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2018-06-14Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variablesLinus Torvalds1-1/+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>
2017-08-29MIPS: Move r4k FP code from r4k_switch.S to r4k_fpu.SPaul Burton1-203/+0
Move _save_fp(), _restore_fp(), _save_msa(), _restore_msa(), _init_msa_upper() & _init_fpu() out of r4k_switch.S & into r4k_fpu.S. This allows us to clean up the way in which Octeon includes the default r4k implementations of these FP functions despite replacing resume(), and makes CONFIG_R4K_FPU more straightforwardly represent all configurations that have an R4K-style FPU, including Octeon. Besides cleaning up this will be useful for later patches which disable FP support. [ralf@linux-mips.org: Fixed build issues reported by Arnd Bergmann <arnd@arndb.de>] Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16237/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-04-12MIPS: Remove dead define of ST_OFFMatt Redfearn1-6/+0
Commit 1a3d59579b9f ("MIPS: Tidy up FPU context switching") removed the last usage of the macro ST_OFF. Remove the dead code. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: trivial@kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/15898/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-01-03MIPS: Export _save_fp & _save_msa alongside their definitionsPaul Burton1-0/+3
Now that EXPORT_SYMBOL can be used from assembly source, move the EXPORT_SYMBOL invocations for _save_fp & _save_msa to be alongside their definitions. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: Remove redundant asm/pgtable-bits.h inclusionsPaul Burton1-1/+0
asm/pgtable-bits.h is included in 2 assembly files and thus has to ifdef around C code, however nothing defined by the header is used in either of the assembly files that include it. Remove the redundant inclusions such that asm/pgtable-bits.h doesn't need to #ifdef around C code, for cleanliness and in preparation for later patches which will add more C. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Jonas Gorski <jogo@openwrt.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13114/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03MIPS: Tidy up FPU context switchingPaul Burton1-40/+1
Rather than saving the scalar FP or vector context in the assembly resume function, reuse the existing C code we have in fpu.h to do exactly that. This reduces duplication, results in a much easier to read resume function & should allow the compiler to optimise out more MSA code due to is_msa_enabled()/cpu_has_msa being known-zero at compile time for kernels without MSA support. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-kernel@vger.kernel.org Cc: James Hogan <james.hogan@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: Manuel Lauss <manuel.lauss@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/10830/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-08MIPS: Respect the ISA level in FCSR handlingMaciej W. Rozycki1-5/+2
Define the central place the default FCSR value is set from, initialised in `cpu_probe'. Determine the FCSR mask applied to values written to the register with CTC1 in the full emulation mode and via ptrace(2), according to the ISA level of processor hardware or the writability of bits 31:18 if actual FPU hardware is used. Software may rely on FCSR bits whose functions our emulator does not implement, so it should not allow them to be set or software may get confused. For ptrace(2) it's just sanity. [ralf@linux-mips.org: Fixed double inclusion of <asm/current.h>.] Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9711/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-17MIPS: kernel: r4k_switch: Add support for MIPS R6Leonid Yegoshin1-6/+8
Add the MIPS R6 related preprocessor definitions for save/restore FPU related functions. We also set the appropriate ISA level so the final return instruction "jr ra" will produce the correct opcode on R6. Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2014-11-07MIPS: Fix build with binutils 2.24.51+Manuel Lauss1-1/+14
Starting with version 2.24.51.20140728 MIPS binutils complain loudly about mixing soft-float and hard-float object files, leading to this build failure since GCC is invoked with "-msoft-float" on MIPS: {standard input}: Warning: .gnu_attribute 4,3 requires `softfloat' LD arch/mips/alchemy/common/built-in.o mipsel-softfloat-linux-gnu-ld: Warning: arch/mips/alchemy/common/built-in.o uses -msoft-float (set by arch/mips/alchemy/common/prom.o), arch/mips/alchemy/common/sleeper.o uses -mhard-float To fix this, we detect if GAS is new enough to support "-msoft-float" command option, and if it does, we can let GCC pass it to GAS; but then we also need to sprinkle the files which make use of floating point registers with the necessary ".set hardfloat" directives. Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com> Cc: Linux-MIPS <linux-mips@linux-mips.org> Cc: Matthew Fortune <Matthew.Fortune@imgtec.com> Cc: Markos Chandras <Markos.Chandras@imgtec.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/8355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-08-02MIPS: init upper 64b of vector registers when MSA is first usedPaul Burton1-0/+5
When a task first makes use of MSA we need to ensure that the upper 64b of the vector registers are set to some value such that no information can be leaked to it from the previous task to use MSA context on the CPU. The architecture formerly specified that these bits would be cleared to 0 when a scalar FP instructions wrote to the aliased FP registers, which would have implicitly handled this as the kernel restored scalar FP context. However more recent versions of the specification now state that the value of the bits in such cases is unpredictable. Initialise them explictly to be sure, and set all the bits to 1 rather than 0 for consistency with the least significant 64b. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7497/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-08-02MIPS: preserve scalar FP CSR when switching vector contextPaul Burton1-1/+3
