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2021-03-29powerpc/32: Call bad_page_fault() from do_page_fault()Christophe Leroy6-25/+9
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 Leroy7-34/+5
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: Don't save thread.regs on interrupt entryChristophe Leroy1-4/+1
Since commit 06d67d54741a ("powerpc: make process.c suitable for both 32-bit and 64-bit"), thread.regs is set on task creation, no need to set it again and again at each interrupt entry as it never change. Suggested-by: Nicholas Piggin <npiggin@gmail.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/20d52c627303d63e461797df13e6890fc04017d0.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Replace ASM exception exit by C exception exit from ppc64Christophe Leroy2-319/+123
This patch replaces the PPC32 ASM exception exit by C exception exit. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/48f8bae91da899d8e73fc0d75c9af66cc97b4d5b.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Always save non volatile registers on exception entryChristophe Leroy3-15/+3
In preparation of handling exception entry and exit in C, in order to simplify the handling, always save non volatile registers when entering an exception. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3ce8ced87a4f1467fa36fcc50763d53b45e466c1.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Perform normal function call in exception entryChristophe Leroy3-15/+9
Now that the MMU is re-enabled before calling the transfer function, we don't need anymore that hack with the address of the handler and the return function sitting just after the 'bl' to the transfer fonction, that function is retrieving via a read relative to 'lr'. Do a regular call to the transfer function, then to the handler, then branch to the return function. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/73c00f3361ca280ef8fd7814c291bd1f5b6e2081.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Refactor booke critical registers savingChristophe Leroy2-33/+41
Refactor booke critical registers saving into a few macros and move it into the exception prolog directly. Keep the dedicated transfert_to_handler entry point for the moment allthough they are empty. They will be removed in a later patch to reduce 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/269171496f1f5f22afa621695bded22976c9d48d.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Provide a name to exception prolog continuation in virtual modeChristophe Leroy4-27/+31
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 Leroy4-34/+36
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 Leroy3-47/+22
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 Leroy3-3/+4
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: Statically initialise first emergency contextChristophe Leroy2-6/+2
The check of the emergency context initialisation in vmap_stack_overflow is buggy for the SMP case, as it compares r1 with 0 while in the SMP case r1 is offseted by the CPU id. Instead of fixing it, just perform static initialisation of the first emergency context. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4a67ba422be75713286dca0c86ee0d3df2eb6dfa.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Enable instruction translation at the same time as data translationChristophe Leroy4-28/+31
On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. In syscall handler, MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. Just update msr. Also update comment in power_save_ppc32_restore(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5269c7e5f5d2117358af3a89744d75a116be27b0.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xxChristophe Leroy2-12/+12
8xx requires to tag the DAR with a magic value in order to fixup DAR on faults generated by 'dcbX', as the 8xx forgets to update the DAR for those faults. Do the tagging as early as possible, that is before enabling MMU. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/853a2e28ca7c5fc85617037030f99fe6070c9536.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Always enable data translation in exception prologChristophe Leroy10-199/+16
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
2021-03-29powerpc/32: Remove ksp_limitChristophe Leroy7-97/+2
ksp_limit is there to help detect stack overflows. That is specific to ppc32 as it was removed from ppc64 in commit cbc9565ee826 ("powerpc: Remove ksp_limit on ppc64"). There are other means for detecting stack overflows. As ppc64 has proven to not need it, ppc32 should be able to do without it too. Lets remove it and simplify exception handling. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d789c3385b22e07bedc997613c0d26074cb513e7.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xxChristophe Leroy1-0/+2
