- 15 Sep, 2020 34 commits
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Christophe Leroy authored
cpu_has_feature(CPU_FTR_SPE) returns false when CONFIG_SPE is not set. There is no need to enclose the test in an #ifdef CONFIG_SPE. Remove it. CPU_FTR_SPE only exists on 32 bits. Define it as 0 on 64 bits. We have a couple of places like: #ifdef CONFIG_SPE if (cpu_has_feature(CPU_FTR_SPE)) { do_something_that_requires_CONFIG_SPE } else { return -EINVAL; } #else return -EINVAL; #endif Replace them by a cleaner version: if (cpu_has_feature(CPU_FTR_SPE)) { #ifdef CONFIG_SPE do_something_that_requires_CONFIG_SPE #endif } else { return -EINVAL; } When CONFIG_SPE is not set, this resolves to an unconditional return of -EINVAL Signed-off-by:Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/698df8387555765b70ea42e4a7fa48141c309c1f.1597643221.git.christophe.leroy@csgroup.eu
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Christophe Leroy authored
cpu_has_feature(CPU_FTR_ALTIVEC) returns false when CONFIG_ALTIVEC is not set. There is no need to enclose the test in an #ifdef CONFIG_ALTIVEC. Remove it. Signed-off-by:
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Christophe Leroy authored
cpu_has_feature(CPU_FTR_VSX) returns false when CONFIG_VSX is not set. There is no need to enclose the test in an #ifdef CONFIG_VSX. Remove it. Signed-off-by:
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Christophe Leroy authored
That #endif is more than 100 lines after the matching #ifdef, and there are several #ifdef/#else/#endif inbetween. Tag it as /* CONFIG_PPC_BOOK3S_64 */ to help locate the matching #ifdef. Signed-off-by:
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Christophe Leroy authored
The #ifdef CONFIG_KALLSYMS encloses some printk which can compile in all cases. Replace by IS_ENABLED(). Signed-off-by:
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Christophe Leroy authored
The #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) encloses some printk which can be compiled in all cases. Replace by IS_ENABLED(). Signed-off-by:
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Christophe Leroy authored
This #ifdef CONFIG_PPC_BOOK3S_64 calls preload_new_slb_context() when radix is not enabled. radix_enabled() is always defined, and the prototype for preload_new_slb_context() is always present, so the #ifdef is unneeded. Replace it by IS_ENABLED(). Signed-off-by:
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Christophe Leroy authored
isync() is always defined, no need for an #ifdef. Replace it by IS_ENABLED(CONFIG_PPC_47x). Signed-off-by:
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Christophe Leroy authored
We need r1 to be properly set before activating MMU, otherwise any new exception taken while saving registers into the stack in exception prologs will use the user stack, which is wrong and will even lockup or crash when KUAP is selected. Do that by switching the meaning of r11 and r1 until we have saved r1 to the stack: copy r1 into r11 and setup the new stack pointer in r1. To avoid complicating and impacting all generic and specific prolog code (and more), copy back r1 into r11 once r11 is save onto the stack. We could get rid of copying r1 back and forth at the cost of rewriting everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK is set, but the effort is probably not worth it. Fixes: 02847487 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org Signed-off-by:
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Christophe Leroy authored
We need r1 to be properly set before activating MMU, so reading task_struct->stack must be done with MMU off. This means we need an additional register to play with MSR bits while r11 now points to the stack. For that, move r10 back to CR (As is already done for hash MMU) and use r10. We still don't have r1 correct yet when we activate MMU. It is done in following patch. Fixes: 02847487 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org Signed-off-by:
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Christophe Leroy authored
