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2020-05-26powerpc: Add ppc_inst_next()Michael Ellerman
In a few places we want to calculate the address of the next instruction. Previously that was simple, we just added 4 bytes, or if using a u32 * we incremented that pointer by 1. But prefixed instructions make it more complicated, we need to advance by either 4 or 8 bytes depending on the actual instruction. We also can't do pointer arithmetic using struct ppc_inst, because it is always 8 bytes in size on 64-bit, even though we might only need to advance by 4 bytes. So add a ppc_inst_next() helper which calculates the location of the next instruction, if the given instruction was located at the given address. Note the instruction doesn't need to actually be at the address in memory. Although it would seem natural for the value to be passed by value, that makes it too easy to write a loop that will read off the end of a page, eg: for (; src < end; src = ppc_inst_next(src, *src), dest = ppc_inst_next(dest, *dest)) As noticed by Christophe and Jordan, if end is the exact end of a page, and the next page is not mapped, this will fault, because *dest will read 8 bytes, 4 bytes into the next page. So value is passed by reference, so the helper can be careful to use ppc_inst_read() on it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Jordan Niethe <jniethe5@gmail.com> Link: https://lore.kernel.org/r/20200522133318.1681406-1-mpe@ellerman.id.au
2020-05-26Merge branch 'fixes' into nextMichael Ellerman
Merge our fixes branch from this cycle. It contains several important fixes we need in next for testing purposes, and also some that will conflict with upcoming changes.
2020-05-26Merge "Use hugepages to map kernel mem on 8xx" into nextMichael Ellerman
Merge Christophe's large series to use huge pages for the linear mapping on 8xx. From his cover letter: The main purpose of this big series is to: - reorganise huge page handling to avoid using mm_slices. - use huge pages to map kernel memory on the 8xx. The 8xx supports 4 page sizes: 4k, 16k, 512k and 8M. It uses 2 Level page tables, PGD having 1024 entries, each entry covering 4M address space. Then each page table has 1024 entries. At the time being, page sizes are managed in PGD entries, implying the use of mm_slices as it can't mix several pages of the same size in one page table. The first purpose of this series is to reorganise things so that standard page tables can also handle 512k pages. This is done by adding a new _PAGE_HUGE flag which will be copied into the Level 1 entry in the TLB miss handler. That done, we have 2 types of pages: - PGD entries to regular page tables handling 4k/16k and 512k pages - PGD entries to hugepd tables handling 8M pages. There is no need to mix 8M pages with other sizes, because a 8M page will use more than what a single PGD covers. Then comes the second purpose of this series. At the time being, the 8xx has implemented special handling in the TLB miss handlers in order to transparently map kernel linear address space and the IMMR using huge pages by building the TLB entries in assembly at the time of the exception. As mm_slices is only for user space pages, and also because it would anyway not be convenient to slice kernel address space, it was not possible to use huge pages for kernel address space. But after step one of the series, it is now more flexible to use huge pages. This series drop all assembly 'just in time' handling of huge pages and use huge pages in page tables instead. Once the above is done, then comes icing on the cake: - Use huge pages for KASAN shadow mapping - Allow pinned TLBs with strict kernel rwx - Allow pinned TLBs with debug pagealloc Then, last but not least, those modifications for the 8xx allows the following improvement on book3s/32: - Mapping KASAN shadow with BATs - Allowing BATs with debug pagealloc All this allows to considerably simplify TLB miss handlers and associated initialisation. The overhead of reading page tables is negligible compared to the reduction of the miss handlers. While we were at touching pte_update(), some cleanup was done there too. Tested widely on 8xx and 832x. Boot tested on QEMU MAC99.
