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path: root/arch/powerpc/kernel/head_book3s_32.S
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2022-12-08Merge branch 'topic/objtool' into nextMichael Ellerman
Merge the powerpc objtool support, which we were keeping in a topic branch in case of any merge conflicts.
2022-12-02powerpc: allow minimum sized kernel stack framesNicholas Piggin
This affects only 64-bit ELFv2 kernels, and reduces the minimum asm-created stack frame size from 112 to 32 byte on those kernels. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221127124942.1665522-16-npiggin@gmail.com
2022-11-18powerpc/32: Fix objtool unannotated intra-function call warningsChristophe Leroy
Fix several annotations in assembly files on PPC32. [Sathvika Vasireddy: Changed subject line and removed Kconfig change to enable objtool, as it is a part of "objtool/powerpc: Enable objtool to be built on ppc" patch in this series.] Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-7-sv@linux.ibm.com
2022-07-27powerpc/32: Set an IBAT covering up to _einittext during initChristophe Leroy
Always set an IBAT covering up to _einittext during init because when CONFIG_MODULES is not selected there is no reason to have an exception handler for kernel instruction TLB misses. It implies DBAT and IBAT are now totaly independent, IBATs are set by setibat() and DBAT by setbat(). This allows to revert commit 9bb162fa26ed ("powerpc/603: Fix boot failure with DEBUG_PAGEALLOC and KFENCE") Reported-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ce7f04a39593934d9b1ee68c69144ccd3d4da4a1.1655202804.git.christophe.leroy@csgroup.eu
2022-03-25Merge tag 'powerpc-5.18-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Livepatch support for 32-bit is probably the standout new feature, otherwise mostly just lots of bits and pieces all over the board. There's a series of commits cleaning up function descriptor handling, which touches a few other arches as well as LKDTM. It has acks from Arnd, Kees and Helge. Summary: - Enforce kernel RO, and implement STRICT_MODULE_RWX for 603. - Add support for livepatch to 32-bit. - Implement CONFIG_DYNAMIC_FTRACE_WITH_ARGS. - Merge vdso64 and vdso32 into a single directory. - Fix build errors with newer binutils. - Add support for UADDR64 relocations, which are emitted by some toolchains. This allows powerpc to build with the latest lld. - Fix (another) potential userspace r13 corruption in transactional memory handling. - Cleanups of function descriptor handling & related fixes to LKDTM. Thanks to Abdul Haleem, Alexey Kardashevskiy, Anders Roxell, Aneesh Kumar K.V, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chen Jingwen, Christophe JAILLET, Christophe Leroy, Corentin Labbe, Daniel Axtens, Daniel Henrique Barboza, David Dai, Fabiano Rosas, Ganesh Goudar, Guo Zhengkui, Hangyu Hua, Haren Myneni, Hari Bathini, Igor Zhbanov, Jakob Koschel, Jason Wang, Jeremy Kerr, Joachim Wiberg, Jordan Niethe, Julia Lawall, Kajol Jain, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mamatha Inamdar, Maxime Bizon, Maxim Kiselev, Maxim Kochetkov, Michal Suchanek, Nageswara R Sastry, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nour-eddine Taleb, Paul Menzel, Ping Fang, Pratik R. Sampat, Randy Dunlap, Ritesh Harjani, Rohan McLure, Russell Currey, Sachin Sant, Segher Boessenkool, Shivaprasad G Bhat, Sourabh Jain, Thierry Reding, Tobias Waldekranz, Tyrel Datwyler, Vaibhav Jain, Vladimir Oltean, Wedson Almeida Filho, and YueHaibing" * tag 'powerpc-5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (179 commits) powerpc/pseries: Fix use after free in remove_phb_dynamic() powerpc/time: improve decrementer clockevent processing powerpc/time: Fix KVM host re-arming a timer beyond decrementer range powerpc/tm: Fix more userspace r13 corruption powerpc/xive: fix return value of __setup handler powerpc/64: Add UADDR64 relocation support powerpc: 8xx: fix a return value error in mpc8xx_pic_init powerpc/ps3: remove unneeded semicolons powerpc/64: Force inlining of prevent_user_access() and set_kuap() powerpc/bitops: Force inlining of fls() powerpc: declare unmodified attribute_group usages const powerpc/spufs: Fix build warning when CONFIG_PROC_FS=n powerpc/secvar: fix refcount leak in format_show() powerpc/64e: Tie PPC_BOOK3E_64 to PPC_FSL_BOOK3E powerpc: Move C prototypes out of asm-prototypes.h powerpc/kexec: Declare kexec_paca static powerpc/smp: Declare current_set static powerpc: Cleanup asm-prototypes.c powerpc/ftrace: Use STK_GOT in ftrace_mprofile.S powerpc/ftrace: Regroup PPC64 specific operations in ftrace_mprofile.S ...
