@vger.kernel.org Suggested-by: Chris Zankel <chris@zankel.net> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix fast_syscall_spill_registers_fixupMax Filippov2013-10-151-19/+30
| | | | | | | | | | | | | | | | | | fast_syscall_spill_registers_fixup was not correctly updated by the 'keep a3 and excsave1 on entry to exception handlers' patch: it doesn't preserve a3 that it gets on entry, breaking _spill_registers in case of page fault on stack during register spilling, leading to unhandled exception in kernel mode. Preserve a3 by saving it in the original _spill_registers stack frame's a3 during exception handling and restoring it afterwards. Also fix comments and function bounds annotations. Reported-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Chris Zankel <chris@zankel.net>
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