2020-05-26powerpc/32s: Implement dedicated kasan_init_region()Christophe Leroy
Implement a kasan_init_region() dedicated to book3s/32 that allocates KASAN regions using BATs. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/709e821602b48a1d7c211a9b156da26db98c3e9d.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/32s: Allow mapping with BATs with DEBUG_PAGEALLOCChristophe Leroy
DEBUG_PAGEALLOC only manages RW data. Text and RO data can still be mapped with BATs. In order to map with BATs, also enforce data alignment. Set by default to 256M which is a good compromise for keeping enough BATs for also KASAN and IMMR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fd29c1718ee44d82115d0e835ced808eb4ccbf51.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Implement dedicated kasan_init_region()Christophe Leroy
Implement a kasan_init_region() dedicated to 8xx that allocates KASAN regions using huge pages. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d2d60202a8821dc81cffe6ff59cc13c15b7e4bb6.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Allow large TLBs with DEBUG_PAGEALLOCChristophe Leroy
DEBUG_PAGEALLOC only manages RW data. Text and RO data can still be mapped with hugepages and pinned TLB. In order to map with hugepages, also enforce a 512kB data alignment minimum. That's a trade-off between size of speed, taking into account that DEBUG_PAGEALLOC is a debug option. Anyway the alignment is still tunable. We also allow tuning of alignment for book3s to limit the complexity of the test in Kconfig that will anyway disappear in the following patches once DEBUG_PAGEALLOC is handled together with BATs. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c13256f2d356a316715da61fe089b3623ef217a5.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Allow STRICT_KERNEL_RwX with pinned TLBChristophe Leroy
Pinned TLB are 8M. Now that there is no strict boundary anymore between text and RO data, it is possible to use 8M pinned executable TLB that covers both text and RO data. When PIN_TLB_DATA or PIN_TLB_TEXT is selected, enforce 8M RW data alignment and allow STRICT_KERNEL_RWX. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c535fc97bf0dd8693192e25feeed8088701e00c6.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Map linear memory with huge pagesChristophe Leroy
Map linear memory space with 512k and 8M pages whenever possible. Three mappings are performed: - One for kernel text - One for RO data - One for the rest Separating the mappings is done to be able to update the protection later when using STRICT_KERNEL_RWX. The ITLB miss handler now need to also handle huge TLBs unless kernel text in pinned. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c44f0ab5510474f25123d904cd1f4e5c6aa3c1ac.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Map IMMR with a huge pageChristophe Leroy
Map the IMMR area with a single 512k huge page. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9495dba06669da40e133f24607758fa6dcc65f66.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Add a function to early map kernel via huge pagesChristophe Leroy
Add a function to early map kernel memory using huge pages. For 512k pages, just use standard page table and map in using 512k pages. For 8M pages, create a hugepd table and populate the two PGD entries with it. This function can only be used to create page tables at startup. Once the regular SLAB allocation functions replace memblock functions, this function cannot allocate new pages anymore. However it can still update existing mappings with new protections. hugepd_none() macro is moved into asm/hugetlb.h to be usable outside of mm/hugetlbpage.c early_pte_alloc_kernel() is made visible. _PAGE_HUGE flag is now displayed by ptdump. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Change ptdump display to use "huge"] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/68325bcd3b6f93127f7810418a2352c3519066d6.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Refactor kernel address boundary comparisonChristophe Leroy
Now that linear and IMMR dedicated TLB handling is gone, kernel boundary address comparison is similar in ITLB miss handler and in DTLB miss handler. Create a macro named compare_to_kernel_boundary. When TASK_SIZE is strictly below 0x80000000 and PAGE_OFFSET is above 0x80000000, it is enough to compare to 0x8000000, and this can be done with a single instruction. Using not. instruction, we get to use 'blt' conditional branch as when doing a regular comparison: 0x00000000 <= addr <= 0x7fffffff ==> 0xffffffff >= NOT(addr) >= 0x80000000 The above test corresponds to a 'blt' Otherwise, do a regular comparison using two instructions. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6312575d06a8813105e6564a3b12e1d373aa1b2f.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Don't be too strict with _etext alignment on PPC32Christophe Leroy