8xx has registers SPRN_NRI, SPRN_EID and SPRN_EIE for changing MSR EE and RI. Use SPRN_EID in exception prolog to set RI. On an 8xx, it reduces the null_syscall test by 3 cycles. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/65f6bda827c2a2abce71ea7e07543e791163da33.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Handle bookE debugging in C in exception entryChristophe Leroy1-23/+0
The handling of SPRN_DBCR0 and other registers can easily be done in C instead of ASM. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6d6b2497115890b90cfa72a2b3ab1da5f78123c2.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Entry cpu time accounting in CChristophe Leroy1-1/+0
There is no need for this to be in asm, use the new interrupt entry wrapper. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/daca4c3e05cdfe54d237162a0718b3aaca897662.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Reconcile interrupts in CChristophe Leroy1-58/+0
There is no need for this to be in asm anymore, use the new interrupt entry wrapper. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/602e1ec47e15ca540f7edb9cf6feb6c249911bd6.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/40x: Prepare normal exception handler for enabling MMU earlyChristophe Leroy3-13/+21
Ensure normal exception handler are able to manage stuff with MMU enabled. For that we use CONFIG_VMAP_STACK related code allthough there is no intention to really activate CONFIG_VMAP_STACK on powerpc 40x for the moment. 40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of SPRN_DSISR. Take it into account in common macros. 40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in common macros that will be used also with 40x. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/01963af2b83037bca270d7bf1336ffcf35da8282.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/40x: Prepare for enabling MMU in critical exception prologChristophe Leroy1-3/+37
In order the enable MMU early in exception prolog, implement CONFIG_VMAP_STACK principles in critical exception prolog. There is no intention to use CONFIG_VMAP_STACK on 40x, but related code will be used to enable MMU early in exception in a later patch. Also address (critirq_ctx - PAGE_OFFSET) directly instead of using tophys() in order to win one instruction. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3fd75ee54c48307119acdbf66cfea966c1463bbd.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/40x: Reorder a few instructions in critical exception prologChristophe Leroy1-4/+4
In order to ease preparation for CONFIG_VMAP_STACK, reorder a few instruction, especially save r1 into stack frame earlier. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c895ecf958c86d1736bdd2ff6f36626b55f35fd2.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exceptionChristophe Leroy2-9/+8
In order to be able to switch MMU on in exception prolog, save SRR0 and SRR1 earlier. Also save r10 and r11 into stack earlier to better match with the normal exception prolog. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/79a93f253d72dc97ac968c9c62b5066960b688ed.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macroChristophe Leroy1-35/+36
Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro to remove the ugly ; and \ on each line. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/73291fb9dc9ec58182c27a40dfc3db204e3f4024.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlersChristophe Leroy1-21/+18
SPRN_SPRG_SCRATCH5 is used to save SPRN_PID. SPRN_SPRG_SCRATCH6 is already available. SPRN_PID is only 8 bits. We have r12 that contains CR. We only need to preserve CR0, so we have space available in r12 to save PID. Keep PID in r12 and free up SPRN_SPRG_SCRATCH5. Then In TLB miss handlers, instead of using SPRN_SPRG_SCRATCH0 and SPRN_SPRG_SCRATCH1, use SPRN_SPRG_SCRATCH5 and SPRN_SPRG_SCRATCH6 to avoid future conflicts with normal exception prologs. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4cdaa85d38e14d594ba902424060ec55babf2c42.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/traps: Declare unrecoverable_exception() as __noreturnChristophe Leroy1-1/+4