__put_user_asm() and __put_user_asm2() are not used anymore. Remove them. Signed-off-by:
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Christophe Leroy authored
__patch_instruction() is the only user of __put_user_asm() outside of asm/uaccess.h Switch to the new __put_user_asm_goto() to enable retirement of __put_user_asm() in a later patch. Signed-off-by:
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Christophe Leroy authored
__put_user_asm_goto() provides more flexibility to GCC and avoids using a local variable to tell if the write succeeded or not. GCC can then avoid implementing a cmp in the fast path. See the difference for a small function like the PPC64 version of save_general_regs() in arch/powerpc/kernel/signal_32.c: Before the patch (unreachable nop removed): 0000000000000c10 <.save_general_regs>: c10: 39 20 00 2c li r9,44 c14: 39 40 00 00 li r10,0 c18: 7d 29 03 a6 mtctr r9 c1c: 38 c0 00 00 li r6,0 c20: 48 00 00 14 b c34 <.save_general_regs+0x24> c30: 42 40 00 40 bdz c70 <.save_general_regs+0x60> c34: 28 2a 00 27 cmpldi r10,39 c38: 7c c8 33 78 mr r8,r6 c3c: 79 47 1f 24 rldicr r7,r10,3,60 c40: 39 20 00 01 li r9,1 c44: 41 82 00 0c beq c50 <.save_general_regs+0x40> c48: 7d 23 38 2a ldx r9,r3,r7 c4c: 79 29 00 20 clrldi r9,r9,32 c50: 91 24 00 00 stw r9,0(r4) c54: 2c 28 00 00 cmpdi r8,0 c58: 39 4a 00 01 addi r10,r10,1 c5c: 38 84 00 04 addi r4,r4,4 c60: 41 82 ff d0 beq c30 <.save_general_regs+0x20> c64: 38 60 ff f2 li r3,-14 c68: 4e 80 00 20 blr c70: 38 60 00 00 li r3,0 c74: 4e 80 00 20 blr 0000000000000000 <.fixup>: cc: 39 00 ff f2 li r8,-14 d0: 48 00 00 00 b d0 <.fixup+0xd0> d0: R_PPC64_REL24 .text+0xc54 After the patch: 0000000000001490 <.save_general_regs>: 1490: 39 20 00 2c li r9,44 1494: 39 40 00 00 li r10,0 1498: 7d 29 03 a6 mtctr r9 149c: 60 00 00 00 nop 14a0: 28 2a 00 27 cmpldi r10,39 14a4: 79 48 1f 24 rldicr r8,r10,3,60 14a8: 39 20 00 01 li r9,1 14ac: 41 82 00 0c beq 14b8 <.save_general_regs+0x28> 14b0: 7d 23 40 2a ldx r9,r3,r8 14b4: 79 29 00 20 clrldi r9,r9,32 14b8: 91 24 00 00 stw r9,0(r4) 14bc: 39 4a 00 01 addi r10,r10,1 14c0: 38 84 00 04 addi r4,r4,4 14c4: 42 00 ff dc bdnz 14a0 <.save_general_regs+0x10> 14c8: 38 60 00 00 li r3,0 14cc: 4e 80 00 20 blr 14d0: 38 60 ff f2 li r3,-14 14d4: 4e 80 00 20 blr Signed-off-by: -
Christophe Leroy authored
Enable pre-update addressing mode in __put_user_asm_goto() Signed-off-by:
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Christophe Leroy authored
The 8xx has 4 page sizes: 4k, 16k, 512k and 8M 4k and 16k can be selected at build time as standard page sizes, and 512k and 8M are hugepages. When 4k standard pages are selected, 16k pages are not available. Allow 16k pages as hugepages when 4k pages are used. To allow that, implement arch_make_huge_pte() which receives the necessary arguments to allow setting the PTE in accordance with the page size: - 512 k pages must have _PAGE_HUGE and _PAGE_SPS. They are set by pte_mkhuge(). arch_make_huge_pte() does nothing. - 16 k pages must have only _PAGE_SPS. arch_make_huge_pte() clears _PAGE_HUGE. Signed-off-by:
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Christophe Leroy authored
On 8xx, the number of entries occupied by a PTE in the page tables depends on the size of the page. At the time being, this calculation is done in two places: in pte_update() and in set_huge_pte_at() Refactor this calculation into a helper called number_of_cells_per_pte(). For the time being, the val param is unused. It will be used by following patch. Instead of opencoding is_hugepd(), use hugepd_ok() with a forward declaration. Signed-off-by:
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Christophe Leroy authored