Similar to PPC64, accept to map RO data as ROX as a trade off between between security and memory usage. Having RO data executable is not a high risk as RO data can't be modified to forge an exploit. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8c4a0d89d944eed984dd941e509614031a5ace2b.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Move DTLB perf handling closer.Christophe Leroy
Now that space have been freed next to the DTLB miss handler, it's associated DTLB perf handling can be brought back in the same place. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/97f48cc1a2ea6b895bfac0752cbe59deaf2eecda.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Remove now unused TLB miss functionsChristophe Leroy
The code to setup linear and IMMR mapping via huge TLB entries is not called anymore. Remove it. Also remove the handling of removed code exits in the perf driver. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/75750d25849cb8e73ca519866bb892d7eb9649c0.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Drop special handling of Linear and IMMR mappings in I/D TLB ↵Christophe Leroy
handlers Up to now, linear and IMMR mappings are managed via huge TLB entries through specific code directly in TLB miss handlers. This implies some patching of the TLB miss handlers at startup, and a lot of dedicated code. Remove all this specific dedicated code. For now we are back to normal handling via standard 4k pages. In the next patches, linear memory mapping and IMMR mapping will be managed through huge pages. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/221b7e3ead80a5969629938c023f8cfe45fdd2fb.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Always pin TLBs at startup.Christophe Leroy
At startup, map 32 Mbytes of memory through 4 pages of 8M, and PIN them inconditionnaly. They need to be pinned because KASAN is using page tables early and the TLBs might be dynamically replaced otherwise. Remove RSV4I flag after installing mappings unless CONFIG_PIN_TLB_XXXX is 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/b27c5767d18053b59f7eefddc189fcc3acf7b9c2.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Don't set IMMR map anymore at bootChristophe Leroy
Only early debug requires IMMR to be mapped early. No need to set it up and pin it in assembly. Map it through page tables at udbg init when necessary. If CONFIG_PIN_TLB_IMMR is selected, pin it once we don't need the 32 Mb pinned RAM anymore. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/13c1e8539fdf363d3146f4884e5c3c76c6c308b5.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Add function to set pinned TLBsChristophe Leroy
Pinned TLBs cannot be modified when the MMU is enabled. Create a function to rewrite the pinned TLB entries with MMU off. To set pinned TLB, we have to turn off MMU, disable pinning, do a TLB flush (Either with tlbie and tlbia) then reprogam the TLB entries, enable pinning and turn on MMU. If using tlbie, it cleared entries in both instruction and data TLB regardless whether pinning is disabled or not. If using tlbia, it clears all entries of the TLB which has disabled pinning. To make it easy, just clear all entries in both TLBs, and reprogram them. The function takes two arguments, the top of the memory to consider and whether data is RO under _sinittext. When DEBUG_PAGEALLOC is set, the top is the end of kernel rodata. Otherwise, that's the top of physical RAM. Everything below _sinittext is set RX, over _sinittext that's RW. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c17806014bb1c06513ad1e1d510faea31984b177.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Move PPC_PIN_TLB options into 8xx KconfigChristophe Leroy
PPC_PIN_TLB options are dedicated to the 8xx, move them into the 8xx Kconfig. While we are at it, add some text to explain what it does. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1ece39fac6312e1d14e6a67b3f9d9f9f91990a7b.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: MM_SLICE is not needed anymoreChristophe Leroy
As the 8xx now manages 512k pages in standard page tables, it doesn't need CONFIG_PPC_MM_SLICES anymore. Don't select it anymore and remove all related code. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/98e8ccd424476ea73cced2b89ba38eb2ed8144fb.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Only 8M pages are hugepte pages nowChristophe Leroy