unrecoverable_exception() is never expected to return, most callers have an infiniteloop in case it returns. Ensure it really never returns by terminating it with a BUG(), and declare it __no_return. It always GCC to really simplify functions calling it. In the exemple below, it avoids the stack frame in the likely fast path and avoids code duplication for the exit. With this patch: 00000348 <interrupt_exit_kernel_prepare>: 348: 81 43 00 84 lwz r10,132(r3) 34c: 71 48 00 02 andi. r8,r10,2 350: 41 82 00 2c beq 37c <interrupt_exit_kernel_prepare+0x34> 354: 71 4a 40 00 andi. r10,r10,16384 358: 40 82 00 20 bne 378 <interrupt_exit_kernel_prepare+0x30> 35c: 80 62 00 70 lwz r3,112(r2) 360: 74 63 00 01 andis. r3,r3,1 364: 40 82 00 28 bne 38c <interrupt_exit_kernel_prepare+0x44> 368: 7d 40 00 a6 mfmsr r10 36c: 7c 11 13 a6 mtspr 81,r0 370: 7c 12 13 a6 mtspr 82,r0 374: 4e 80 00 20 blr 378: 48 00 00 00 b 378 <interrupt_exit_kernel_prepare+0x30> 37c: 94 21 ff f0 stwu r1,-16(r1) 380: 7c 08 02 a6 mflr r0 384: 90 01 00 14 stw r0,20(r1) 388: 48 00 00 01 bl 388 <interrupt_exit_kernel_prepare+0x40> 388: R_PPC_REL24 unrecoverable_exception 38c: 38 e2 00 70 addi r7,r2,112 390: 3d 00 00 01 lis r8,1 394: 7c c0 38 28 lwarx r6,0,r7 398: 7c c6 40 78 andc r6,r6,r8 39c: 7c c0 39 2d stwcx. r6,0,r7 3a0: 40 a2 ff f4 bne 394 <interrupt_exit_kernel_prepare+0x4c> 3a4: 38 60 00 01 li r3,1 3a8: 4b ff ff c0 b 368 <interrupt_exit_kernel_prepare+0x20> Without this patch: 00000348 <interrupt_exit_kernel_prepare>: 348: 94 21 ff f0 stwu r1,-16(r1) 34c: 93 e1 00 0c stw r31,12(r1) 350: 7c 7f 1b 78 mr r31,r3 354: 81 23 00 84 lwz r9,132(r3) 358: 71 2a 00 02 andi. r10,r9,2 35c: 41 82 00 34 beq 390 <interrupt_exit_kernel_prepare+0x48> 360: 71 29 40 00 andi. r9,r9,16384 364: 40 82 00 28 bne 38c <interrupt_exit_kernel_prepare+0x44> 368: 80 62 00 70 lwz r3,112(r2) 36c: 74 63 00 01 andis. r3,r3,1 370: 40 82 00 3c bne 3ac <interrupt_exit_kernel_prepare+0x64> 374: 7d 20 00 a6 mfmsr r9 378: 7c 11 13 a6 mtspr 81,r0 37c: 7c 12 13 a6 mtspr 82,r0 380: 83 e1 00 0c lwz r31,12(r1) 384: 38 21 00 10 addi r1,r1,16 388: 4e 80 00 20 blr 38c: 48 00 00 00 b 38c <interrupt_exit_kernel_prepare+0x44> 390: 7c 08 02 a6 mflr r0 394: 90 01 00 14 stw r0,20(r1) 398: 48 00 00 01 bl 398 <interrupt_exit_kernel_prepare+0x50> 398: R_PPC_REL24 unrecoverable_exception 39c: 80 01 00 14 lwz r0,20(r1) 3a0: 81 3f 00 84 lwz r9,132(r31) 3a4: 7c 08 03 a6 mtlr r0 3a8: 4b ff ff b8 b 360 <interrupt_exit_kernel_prepare+0x18> 3ac: 39 02 00 70 addi r8,r2,112 3b0: 3d 40 00 01 lis r10,1 3b4: 7c e0 40 28 lwarx r7,0,r8 3b8: 7c e7 50 78 andc r7,r7,r10 3bc: 7c e0 41 2d stwcx. r7,0,r8 3c0: 40 a2 ff f4 bne 3b4 <interrupt_exit_kernel_prepare+0x6c> 3c4: 38 60 00 01 li r3,1 3c8: 4b ff ff ac b 374 <interrupt_exit_kernel_prepare+0x2c> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1e883e9d93fdb256853d1434c8ad77c257349b2d.1615552866.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/uprobes: Validation for prefixed instructionRavi Bangoria1-0/+7
As per ISA 3.1, prefixed instruction should not cross 64-byte boundary. So don't allow Uprobe on such prefixed instruction. There are two ways probed instruction is changed in mapped pages. First, when Uprobe is activated, it searches for all the relevant pages and replace instruction in them. In this case, if that probe is on the 64-byte unaligned prefixed instruction, error out directly. Second, when Uprobe is already active and user maps a relevant page via mmap(), instruction is replaced via mmap() code path. But because Uprobe is invalid, entire mmap() operation can not be stopped. In this case just print an error and continue. Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210311091538.368590-1-ravi.bangoria@linux.ibm.com
2021-03-29powerpc/signal: Use __get_user() to copy sigset_tChristopher M. Riedl3-3/+10
Usually sigset_t is exactly 8B which is a "trivial" size and does not warrant using __copy_from_user(). Use __get_user() directly in anticipation of future work to remove the trivial size optimizations from __copy_from_user(). The ppc32 implementation of get_sigset_t() previously called copy_from_user() which, unlike __copy_from_user(), calls access_ok(). Replacing this w/ __get_user() (no access_ok()) is fine here since both callsites in signal_32.c are preceded by an earlier access_ok(). Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-11-cmr@codefail.de
2021-03-29powerpc/signal64: Rewrite rt_sigreturn() to minimise uaccess switchesDaniel Axtens1-4/+6
Add uaccess blocks and use the 'unsafe' versions of functions doing user access where possible to reduce the number of times uaccess has to be opened/closed. Co-developed-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-10-cmr@codefail.de
2021-03-29powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switchesDaniel Axtens1-21/+36
Add uaccess blocks and use the 'unsafe' versions of functions doing user access where possible to reduce the number of times uaccess has to be opened/closed. There is no 'unsafe' version of copy_siginfo_to_user, so move it slightly to allow for a "longer" uaccess block. Co-developed-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-9-cmr@codefail.de
2021-03-29powerpc/signal64: Replace restore_sigcontext() w/ unsafe_restore_sigcontext()Christopher M. Riedl1-27/+41