Switching the vector context implicitly saves & restores the state of the aliased scalar FP data registers, however the scalar FP control & status register is distinct from the MSA control & status register. In order to allow scalar FP to function correctly in programs using MSA, the scalar CSR needs to be saved & restored along with the MSA vector context. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7301/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-30MIPS: OCTEON: Enable use of FPUDavid Daney1-0/+3
Some versions of the assembler will not assemble CFC1 for OCTEON, so override the ISA for these. Add r4k_fpu.o to handle low level FPU initialization. Modify octeon_switch.S to save the FPU registers. And include r4k_switch.S to pick up more FPU support. Get rid of "#define cpu_has_fpu 0" Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Andreas Herrmann <andreas.herrmann@caviumnetworks.com> Cc: linux-mips@linux-mips.org Cc: James Hogan <james.hogan@imgtec.com> Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7006/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-24MIPS: MT: Remove SMTC supportRalf Baechle1-33/+0
Nobody is maintaining SMTC anymore and there also seems to be no userbase. Which is a pity - the SMTC technology primarily developed by Kevin D. Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT ASE's power and elegance. Based on Markos Chandras <Markos.Chandras@imgtec.com> patch https://patchwork.linux-mips.org/patch/6719/ which while very similar did no longer apply cleanly when I tried to merge it plus some additional post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to merge once upon a time. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-03-31MIPS: Fix gigaton of warning building with microMIPS.Ralf Baechle1-1/+1
With binutils 2.24 the attempt to switch with microMIPS mode to MIPS III mode through .set mips3 results in *lots* of warnings like {standard input}: Assembler messages: {standard input}:397: Warning: the 64-bit MIPS architecture does not support the `smartmips' extension during a kernel build. Fixed by using .set arch=r4000 instead. This breaks support for building the kernel with binutils 2.13 which was supported for 32 bit kernels only anyway and 2.14 which was a bad vintage for MIPS anyway. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-03-26MIPS: Basic MSA context switching supportPaul Burton1-17/+41
This patch adds support for context switching the MSA vector registers. These 128 bit vector registers are aliased with the FP registers - an FP register accesses the least significant bits of the vector register with which it is aliased (ie. the register with the same index). Due to both this & the requirement that the scalar FPU must be 64-bit (FR=1) if enabled at the same time as MSA the kernel will enable MSA & scalar FP at the same time for tasks which use MSA. If we restore the MSA vector context then we might as well enable the scalar FPU since the reason it was left disabled was to allow for lazy FP context restoring - but we just restored the FP context as it's a subset of the vector context. If we restore the FP context and have previously used MSA then we have to restore the whole vector context anyway (see comment in enable_restore_fp_context for details) so similarly we might as well enable MSA. Thus if a task does not use MSA then it will continue to behave as without this patch - the scalar FP context will be saved & restored as usual. But if a task executes an MSA instruction then it will save & restore the vector context forever more. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/6431/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-01-13MIPS: Support for 64-bit FP with O32 binariesPaul Burton1-2/+43
CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs do. In order to preserve backwards compatibility a 64-bit FPU will act like a 32-bit FPU (by accessing doubles from the least significant 32 bits of an even-odd pair of FP registers) when the Status.FR bit is zero, again just like a mips64 CPU. The standard O32 ABI is defined expecting a 32-bit FPU, however recent toolchains support use of a 64-bit FPU from an O32 MIPS32 executable. When an ELF executable is built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF header. With this patch the kernel will check the EF_MIPS_FP64 flag when executing an O32 binary, and set Status.FR accordingly. The addition of O32 64-bit FP support lessens the opportunity for optimisation in the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is introduced to allow this support to be disabled for those that don't require it. Inspired by an earlier patch by Leonid Yegoshin, but implemented more cleanly & correctly. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Paul Burton <paul.burton@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/6154/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-10-07MIPS: stack protector: Fix per-task canary switchJames Hogan1-1/+1