512k pages are now standard pages, so only 8M pages are hugepte. No more handling of normal page tables through hugepd allocation and freeing, and hugepte helpers can also be simplified. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2c6135d57fb76eebf70673fbac3dc9e740767879.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Manage 512k huge pages as standard pages.Christophe Leroy
At the time being, 512k huge pages are handled through hugepd page tables. The PMD entry is flagged as a hugepd pointer and it means that only 512k hugepages can be managed in that 4M block. However, the hugepd table has the same size as a normal page table, and 512k entries can therefore be nested with normal pages. On the 8xx, TLB loading is performed by software and allthough the page tables are organised to match the L1 and L2 level defined by the HW, all TLB entries have both L1 and L2 independent entries. It means that even if two TLB entries are associated with the same PMD entry, they can be loaded with different values in L1 part. The L1 entry contains the page size (PS field): - 00 for 4k and 16 pages - 01 for 512k pages - 11 for 8M pages By adding a flag for hugepages in the PTE (_PAGE_HUGE) and copying it into the lower bit of PS, we can then manage 512k pages with normal page tables: - PMD entry has PS=11 for 8M pages - PMD entry has PS=00 for other pages. As a PMD entry covers 4M areas, a PMD will either point to a hugepd table having a single entry to an 8M page, or the PMD will point to a standard page table which will have either entries to 4k or 16k or 512k pages. For 512k pages, as the L1 entry will not know it is a 512k page before the PTE is read, there will be 128 entries in the PTE as if it was 4k pages. But when loading the TLB, it will be flagged as a 512k page. Note that we can't use pmd_ptr() in asm/nohash/32/pgtable.h because it is not defined yet. In ITLB miss, we keep the possibility to opt it out as when kernel text is pinned and no user hugepages are used, we can save several instruction by not using r11. In DTLB miss, that's just one instruction so it's not worth bothering with 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/002819e8e166bf81d24b24782d98de7c40905d8f.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.Christophe Leroy
Prepare ITLB handler to handle _PAGE_HUGE when CONFIG_HUGETLBFS is enabled. This means that the L1 entry has to be kept in r11 until L2 entry is read, in order to insert _PAGE_HUGE into it. Also move pgd_offset helpers before pte_update() as they will be needed there in next patch. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/21fd1de8fba781bededa9474a5a9374aefb1f849.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/8xx: Drop CONFIG_8xx_COPYBACK optionChristophe Leroy
CONFIG_8xx_COPYBACK was there to help disabling copyback cache mode for debuging hardware. But nobody will design new boards with 8xx now. All 8xx platforms select it, so make it the default and remove the option. Also remove the Mx_RESETVAL values which are pretty useless and hide the real value while reading code. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bcc968cda075516eb76e2f25e09821f582c566b4.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Reduce hugepd size for 8M hugepages on 8xxChristophe Leroy
Commit 55c8fc3f4930 ("powerpc/8xx: reintroduce 16K pages with HW assistance") redefined pte_t as a struct of 4 pte_basic_t, because in 16K pages mode there are four identical entries in the page table. But hugepd entries for 8M pages require only one entry of size pte_basic_t. So there is no point in creating a cache for 4 entries page tables. Calculate PTE_T_ORDER using the size of pte_basic_t instead of pte_t. Define specific huge_pte helpers (set_huge_pte_at(), huge_pte_clear(), huge_ptep_set_wrprotect()) to write the pte in a single entry instead of using set_pte_at() which writes 4 identical entries in 16k pages mode. Also make sure that __ptep_set_access_flags() properly handle the huge_pte case. Define set_pte_filter() inline otherwise GCC doesn't inline it anymore because it is now used twice, and that gives a pretty suboptimal code because of pte_t being a struct of 4 entries. Those functions are also used for 512k pages which only require one entry as well allthough replicating it four times was harmless as 512k pages entries are spread every 128 bytes in the 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/43050d1a0c2d6e1541cab9c1126fc80bc7015ebd.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Create a dedicated pte_update() for 8xxChristophe Leroy