2022-02-07powerpc/32: Remove _ENTRY() macroChristophe Leroy
_ENTRY() is now redundant with _GLOBAL(). Remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62a35f8dde2bb74c8d0d7a5430cce07a5a3a6fb6.1638273868.git.christophe.leroy@csgroup.eu
2022-02-07powerpc/32: Remove remaining .stabs annotationsChristophe Leroy
STABS debug format has been superseded long time ago by DWARF. Remove the few remaining .stabs annotations from old 32 bits code. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/68932ec2ba6b868d35006b96e90f0890f3da3c05.1638273868.git.christophe.leroy@csgroup.eu
2022-02-07powerpc/603: Fix boot failure with DEBUG_PAGEALLOC and KFENCEChristophe Leroy
Allthough kernel text is always mapped with BATs, we still have inittext mapped with pages, so TLB miss handling is required when CONFIG_DEBUG_PAGEALLOC or CONFIG_KFENCE is set. The final solution should be to set a BAT that also maps inittext but that BAT then needs to be cleared at end of init, and it will require more changes to be able to do it properly. As DEBUG_PAGEALLOC or KFENCE are debugging, performance is not a big deal so let's fix it simply for now to enable easy stable application. Fixes: 035b19a15a98 ("powerpc/32s: Always map kernel text and rodata with BATs") Cc: stable@vger.kernel.org # v5.11+ Reported-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aea33b4813a26bdb9378b5f273f00bd5d4abe240.1638857364.git.christophe.leroy@csgroup.eu
2022-02-03powerpc/603: Clear C bit when PTE is read onlyChristophe Leroy
On book3s/32 MMU, PP bits don't offer kernel RO protection, kernel pages are always RW. However, on the 603 a page fault is always generated when the C bit (change bit = dirty bit) is not set. Enforce kernel RO protection by clearing C bit in TLB miss handler when the page doesn't have _PAGE_RW flag. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bbb13848ff0100a76ee9ea95118058c30ae95f2c.1643613343.git.christophe.leroy@csgroup.eu
2022-02-03powerpc/603: Remove outdated commentChristophe Leroy
Since commit 84de6ab0e904 ("powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.") page table is not updated anymore by TLB miss handlers. Remove the comment. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38b1ffefd2146fa56bf8aa605d476ad9736bbb37.1643613296.git.christophe.leroy@csgroup.eu
2021-12-09powerpc/32s: Do kuep_lock() and kuep_unlock() in assemblyChristophe Leroy
When interrupt and syscall entries where converted to C, KUEP locking and unlocking was also converted. It improved performance by unrolling the loop, and allowed easily implementing boot time deactivation of KUEP. However, null_syscall selftest shows that KUEP is still heavy (361 cycles with KUEP, 212 cycles without). A way to improve more is to group 'mtsr's together, instead of repeating 'addi' + 'mtsr' several times. In order to do that, more registers need to be available. In C, GCC will always be able to provide the requested number of registers, but at the cost of saving some data on the stack, which is counter performant here. So let's do it in assembly, when we have full control of which register can be used. It also has the advantage of locking earlier and unlocking later and it helps GCC generating less tricky code. The only drawback is to make boot time deactivation less straight forward and require 'hand' instruction patching. Group 'mtsr's by 4. With this change, null_syscall selftest reports 336 cycles. Without the change it was 361 cycles, that's a 7% reduction. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/115cb279e9b9948dfd93a065e047081c59e3a2a6.1634627931.git.christophe.leroy@csgroup.eu
2021-08-07powerpc/32s: Fix napping restore in data storage interrupt (DSI)Christophe Leroy
When a DSI (Data Storage Interrupt) is taken while in NAP mode, r11 doesn't survive the call to power_save_ppc32_restore(). So use r1 instead of r11 as they both contain the virtual stack pointer at that point. Fixes: 4c0104a83fc3 ("powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE") Cc: stable@vger.kernel.org # v5.13+ Reported-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/731694e0885271f6ee9ffc179eb4bcee78313682.1628003562.git.christophe.leroy@csgroup.eu