The following random segfault is observed from time to time with map_hugetlb selftest: root@localhost:~# ./map_hugetlb 1 19 524288 kB hugepages Mapping 1 Mbytes Segmentation fault [ 31.219972] map_hugetlb[365]: segfault (11) at 117 nip 77974f8c lr 779a6834 code 1 in ld-2.23.so[77966000+21000] [ 31.220192] map_hugetlb[365]: code: 9421ffc0 480318d1 93410028 90010044 9361002c 93810030 93a10034 93c10038 [ 31.220307] map_hugetlb[365]: code: 93e1003c 93210024 8123007c 81430038 <80e90004> 814a0004 7f443a14 813a0004 [ 31.221911] BUG: Bad rss-counter state mm:(ptrval) type:MM_FILEPAGES val:33 [ 31.229362] BUG: Bad rss-counter state mm:(ptrval) type:MM_ANONPAGES val:5 This fault is due to hugetlb_free_pgd_range() freeing page tables that are also used by regular pages. As explain in the comment at the beginning of hugetlb_free_pgd_range(), the verification done in free_pgd_range() on floor and ceiling is not done here, which means hugetlb_free_pte_range() can free outside the expected range. As the verification cannot be done in hugetlb_free_pgd_range(), it must be done in hugetlb_free_pte_range(). Fixes: b250c8c0 ("powerpc/8xx: Manage 512k huge pages as standard pages.") Cc: stable@vger.kernel.org Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by:
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Finn Thain authored
Enabling CONFIG_TAU_INT causes random crashes: Unrecoverable exception 1700 at c0009414 (msr=1000) Oops: Unrecoverable exception, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac-00043-gd5f545e1a8593 #5 NIP: c0009414 LR: c0009414 CTR: c00116fc REGS: c0799eb8 TRAP: 1700 Not tainted (5.7.0-pmac-00043-gd5f545e1a8593) MSR: 00001000 <ME> CR: 22000228 XER: 00000100 GPR00: 00000000 c0799f70 c076e300 00800000 0291c0ac 00e00000 c076e300 00049032 GPR08: 00000001 c00116fc 00000000 dfbd3200 ffffffff 007f80a8 00000000 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 c075ce04 GPR24: c075ce04 dfff8880 c07b0000 c075ce04 00080000 00000001 c079ef98 c079ef5c NIP [c0009414] arch_cpu_idle+0x24/0x6c LR [c0009414] arch_cpu_idle+0x24/0x6c Call Trace: [c0799f70] [00000001] 0x1 (unreliable) [c0799f80] [c0060990] do_idle+0xd8/0x17c [c0799fa0] [c0060ba4] cpu_startup_entry+0x20/0x28 [c0799fb0] [c072d220] start_kernel+0x434/0x44c [c0799ff0] [00003860] 0x3860 Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX 3d20c07b XXXXXXXX XXXXXXXX XXXXXXXX 7c0802a6 XXXXXXXX XXXXXXXX XXXXXXXX 4e800421 XXXXXXXX XXXXXXXX XXXXXXXX 7d2000a6 ---[ end trace 3a0c9b5cb216db6b ]--- Resolve this problem by disabling each THRMn comparator when handling the associated THRMn interrupt and by disabling the TAU entirely when updating THRMn thresholds. Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
Finn Thain <fthain@telegraphics.com.au> Tested-by:
Stan Johnson <userm57@yahoo.com> Signed-off-by:
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Finn Thain authored
According to Freescale's documentation, MPC74XX processors have an erratum that prevents the TAU interrupt from working, so don't try to use it when running on those processors. Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
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Finn Thain authored
The commentary at the call site seems to disagree with the code. The conditional prevents calling set_thresholds() via the exception handler, which appears to crash. Perhaps that's because it immediately triggers another TAU exception. Anyway, calling set_thresholds() from TAUupdate() is redundant because tau_timeout() does so. Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
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Finn Thain authored
Since commit 19dbdcb8 ("smp: Warn on function calls from softirq context") the Thermal Assist Unit driver causes a warning like the following when CONFIG_SMP is enabled. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/smp.c:428 smp_call_function_many_cond+0xf4/0x38c Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-pmac #3 NIP: c00b37a8 LR: c00b3abc CTR: c001218c REGS: c0799c60 TRAP: 0700 Not tainted (5.7.0-pmac) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42000224 XER: 00000000 GPR00: c00b3abc c0799d18 c076e300 c079ef5c c0011fec 00000000 00000000 00000000 GPR08: 00000100 00000100 00008000 ffffffff 42000224 00000000 c079d040 c079d044 GPR16: 00000001 00000000 00000004 c0799da0 c079f054 c07a0000 c07a0000 00000000 GPR24: c0011fec 00000000 c079ef5c c079ef5c 00000000 00000000 00000000 00000000 NIP [c00b37a8] smp_call_function_many_cond+0xf4/0x38c LR [c00b3abc] on_each_cpu+0x38/0x68 Call Trace: [c0799d18] [ffffffff] 0xffffffff (unreliable) [c0799d68] [c00b3abc] on_each_cpu+0x38/0x68 [c0799d88] [c0096704] call_timer_fn.isra.26+0x20/0x7c [c0799d98] [c0096b40] run_timer_softirq+0x1d4/0x3fc [c0799df8] [c05b4368] __do_softirq+0x118/0x240 [c0799e58] [c0039c44] irq_exit+0xc4/0xcc [c0799e68] [c000ade8] timer_interrupt+0x1b0/0x230 [c0799ea8] [c0013520] ret_from_except+0x0/0x14 --- interrupt: 901 at arch_cpu_idle+0x24/0x6c LR = arch_cpu_idle+0x24/0x6c [c0799f70] [00000001] 0x1 (unreliable) [c0799f80] [c0060990] do_idle+0xd8/0x17c [c0799fa0] [c0060ba8] cpu_startup_entry+0x24/0x28 [c0799fb0] [c072d220] start_kernel+0x434/0x44c [c0799ff0] [00003860] 0x3860 Instruction dump: 8129f204 2f890000 40beff98 3d20c07a 8929eec4 2f890000 40beff88 0fe00000 81220000 552805de 550802ef 4182ff84 <0fe00000> 3860ffff 7f65db78 7f44d378 ---[ end trace 34a886e47819c2eb ]--- Don't call on_each_cpu() from a timer callback, call it from a worker thread instead. Fixes: 1da177e4 ("Linux-2.6.12-rc2") Tested-by:
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Finn Thain authored
According to the MPC750 Users Manual, the SITV value in Thermal Management Register 3 is 13 bits long. The present code calculates the SITV value as 60 * 500 cycles. This would overflow to give 10 us on a 500 MHz CPU rather than the intended 60 us. (But according to the Microprocessor Datasheet, there is also a factor of 266 that has to be applied to this value on certain parts i.e. speed sort above 266 MHz.) Always use the maximum cycle count, as recommended by the Datasheet. Fixes: 1da177e4 ("Linux-2.6.12-rc2") Signed-off-by:
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Aneesh Kumar K.V authored
MAX_PHYSMEM #define is used along with sparsemem to determine the SECTION_SHIFT value. Powerpc also uses the same value to limit the max memory enabled on the system. With 4K PAGE_SIZE and hash translation mode, we want to limit the max memory enabled to 64TB due to page table size restrictions. However, with radix translation, we don't have these restrictions. Hence split the radix and hash MA_PHYSMEM limit and use different limit for each of them. Signed-off-by:
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Aneesh Kumar K.V authored
With commit: 0034d395 ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range"), we now split the 64TB address range into 4 contexts each of 16TB. That implies we can do only 16TB linear mapping. On some systems, eg. Power9, memory attached to nodes > 0 will appear above 16TB in the linear mapping. This resulted in kernel crash when we boot such systems in hash translation mode with 4K PAGE_SIZE. This patch updates the kernel mapping such that we now start supporting upto 61TB of memory with 4K. The kernel mapping now looks like below 4K PAGE_SIZE and hash translation. vmalloc start = 0xc0003d0000000000 IO start = 0xc0003e0000000000 vmemmap start = 0xc0003f0000000000 Our MAX_PHYSMEM_BITS for 4K is still 64TB even though we can only map 61TB. We prevent bolt mapping anything outside 61TB range by checking against H_VMALLOC_START. Fixes: 0034d395 ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range") Reported-by:
Cameron Berkenpas <cam@neo-zeon.de> Signed-off-by:
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Aneesh Kumar K.V authored
Implement page mapping percpu first chunk allocator as a fallback to the embedding allocator. With 4K hash translation we limit our page table range to 64TB and commit: 0034d395 ("powerpc/mm/hash64: Map all the kernel regions in the same 0xc range") moved all kernel mapping to that 64TB range. In-order to support sparse memory layout we need to increase our linear mapping space and reduce other mappings. With such a layout percpu embedded first chunk allocator will fail because of small vmalloc range. Add a fallback to page mapping percpu first chunk allocator for such failures. The below dmesg output can be observed in such case. percpu: max_distance=0x1ffffef00000 too large for vmalloc space 0x10000000000 PERCPU: auto allocator failed (-22), falling back to page size percpu: 40 4K pages/cpu s148816 r0 d15024 Signed-off-by:
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Aneesh Kumar K.V authored
This update the ppc64 version to be closer to x86/sparc. Signed-off-by:
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Ravi Bangoria authored