pte_update() is a bit special for the 8xx. At the time being, that's an #ifdef inside the nohash/32 pte_update(). As we are going to make it even more special in the coming patches, create a dedicated version for pte_update() for 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a103be0099ac2360f8c44f4a1a63cc03713a1360.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Standardise pte_update() prototype between PPC32 and PPC64Christophe Leroy
PPC64 takes 3 additional parameters compared to PPC32: - mm - address - huge These 3 parameters will be needed in order to perform different action depending on the page size on the 8xx. Make pte_update() prototype identical for PPC32 and PPC64. This allows dropping an #ifdef in huge_ptep_get_and_clear(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38111acf6841047a8addde37c63e92d611ee38c2.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Standardise __ptep_test_and_clear_young() params between PPC32 ↵Christophe Leroy
and PPC64 On PPC32, __ptep_test_and_clear_young() takes the mm->context.id In preparation of standardising pte_update() params between PPC32 and PPC64, __ptep_test_and_clear_young() need mm instead of mm->context.id Replace context param by mm. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0a65470e50a14373b7c2291184514aa982462255.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Refactor pte_update() on book3s/32Christophe Leroy
When CONFIG_PTE_64BIT is set, pte_update() operates on 'unsigned long long' When CONFIG_PTE_64BIT is not set, pte_update() operates on 'unsigned long' In asm/page.h, we have pte_basic_t which is 'unsigned long long' when CONFIG_PTE_64BIT is set and 'unsigned long' otherwise. Refactor pte_update() using pte_basic_t. While we are at it, drop the comment on 44x which is not applicable to book3s version of pte_update(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c78912bc8613fb249c3d80aeb1062796b5c49400.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Refactor pte_update() on nohash/32Christophe Leroy
When CONFIG_PTE_64BIT is set, pte_update() operates on 'unsigned long long' When CONFIG_PTE_64BIT is not set, pte_update() operates on 'unsigned long' In asm/page.h, we have pte_basic_t which is 'unsigned long long' when CONFIG_PTE_64BIT is set and 'unsigned long' otherwise. Refactor pte_update() using pte_basic_t. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/590d67994a2847cd9fe088f7d974499e3a18b6ac.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: PTE_ATOMIC_UPDATES is only for 40xChristophe Leroy
Only 40x still uses PTE_ATOMIC_UPDATES. 40x cannot not select CONFIG_PTE64_BIT. Drop handling of PTE_ATOMIC_UPDATES: - In nohash/64 - In nohash/32 for CONFIG_PTE_64BIT Keep PTE_ATOMIC_UPDATES only for nohash/32 for !CONFIG_PTE_64BIT Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d6f8e1f46583f1842de24581a68b0496feb15516.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Fix conditions to perform MMU specific management by blocks on ↵Christophe Leroy
PPC32. Setting init mem to NX shall depend on sinittext being mapped by block, not on stext being mapped by block. Setting text and rodata to RO shall depend on stext being mapped by block, not on sinittext being mapped by block. Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX") 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/7d565fb8f51b18a3d98445a830b2f6548cb2da2a.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/mm: Allocate static page tables for fixmapChristophe Leroy
Allocate static page tables for the fixmap area. This allows setting mappings through page tables before memblock is ready. That's needed to use early_ioremap() early and to use standard page mappings with fixmap. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4f4b1412d34de6801b8e925cb88fc69d056ff536.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/32s: Don't warn when mapping RO data ROX.Christophe Leroy
Mapping RO data as ROX is not an issue since that data cannot be modified to introduce an exploit. PPC64 accepts to have RO data mapped ROX, as a trade off between kernel size and strictness of protection. On PPC32, kernel size is even more critical as amount of memory is usually small. Depending on the number of available IBATs, the last IBATs might overflow the end of text. Only warn if it crosses the end of RO data. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6499f8eeb2a36330e5c9fc1cee9a79374875bd54.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/ptdump: Handle hugepd at PGD levelChristophe Leroy