2021-06-25powerpc: Remove klimitChristophe Leroy
klimit is a global variable initialised at build time with the value of _end. This variable is never modified, so _end symbol can be used directly. Remove klimit. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9fa9ba6807c17f93f35a582c199c646c4a8bfd9c.1622800638.git.christophe.leroy@csgroup.eu
2021-06-17powerpc: Define swapper_pg_dir[] in CChristophe Leroy
Don't duplicate swapper_pg_dir[] in each platform's head.S Define it in mm/pgtable.c Define MAX_PTRS_PER_PGD because on book3s/64 PTRS_PER_PGD is not a constant. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5e3f1b8a4695c33ccc80aa3870e016bef32b85e1.1623063174.git.christophe.leroy@csgroup.eu
2021-06-17powerpc: Define empty_zero_page[] in CChristophe Leroy
At the time being, empty_zero_page[] is defined in each platform head.S. Define it in mm/mem.c instead, and put it in BSS section instead of the DATA section. Commit 5227cfa71f9e ("arm64: mm: place empty_zero_page in bss") explains why it is interesting to have it in BSS. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5838caffa269e0957c5a50cc85477876220298b0.1623063174.git.christophe.leroy@csgroup.eu
2021-06-17powerpc/32s: Initialise KUAP and KUEP in CChristophe Leroy
In order to selectively activate KUAP and KUEP in a following patch, perform KUAP and KUEP initialisation in C. Unlike PPC64, PPC32 doesn't have an early_setup_secondary(), so do it in start_secondary(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/87be72023448dd4e476744ed279b8c04b8d08a1c.1622708530.git.christophe.leroy@csgroup.eu
2021-06-17powerpc/32s: Convert switch_mmu_context() to CChristophe Leroy
switch_mmu_context() does things that can easily be done in C. For updating user segments, we have update_user_segments(). As mentionned in commit b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C"), update_user_segments() has the loop unrolled which is a significant performance gain. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/05c0875ad8220c03452c3a334946e207c6ca04d6.1622708530.git.christophe.leroy@csgroup.eu
2021-05-17powerpc/603: Avoid a pile of NOPs when not using SW LRU in TLB exceptionsChristophe Leroy
The SW LRU is in an MMU feature section. When not used, that's a dozen of NOPs to fetch for nothing. Define an ALT section that does the few remaining operations. That also avoids a double read on SRR1 in the SW LRU case. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/603725297466959419628ef7964aaf3417fb647d.1620363691.git.christophe.leroy@csgroup.eu
2021-05-17powerpc/32s: Remove m8260_gorom()Christophe Leroy
Last user of m8260_gorom() was removed by Commit 917f0af9e5a9 ("powerpc: Remove arch/ppc and include/asm-ppc") removed last user of m8260_gorom(). In fact m8260_gorom() was ported to arch/powerpc/ but the platform using it died with arch/ppc/ Remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/13f7532f21df3196e8c78b4f82a9c8d5487aca35.1620292185.git.christophe.leroy@csgroup.eu
2021-04-21powerpc/32s: Enhance readability of trap typesChristophe Leroy
This patch makes use of trap types in head_book3s_32.S Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bd80ace67757f489fc4ecdb76dd1a71511daba94.1618847273.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Remove the xfer parameter in EXCEPTION() macroChristophe Leroy
The xfer parameter is not used anymore, remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/17c7d68bd18f7d2f1ab24a1a20d9ed33bbcda741.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATEChristophe Leroy
In order to get more control in exception prolog, dismantle all non standard exception macros, finishing with EXC_XFER_STD and EXC_XFER_LITE and EXC_XFER_TEMPLATE. Also remove transfer_to_handler_full and ret_from_except and ret_from_except_full as they are not used anymore. Last parameter of EXCEPTION() is now ignored, will be removed in a later patch to avoid too much churn. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ca5795d04a220586b7037dbbbe6951dfa9e768eb.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Only restore non volatile registers when requiredChristophe Leroy