Introduce tests to cover simple scenarios where user is watching memory which can be accessed by kernel as well. We also support _MODE_EXACT with _SETHWDEBUG interface. Move those testcases outside of _BP_RANGE condition. This will help to test _MODE_EXACT scenarios when CONFIG_HAVE_HW_BREAKPOINT is not set, eg: $ ./ptrace-hwbreak ... PTRACE_SET_DEBUGREG, Kernel Access Userspace, len: 8: Ok PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok PPC_PTRACE_SETHWDEBUG, MODE_EXACT, Kernel Access Userspace, len: 1: Ok success: ptrace-hwbreak Suggested-by:
Pedro Miraglia Franco de Carvalho <pedromfc@linux.ibm.com> Signed-off-by:
Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by:
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Ravi Bangoria authored
PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 can be used to determine whether we are running on an ISA 3.1 compliant machine. Which is needed to determine DAR behaviour, 512 byte boundary limit etc. This was requested by Pedro Miraglia Franco de Carvalho for extending watchpoint features in gdb. Note that availability of 2nd DAWR is independent of this flag and should be checked using ppc_debug_info->num_data_bps. Signed-off-by:
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Ravi Bangoria authored
There are couple of places where we set len but not hw_len. For ptrace/perf watchpoints, when CONFIG_HAVE_HW_BREAKPOINT=Y, hw_len will be calculated and set internally while parsing watchpoint. But when CONFIG_HAVE_HW_BREAKPOINT=N, we need to manually set 'hw_len'. Similarly for xmon as well, hw_len needs to be set directly. Fixes: b57aeab8 ("powerpc/watchpoint: Fix length calculation for unaligned target") Signed-off-by:
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Ravi Bangoria authored
On powerpc, ptrace watchpoint works in one-shot mode. i.e. kernel disables event every time it fires and user has to re-enable it. Also, in case of ptrace watchpoint, kernel notifies ptrace user before executing instruction. With CONFIG_HAVE_HW_BREAKPOINT=N, kernel is missing to disable ptrace event and thus it's causing infinite loop of exceptions. This is especially harmful when user watches on a data which is also read/written by kernel, eg syscall parameters. In such case, infinite exceptions happens in kernel mode which causes soft-lockup. Fixes: 9422de3e ("powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers") Reported-by:
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Ravi Bangoria authored
Power10 hw has multiple DAWRs but hw doesn't tell which DAWR caused the exception. So we have a sw logic to detect that in hw_breakpoint.c. But hw_breakpoint.c gets compiled only with CONFIG_HAVE_HW_BREAKPOINT=Y. Move DAWR detection logic outside of hw_breakpoint.c so that it can be reused when CONFIG_HAVE_HW_BREAKPOINT is not set. Signed-off-by:
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Ravi Bangoria authored
When kernel is compiled with CONFIG_HAVE_HW_BREAKPOINT=N, user can still create watchpoint using PPC_PTRACE_SETHWDEBUG, with limited functionalities. But, such watchpoints are never firing because of the missing privilege settings. Fix that. It's safe to set HW_BRK_TYPE_PRIV_ALL because we don't really leak any kernel address in signal info. Setting HW_BRK_TYPE_PRIV_ALL will also help to find scenarios when kernel accesses user memory. Reported-by:
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Ravi Bangoria authored
Vector load/store instructions are special because they are always aligned. Thus unaligned EA needs to be aligned down before comparing it with watch ranges. Otherwise we might consider valid event as invalid. Fixes: 74c68810 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint") Signed-off-by:
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Ravi Bangoria authored
On p10 predecessors, watchpoint with quadword access is compared at quadword length. If the watch range is doubleword or less than that in a first half of quadword aligned 16 bytes, and if there is any unaligned quadword access which will access only the 2nd half, the handler should consider it as extraneous and emulate/single-step it before continuing. Fixes: 74c68810 ("powerpc/watchpoint: Prepare handler to handle more than one watchpoint") Reported-by:
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- 14 Sep, 2020 3 commits
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Thiago Jung Bauermann authored
POWER secure guests (i.e., guests which use the Protected Execution Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but they don't need the SWIOTLB memory to be in low addresses since the hypervisor doesn't have any addressing limitation. This solves a SWIOTLB initialization problem we are seeing in secure guests with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved memory, which leaves no space for SWIOTLB in low addresses. To do this, we use mostly the same code as swiotlb_init(), but allocate the buffer using memblock_alloc() instead of memblock_alloc_low(). Fixes: 2efbc58f ("powerpc/pseries/svm: Force SWIOTLB for secure guests") Signed-off-by:
Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
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Michael Ellerman authored
When we added the VDSO32 kconfig symbol, which controls building of the 32-bit VDSO, we made it depend on CPU_BIG_ENDIAN (for 64-bit). That was because back then COMPAT was always enabled for 64-bit, so depending on it would have left the 32-bit VDSO always enabled, which we didn't want. But since then we have made COMPAT selectable, and off by default for ppc64le, so VDSO32 should really depend on that. For most people this makes no difference, none of the defconfigs change, it's only if someone is building ppc64le with COMPAT=y, they will now also get VDSO32. If they've enabled COMPAT in order to run 32-bit binaries they presumably also want the 32-bit VDSO. Signed-off-by:
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Michael Ellerman authored
Bring in our fixes branch for this cycle which avoids some small conflicts with upcoming commits.
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- 09 Sep, 2020 1 commit
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Vaibhav Jain authored
The newly introduced 'perf_stats' attribute uses the default access mode of 0444, allowing non-root users to access performance stats of an nvdimm and potentially force the kernel into issuing a large number of expensive hypercalls. Since the information exposed by this attribute cannot be cached it is better to ward off access to this attribute from users who don't need to access to these performance statistics. Hence update the access mode of 'perf_stats' attribute to be only readable by root users. Fixes: 2d02bf83 ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP") Reported-by:
Vaibhav Jain <vaibhav@linux.ibm.com> Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Signed-off-by:
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- 08 Sep, 2020 2 commits
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Nicholas Piggin authored
The ISA v3.1 the copy-paste facility has a new memory move functionality which allows the copy buffer to be pasted to domestic memory (RAM) as opposed to foreign memory (accelerator). This means the POWER9 trick of avoiding the cp_abort on context switch if the process had not mapped foreign memory does not work on POWER10. Do the cp_abort unconditionally there. KVM must also cp_abort on guest exit to prevent copy buffer state leaking between contexts. Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Acked-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
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Joel Stanley authored
It's not done anything for a long time. Save the percpu variable, and emit a warning to remind users to not expect it to do anything. This uses pr_warn_once instead of pr_warn_ratelimit as testing 'ppc64_cpu --smt=off' on a 24 core / 4 SMT system showed the warning to be noisy, as the online/offline loop is slow. Fixes: 3fa8cad8 ("powerpc/pseries/cpuidle: smt-snooze-delay cleanup.") Cc: stable@vger.kernel.org # v3.14 Signed-off-by:
Joel Stanley <joel@jms.id.au> Acked-by:
Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by:
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