Commit 1400eb6 (MIPS: r4k,octeon,r2300: stack protector: change canary per task) was merged in v3.11 and introduced assembly in the MIPS resume functions to update the value of the current canary in __stack_chk_guard. However it used PTR_L resulting in a load of the canary value, instead of PTR_LA to construct its address. The value is intended to be random but is then treated as an address in the subsequent LONG_S (store). This was observed to cause a fault and panic: CPU 0 Unable to handle kernel paging request at virtual address 139fea20, epc == 8000cc0c, ra == 8034f2a4 Oops[#1]: ... $24 : 139fea20 1e1f7cb6 ... Call Trace: [<8000cc0c>] resume+0xac/0x118 [<8034f2a4>] __schedule+0x5f8/0x78c [<8034f4e0>] schedule_preempt_disabled+0x20/0x2c [<80348eec>] rest_init+0x74/0x84 [<804dc990>] start_kernel+0x43c/0x454 Code: 3c18804b 8f184030 8cb901f8 <af190000> 00c0e021 8cb002f0 8cb102f4 8cb202f8 8cb302fc This can also be forced by modifying arch/mips/include/asm/stackprotector.h so that the default __stack_chk_guard value is more likely to be a bad (or unaligned) pointer. Fix it to use PTR_LA instead, to load the address of the canary value, which the LONG_S can then use to write into it. Reported-by: bobjones (via #mipslinux on IRC) Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gregory Fong <gregory.0xf0@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/6026/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-07-01MIPS: r4k,octeon,r2300: stack protector: change canary per taskGregory Fong1-0/+6
For non-SMP, uses the new random canary value that is stored in the task struct whenever a new task is forked. Based on ARM version in df0698be14c6683606d5df2d83e3ae40f85ed0d9 and subject to the same limitations: the variable GCC expects, __stack_chk_guard, is global, so this will not work on SMP. Quoting Nicolas Pitre <nico@fluxnic.net>: "One way to overcome this GCC limitation would be to locate the __stack_chk_guard variable into a memory page of its own for each CPU, and then use TLB locking to have each CPU see its own page at the same virtual address for each of them." Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5488/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01MIPS: Whitespace cleanup.Ralf Baechle1-2/+2
Having received another series of whitespace patches I decided to do this once and for all rather than dealing with this kind of patches trickling in forever. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-12-28MIPS: Don't include <asm/page.h> unnecessarily.Ralf Baechle1-1/+0
So far we're jumping through hoops to keep the file usable from assembler source but it's getting just too painful. Turns out that many uses of <asm/page.h> are unnecessary anyway, so just remove those. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-07-19MIPS: Fix race condition with FPU thread task flag during context switch.Leonid Yegoshin1-9/+3
[ralf@linux-mips.org: Cosmetic changes; also fixed up r2300_switch.S and octeon_switch.S which needed similar modifications.] Signed-off-by: Leonid Yegoshin <yegoshin@mips.com> Signed-off-by: Steven J. Hill <sjhill@mips.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3784/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-04-06update David Miller's old email addressJustin P. Mattock1-1/+1
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-09-17MIPS: Consolidate all CONFIG_CPU_HAS_LLSC use in a single C file.Ralf Baechle1-3/+0
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-07-12[MIPS] Fix resume for 64K page size on R4000 class processors.Ralf Baechle1-6/+1
Problem reported by Peter Watkins <pwatkins@sicortex.com> but this is a different fix. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-06-06[MIPS] Remove duplicate fpu enable hazard code.Chris Dearman1-1/+1
Use common code from hazards.h instead. Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-04-20[MIPS] Disallow CpU exception in kernel again.Atsushi Nemoto1-6/+4
The commit 4d40bff7110e9e1a97ff8c01bdd6350e9867cc10 ("Allow CpU exception in kernel partially") was broken. The commit was to fix theoretical problem but broke usual case. Revert it for now. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-03-17[MIPS] FPU ownership management & preemption fixesAtsushi Nemoto1-4/+6
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-11-01[MIPS] 16K & 64K page size fixesRalf Baechle1-0/+5
Derived from Peter Watkins <treestem@gmail.com>'s work. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel1-1/+0
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-29[MIPS] Fix use of ehb instruction for non-R2 configurations.Ralf Baechle1-3/+3
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-06-19[MIPS] Fix fpu_save_double on 64-bit.Atsushi Nemoto1-5/+8
> Without this fix, _save_fp() in 64-bit kernel is seriously broken. > > ffffffff8010bec0 <_save_fp>: > ffffffff8010bec0: 400d6000 mfc0 t1,c0_status > ffffffff8010bec4: 000c7140 sll t2,t0,0x5 > ffffffff8010bec8: 05c10011 bgez t2,ffffffff8010bf10 <_save_fp+0x50> > ffffffff8010becc: 00000000 nop > ffffffff8010bed0: f4810328 sdc1 $f1,808(a0) > ... Fix register usage in fpu_save_double() and make fpu_restore_double() more symmetric with fpu_save_double(). Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2006-04-19[MIPS] MT: Improved multithreading support.Ralf Baechle1-1/+33
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2005-09-09kbuild: mips use generic asm-offsets.h supportSam Ravnborg1-1/+1
Removed obsolete stuff from arch makefile. mips had a special rule for generating asm-offsets.h so preserved it using an architecture specific hook in top-level Kbuild file. Renamed .h file to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-05[PATCH] mips: nuke trailing whitespaceRalf Baechle1-2/+2
Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-05[PATCH] mips: clean up 32/64-bit configurationRalf Baechle1-2/+2
Start cleaning 32-bit vs. 64-bit configuration. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds1-0/+221
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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