Until now, non volatile registers were restored everytime they were saved, ie using EXC_XFER_STD meant saving and restoring them while EXC_XFER_LITE meant neither saving not restoring them. Now that they are always saved, EXC_XFER_STD means to restore them and EXC_XFER_LITE means to not restore them. Most of the users of EXC_XFER_STD only need to retrieve the non volatile registers. For them there is no need to restore the non volatile registers as they have not been modified. Only very few exceptions require non volatile registers restore. Opencode the few places which require saving of non volatile registers. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d1cb12d8023cc6afc1f07150565571373c04945c.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Save trap number on stack in exception prologChristophe Leroy
Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Call bad_page_fault() from do_page_fault()Christophe Leroy
Now that non volatile registers are saved at all time, no need to split bad_page_fault() out of do_page_fault(). Remove handle_page_fault() and use do_page_fault() directly. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/cfb95be8863204cc2bf45a22ea44dd1d0dc16b7f.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Set regs parameter in r3 in transfer_to_handlerChristophe Leroy
All exception handlers take regs as first parameter. Instead of setting r3 just before each call to a handler, set it in transfer_to_handler. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f994a379bb895a2cbd518cb82460ad3f3d3ccdf5.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Provide a name to exception prolog continuation in virtual modeChristophe Leroy
Now that the prolog continuation is separated in .text, give it a name and mark it _ASM_NOKPROBE_SYMBOL. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d96374218815a6627e1e922ab2aba994050fb87a.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Move exception prolog code into .text once MMU is back onChristophe Leroy
The space in the head section is rather constrained by the fact that exception vectors are spread every 0x100 bytes and sometimes we need to have "out of line" code because it doesn't fit. Now that we are enabling MMU early in the prolog, take that opportunity to jump somewhere else in the .text section where we don't have any space constraint. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38b31ca4bc782a4985bc7952a675404d7ff27c24.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Use START_EXCEPTION() as much as possibleChristophe Leroy
Everywhere where it is possible, use START_EXCEPTION(). This will help for proper exception init in future patches. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d47c1cc242bbbef8658327503726abdaef9b63ef.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Add vmap_stack_overflow label inside the macroChristophe Leroy
For consistency, add in the macro the label used by exception prolog to branch to stack overflow processing. While at it, enclose the macro in #ifdef CONFIG_VMAP_STACK on the 8xx as already done on book3s/32. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/cf80056f5b946572ad98aea9d915dd25b23beda6.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Always enable data translation in exception prologChristophe Leroy
If the code can use a stack in vm area, it can also use a stack in linear space. Simplify code by removing old non VMAP stack code on PPC32. That means the data translation is now re-enabled early in exception prolog in all cases, not only when using VMAP stacks. While we are touching EXCEPTION_PROLOG macros, remove the unused for_rtas parameter in EXCEPTION_PROLOG_1. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu
2021-03-01powerpc/603: Fix protection of user pages mapped with PROT_NONEChristophe Leroy