The 8xx is about to map kernel linear space and IMMR using huge pages. In order to display those pages properly, ptdump needs to handle hugepd tables at PGD level. For the time being do it only at PGD level. Further patches may add handling of hugepd tables at lower level for other platforms when needed in the future. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/630728289158dcfeb06b14d40ed7c4c4e7148cf1.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/ptdump: Properly handle non standard page sizeChristophe Leroy
In order to properly display information regardless of the page size, it is necessary to take into account real page size. Fixes: cabe8138b23c ("powerpc: dump as a single line areas mapping a single physical page.") 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/a53b2a0ffd042a8d85464bf90d55bc5b970e00a1.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/ptdump: Standardise display of BAT flagsChristophe Leroy
Display BAT flags the same way as page flags: rwx and wimg Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a07585f353c167b8db9597d83f992a5cb4fbf4c4.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/ptdump: Display size of BATsChristophe Leroy
Display the size of areas mapped with BATs. For that, the size display for pages is refactorised. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/acf764eee231f0358e66ca9e819f052804055acc.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/ptdump: Add _PAGE_COHERENT flagChristophe Leroy
For platforms using shared.c (4xx, Book3e, Book3s/32), also handle the _PAGE_COHERENT flag which corresponds to the M bit of the WIMG flags. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Make it more verbose, use "coherent" rather than "m"] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/324c3d860717e8e91fca3bb6c0f8b23e1644a404.1589866984.git.christophe.leroy@csgroup.eu
2020-05-26powerpc/64s: Fix restore of NV GPRs after facility unavailable exceptionMichael Ellerman
Commit 702f09805222 ("powerpc/64s/exception: Remove lite interrupt return") changed the interrupt return path to not restore non-volatile registers by default, and explicitly restore them in paths where it is required. But it missed that the facility unavailable exception can sometimes modify user registers, ie. when it does emulation of move from DSCR. This is seen as a failure of the dscr_sysfs_thread_test: test: dscr_sysfs_thread_test [cpu 0] User DSCR should be 1 but is 0 failure: dscr_sysfs_thread_test So restore non-volatile GPRs after facility unavailable exceptions. Currently the hypervisor facility unavailable exception is also wired up to call facility_unavailable_exception(). In practice we should never take a hypervisor facility unavailable exception for the DSCR. On older bare metal systems we set HFSCR_DSCR unconditionally in __init_HFSCR, or on newer systems it should be enabled via the "data-stream-control-register" device tree CPU feature. Even if it's not, since commit f3c99f97a3cd ("KVM: PPC: Book3S HV: Don't access HFSCR, LPIDR or LPCR when running nested"), the KVM code has unconditionally set HFSCR_DSCR when running guests. So we should only get a hypervisor facility unavailable for the DSCR if skiboot has disabled the "data-stream-control-register" feature, and we are somehow in guest context but not via KVM. Given all that, it should be unnecessary to add a restore of non-volatile GPRs after the hypervisor facility exception, because we never expect to hit that path. But equally we may as well add the restore, because we never expect to hit that path, and if we ever did, at least we would correctly restore the registers to their post emulation state. In future we can split the non-HV and HV facility unavailable handling so that there is no emulation in the HV handler, and then remove the restore for the HV case. Fixes: 702f09805222 ("powerpc/64s/exception: Remove lite interrupt return") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200526061808.2472279-1-mpe@ellerman.id.au
2020-05-22powerpc/64s: Disable STRICT_KERNEL_RWXMichael Ellerman
Several strange crashes have been eventually traced back to STRICT_KERNEL_RWX and its interaction with code patching. Various paths in our ftrace, kprobes and other patching code need to be hardened against patching failures, otherwise we can end up running with partially/incorrectly patched ftrace paths, kprobes or jump labels, which can then cause strange crashes. Although fixes for those are in development, they're not -rc material. There also seem to be problems with the underlying strict RWX logic, which needs further debugging. So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from enabling the option and tripping over the bugs. Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs") Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au
2020-05-20powerpc/kasan: Declare kasan_init_region() weakChristophe Leroy