On book3s/32, page protection is defined by the PP bits in the PTE which provide the following protection depending on the access keys defined in the matching segment register: - PP 00 means RW with key 0 and N/A with key 1. - PP 01 means RW with key 0 and RO with key 1. - PP 10 means RW with both key 0 and key 1. - PP 11 means RO with both key 0 and key 1. Since the implementation of kernel userspace access protection, PP bits have been set as follows: - PP00 for pages without _PAGE_USER - PP01 for pages with _PAGE_USER and _PAGE_RW - PP11 for pages with _PAGE_USER and without _PAGE_RW For kernelspace segments, kernel accesses are performed with key 0 and user accesses are performed with key 1. As PP00 is used for non _PAGE_USER pages, user can't access kernel pages not flagged _PAGE_USER while kernel can. For userspace segments, both kernel and user accesses are performed with key 0, therefore pages not flagged _PAGE_USER are still accessible to the user. This shouldn't be an issue, because userspace is expected to be accessible to the user. But unlike most other architectures, powerpc implements PROT_NONE protection by removing _PAGE_USER flag instead of flagging the page as not valid. This means that pages in userspace that are not flagged _PAGE_USER shall remain inaccessible. To get the expected behaviour, just mimic other architectures in the TLB miss handler by checking _PAGE_USER permission on userspace accesses as if it was the _PAGE_PRESENT bit. Note that this problem only is only for 603 cores. The 604+ have an hash table, and hash_page() function already implement the verification of _PAGE_USER permission on userspace pages. Fixes: f342adca3afc ("powerpc/32s: Prepare Kernel Userspace Access Protection") Cc: stable@vger.kernel.org # v5.2+ Reported-by: Christoph Plattner <christoph.plattner@thalesgroup.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4a0c6e3bb8f0c162457bf54d9bc6fd8d7b55129f.1612160907.git.christophe.leroy@csgroup.eu
2021-02-22Merge tag 'powerpc-5.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A large series adding wrappers for our interrupt handlers, so that irq/nmi/user tracking can be isolated in the wrappers rather than spread in each handler. - Conversion of the 32-bit syscall handling into C. - A series from Nick to streamline our TLB flushing when using the Radix MMU. - Switch to using queued spinlocks by default for 64-bit server CPUs. - A rework of our PCI probing so that it happens later in boot, when more generic infrastructure is available. - Two small fixes to allow 32-bit little-endian processes to run on 64-bit kernels. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Ananth N Mavinakayanahalli, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Cédric Le Goater, Chengyang Fan, Christophe Leroy, Christopher M. Riedl, Fabiano Rosas, Florian Fainelli, Frederic Barrat, Ganesh Goudar, Hari Bathini, Jiapeng Chong, Joseph J Allen, Kajol Jain, Markus Elfring, Michal Suchanek, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Pingfan Liu, Po-Hsu Lin, Qian Cai, Ram Pai, Randy Dunlap, Sandipan Das, Stephen Rothwell, Tyrel Datwyler, Will Springer, Yury Norov, and Zheng Yongjun. * tag 'powerpc-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (188 commits) powerpc/perf: Adds support for programming of Thresholding in P10 powerpc/pci: Remove unimplemented prototypes powerpc/uaccess: Merge raw_copy_to_user_allowed() into raw_copy_to_user() powerpc/uaccess: Merge __put_user_size_allowed() into __put_user_size() powerpc/uaccess: get rid of small constant size cases in raw_copy_{to,from}_user() powerpc/64: Fix stack trace not displaying final frame powerpc/time: Remove get_tbl() powerpc/time: Avoid using get_tbl() spi: mpc52xx: Avoid using get_tbl() powerpc/syscall: Avoid storing 'current' in another pointer powerpc/32: Handle bookE debugging in C in syscall entry/exit powerpc/syscall: Do not check unsupported scv vector on PPC32 powerpc/32: Remove the counter in global_dbcr0 powerpc/32: Remove verification of MSR_PR on syscall in the ASM entry powerpc/syscall: implement system call entry/exit logic in C for PPC32 powerpc/32: Always save non volatile GPRs at syscall entry powerpc/syscall: Change condition to check MSR_RI powerpc/syscall: Save r3 in regs->orig_r3 powerpc/syscall: Use is_compat_task() powerpc/syscall: Make interrupt.c buildable on PPC32 ...