In order to alloc sub-arches to alloc KASAN regions using optimised methods (Huge pages on 8xx, BATs on BOOK3S, ...), declare kasan_init_region() weak. Also make kasan_init_shadow_page_tables() accessible from outside, so that it can be called from the specific kasan_init_region() functions if needed. And populate remaining KASAN address space only once performed the region mapping, to allow 8xx to allocate hugepd instead of standard page tables for mapping via 8M hugepages. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3c1ce419fa1b5a4171b92d7fb16455ca17e1b96d.1589866984.git.christophe.leroy@csgroup.eu
2020-05-20powerpc/kasan: Refactor update of early shadow mappingsChristophe Leroy
kasan_remap_early_shadow_ro() and kasan_unmap_early_shadow_vmalloc() are both updating the early shadow mapping: the first one sets the mapping read-only while the other clears the mapping. Refactor and create kasan_update_early_region() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8c496c0828de2608c7c940c45525d177e91b6f1b.1589866984.git.christophe.leroy@csgroup.eu
2020-05-20powerpc/kasan: Remove unnecessary page table lockingChristophe Leroy
Commit 45ff3c559585 ("powerpc/kasan: Fix parallel loading of modules.") added spinlocks to manage parallele module loading. Since then commit 47febbeeec44 ("powerpc/32: Force KASAN_VMALLOC for modules") converted the module loading to KASAN_VMALLOC. The spinlocking has then become unneeded and can be removed to simplify kasan_init_shadow_page_tables() Also remove inclusion of linux/moduleloader.h and linux/vmalloc.h which are not needed anymore since the removal of modules management. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/81a4d3aee8b82bc1355595935c8f4ad9d3b22a83.1589866984.git.christophe.leroy@csgroup.eu
2020-05-20powerpc/kasan: Fix shadow pages allocation failureChristophe Leroy
Doing kasan pages allocation in MMU_init is too early, kernel doesn't have access yet to the entire memory space and memblock_alloc() fails when the kernel is a bit big. Do it from kasan_init() instead. Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") 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/c24163ee5d5f8cdf52fefa45055ceb35435b8f15.1589866984.git.christophe.leroy@csgroup.eu
2020-05-20powerpc/kasan: Fix issues by lowering KASAN_SHADOW_ENDChristophe Leroy
At the time being, KASAN_SHADOW_END is 0x100000000, which is 0 in 32 bits representation. This leads to a couple of issues: - kasan_remap_early_shadow_ro() does nothing because the comparison k_cur < k_end is always false. - In ptdump, address comparison for markers display fails and the marker's name is printed at the start of the KASAN area instead of being printed at the end. However, there is no need to shadow the KASAN shadow area itself, so the KASAN shadow area can stop shadowing memory at the start of itself. With a PAGE_OFFSET set to 0xc0000000, KASAN shadow area is then going from 0xf8000000 to 0xff000000. Fixes: cbd18991e24f ("powerpc/mm: Fix an Oops in kasan_mmu_init()") 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/ae1a3c0d19a37410c209c3fc453634cfcc0ee318.1589866984.git.christophe.leroy@csgroup.eu
2020-05-20powerpc/kasan: Fix error detection on memory allocationChristophe Leroy
In case (k_start & PAGE_MASK) doesn't equal (kstart), 'va' will never be NULL allthough 'block' is NULL Check the return of memblock_alloc() directly instead of the resulting address in the loop. Fixes: 509cd3f2b473 ("powerpc/32: Simplify KASAN init") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7cb8ca82042bfc45a5cfe726c921cd7e7eeb12a3.1589866984.git.christophe.leroy@csgroup.eu
2020-05-20powerpc/64s/hash: Add stress_slb kernel boot option to increase SLB faultsNicholas Piggin
This option increases the number of SLB misses by limiting the number of kernel SLB entries, and increased flushing of cached lookaside information. This helps stress test difficult to hit paths in the kernel. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Relocate the code into arch/powerpc/mm, s/torture/stress/] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200511125825.3081305-1-mpe@ellerman.id.au
2020-05-20ocxl: Fix misleading commentAndrew Donnellan
In ocxl_context_free() we note that the AFU reference we're releasing was taken in "ocxl_context_init", a function that no longer exists. Fix it to say ocxl_context_alloc() instead, which is the new name for ocxl_context_init(), since it was renamed. Fixes: b9721d275cc2 ("ocxl: Allow external drivers to use OpenCAPI contexts") Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200226043923.5481-1-ajd@linux.ibm.com
generated by cgit (git 2.34.1) at 2025-03-28 19:54:20 +0000