2021-02-11powerpc/32: Preserve cr1 in exception prolog stack check to fix build errorChristophe Leroy
THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1 Maximum PAGE_SHIFT is 18 for 256k pages so THREAD_ALIGN_SHIFT is 19 at the maximum. No need to clobber cr1, it can be preserved when moving r1 into CR when we check stack overflow. This reduces the number of instructions in Machine Check Exception prolog and fixes a build failure reported by the kernel test robot on v5.10 stable when building with RTAS + VMAP_STACK + KVM. That build failure is due to too many instructions in the prolog hence not fitting between 0x200 and 0x300. Allthough the problem doesn't show up in mainline, it is still worth the change. Fixes: 98bf2d3f4970 ("powerpc/32s: Fix RTAS machine check with VMAP stack") Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ae4d545e3ac58e133d2599e0deb88843cb494fc.1612768623.git.christophe.leroy@csgroup.eu
2021-02-09powerpc: add and use unknown_async_exceptionNicholas Piggin
This is currently the same as unknown_exception, but it will diverge after interrupt wrappers are added and code moved out of asm into the wrappers (e.g., async handlers will check FINISH_NAP). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-22-npiggin@gmail.com
2021-02-09powerpc: remove arguments from fault handler functionsNicholas Piggin
Make mm fault handlers all just take the pt_regs * argument and load DAR/DSISR from that. Make those that return a value return long. This is done to make the function signatures match other handlers, which will help with a future patch to add wrappers. Explicit arguments could be added for performance but that would require more wrapper macro variants. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-7-npiggin@gmail.com
2021-02-09powerpc/32s: move DABR match out of handle_page_faultChristophe Leroy
handle_page_fault() has some code dedicated to book3s/32 to call do_break() when the DSI is a DABR match. On other platforms, do_break() is handled separately. Do the same for book3s/32, do it earlier in the process of DSI. This change also avoid doing the test on ISI. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-4-npiggin@gmail.com
2021-01-31powerpc/32s: Only build hash code when CONFIG_PPC_BOOK3S_604 is selectedChristophe Leroy
It is now possible to only build book3s/32 kernel for CPUs without hash table. Opt out hash related code when CONFIG_PPC_BOOK3S_604 is not selected. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62df436454ef06e104cc334a0859a2878d7888d5.1608274548.git.christophe.leroy@csgroup.eu
2021-01-04powerpc/32s: Fix RTAS machine check with VMAP stackChristophe Leroy
When we have VMAP stack, exception prolog 1 sets r1, not r11. When it is not an RTAS machine check, don't trash r1 because it is needed by prolog 1. Fixes: da7bb43ab9da ("powerpc/32: Fix vmap stack - Properly set r1 before activating MMU") Fixes: d2e006036082 ("powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Squash in fixup for RTAS machine check from Christophe] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bc77d61d1c18940e456a2dee464f1e2eda65a3f0.1608621048.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Handle PROTFAULT in hash_page() also for CONFIG_PPC_KUAPChristophe Leroy
On hash 32 bits, handling minor protection faults like unsetting dirty flag is heavy if done from the normal page_fault processing, because it implies hash table software lookup for flushing the entry and then a DSI is taken anyway to add the entry back. When KUAP was implemented, as explained in commit a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection"), protection faults has been diverted from hash_page() because hash_page() was not able to identify a KUAP fault. Implement KUAP verification in hash_page(), by clearing write permission when the access is a kernel access and Ks is 1. This works regardless of the address because kernel segments always have Ks set to 0 while user segments have Ks set to 0 only when kernel write to userspace is granted. Then protection faults can be handled by hash_page() even for KUAP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8a4ffe4798e9ea32aaaccdf85e411bb1beed3500.1605542955.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Make Hash var staticChristophe Leroy
Hash var is used only locally in mmu.c now. No need to set it in head_32.S anymore. Make it static and initialises it to the early hash table. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/786c82a89cdfdaabb32b72a44f7c312fa81d192b.1603348103.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/32s: Use SPRN_SPRG_SCRATCH2 in DSI prologChristophe Leroy
Use SPRN_SPRG_SCRATCH2 as an alternative scratch register in the early part of DSI prolog in order to avoid clobbering SPRN_SPRG_SCRATCH0/1 used by other prologs. The 603 doesn't like a jump from DataLoadTLBMiss to the 10 nops that are now in the beginning of DSI exception as a result of the feature section. To workaround this, add a jump as alternative. It also avoids fetching 10 nops for nothing. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f9f8df2a2be93568768ef1ac793639f7914cf103.1606285014.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/603: Use SPRN_SDR1 to store the pgdir phys addressChristophe Leroy
On the 603, SDR1 is not used. In order to free SPRN_SPRG2, use SPRN_SDR1 to store the pgdir phys addr. But only some bits of SDR1 can be used (0xffff01ff). As the pgdir is 4k aligned, rotate it by 4 bits to the left. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7370574b49d8476878ce5480726197993cb76108.1606285014.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/32s: Fix an FTR_SECTION_ELSEChristophe Leroy
An FTR_SECTION_ELSE is in the middle of BEGIN_MMU_FTR_SECTION/ALT_MMU_FTR_SECTION_END_IFSET Change it to MMU_FTR_SECTION_ELSE Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/61790f1a91692950a6bb5bb53d6d514d9bcdad74.1606285014.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/32s: Always map kernel text and rodata with BATsChristophe Leroy
Since commit 2b279c0348af ("powerpc/32s: Allow mapping with BATs with DEBUG_PAGEALLOC"), there is no real situation where mapping without BATs is required. In order to simplify memory handling, always map kernel text and rodata with BATs even when "nobats" kernel parameter is set. Also fix the 603 TLB miss exceptions that don't require anymore kernel page table if DEBUG_PAGEALLOC. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/da51f7ec632825a4ce43290a904aad61648408c0.1606285013.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832xChristophe Leroy
The e300c2 core which is embedded in mpc832x CPU doesn't have an FPU. Make it possible to not select CONFIG_PPC_FPU when building a kernel dedicated to that target. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fcdc60d85baf80eaa0a7f3261d9d889282068216.1597770847.git.christophe.leroy@csgroup.eu
2020-11-25Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch, in particular to bring in the changes for the entry/uaccess flush.
2020-11-19powerpc: Replace RFI by rfi on book3s/32 and bookeChristophe Leroy
For book3s/32 and for booke, RFI is just an rfi. Only 40x has a non trivial RFI. CONFIG_PPC_RTAS is never selected by 40x platforms. Make it more explicit by replacing RFI by rfi wherever possible. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b901ddfdeb8a0a3b7cb59999599cdfde1bbfe834.1604854583.git.christophe.leroy@csgroup.eu
2020-11-08powerpc/32s: Use relocation offset when setting early hash tableChristophe Leroy
When calling early_hash_table(), the kernel hasn't been yet relocated to its linking address, so data must be addressed with relocation offset. Add relocation offset to write into Hash in early_hash_table(). Fixes: 69a1593abdbc ("powerpc/32s: Setup the early hash table at all time.") Reported-by: Erhard Furtner <erhard_f@mailbox.org> Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Serge Belyshev <belyshev@depni.sinp.msu.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9e225a856a8b22e0e77587ee22ab7a2f5bca8753.1604740029.git.christophe.leroy@csgroup.eu
2020-11-05powerpc/603: Always fault when _PAGE_ACCESSED is not setChristophe Leroy
The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. Fixes: 84de6ab0e904 ("powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a44367744de54e2315b2f1a8cbbd7f88488072e0.1602342806.git.christophe.leroy@csgroup.eu
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