Previously restore_sigcontext() performed a costly KUAP switch on every uaccess operation. These repeated uaccess switches cause a significant drop in signal handling performance. Rewrite restore_sigcontext() to assume that a userspace read access window is open by replacing all uaccess functions with their 'unsafe' versions. Modify the callers to first open, call unsafe_restore_sigcontext(), and then close the uaccess window. Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-8-cmr@codefail.de
2021-03-29powerpc/signal64: Replace setup_sigcontext() w/ unsafe_setup_sigcontext()Christopher M. Riedl1-27/+45
Previously setup_sigcontext() performed a costly KUAP switch on every uaccess operation. These repeated uaccess switches cause a significant drop in signal handling performance. Rewrite setup_sigcontext() to assume that a userspace write access window is open by replacing all uaccess functions with their 'unsafe' versions. Modify the callers to first open, call unsafe_setup_sigcontext() and then close the uaccess window. Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-7-cmr@codefail.de
2021-03-29powerpc/signal64: Remove TM ifdefery in middle of if/else blockChristopher M. Riedl2-51/+54
Both rt_sigreturn() and handle_rt_signal_64() contain TM-related ifdefs which break-up an if/else block. Provide stubs for the ifdef-guarded TM functions and remove the need for an ifdef in rt_sigreturn(). Rework the remaining TM ifdef in handle_rt_signal64() similar to commit f1cf4f93de2f ("powerpc/signal32: Remove ifdefery in middle of if/else"). Unlike in the commit for ppc32, the ifdef can't be removed entirely since uc_transact in sigframe depends on CONFIG_PPC_TRANSACTIONAL_MEM. Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-6-cmr@codefail.de
2021-03-29powerpc/signal64: Remove non-inline calls from setup_sigcontext()Christopher M. Riedl1-11/+21
The majority of setup_sigcontext() can be refactored to execute in an "unsafe" context assuming an open uaccess window except for some non-inline function calls. Move these out into a separate prepare_setup_sigcontext() function which must be called first and before opening up a uaccess window. Non-inline function calls should be avoided during a uaccess window for a few reasons: - KUAP should be enabled for as much kernel code as possible. Opening a uaccess window disables KUAP which means any code executed during this time contributes to a potential attack surface. - Non-inline functions default to traceable which means they are instrumented for ftrace. This adds more code which could run with KUAP disabled. - Powerpc does not currently support the objtool UACCESS checks. All code running with uaccess must be audited manually which means: less code -> less work -> fewer problems (in theory). A follow-up commit converts setup_sigcontext() to be "unsafe". Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-4-cmr@codefail.de
2021-03-29powerpc/signal: Add unsafe_copy_{vsx, fpr}_from_user()Christopher M. Riedl1-0/+26
Reuse the "safe" implementation from signal.c but call unsafe_get_user() directly in a loop to avoid the intermediate copy into a local buffer. Signed-off-by: Christopher M. Riedl <cmr@codefail.de> Reviewed-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210227011259.11992-3-cmr@codefail.de
2021-03-26powerpc/ptrace: Convert gpr32_set_common() to user access blockChristophe Leroy1-12/+18
Use user access block in gpr32_set_common() instead of repetitive __get_user() which imply repetitive KUAP open/close. To get it clean, force inlining of the small set of tiny functions called inside the block. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bdcb8652c3bb4ab5b8b3bfd08147434be8fc04c9.1615398498.git.christophe.leroy@csgroup.eu
2021-03-26powerpc/syscalls: Use sys_old_select() in ppc_select()Christophe Leroy1-10/+2
Instead of opencodying the copy of parameters, use the generic sys_old_select(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4de983ad254739da1fe6e9f273baf387b7043ae0.1615398498.git.christophe.leroy@csgroup.eu
2021-03-24powerpc/ptrace: Remove duplicate check from pt_regs_check()Denis Efremov1-2/+0
"offsetof(struct pt_regs, msr) == offsetof(struct user_pt_regs, msr)" checked in pt_regs_check() twice in a row. Remove the second check. Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210305112807.26299-1-efremov@linux.com
2021-03-24powerpc: Remove duplicate includesZhang Yunkai2-2/+0
asm/tm.h included in traps.c is duplicated. It is also included on the 62nd line. asm/udbg.h included in setup-common.c is duplicated. It is also included on the 61st line. asm/bug.h included in arch/powerpc/include/asm/book3s/64/mmu-hash.h is duplicated. It is also included on the 12th line. asm/tlbflush.h included in arch/powerpc/include/asm/pgtable.h is duplicated. It is also included on the 11th line. asm/page.h included in arch/powerpc/include/asm/thread_info.h is duplicated. It is also included on the 13th line. Signed-off-by: Zhang Yunkai <zhang.yunkai@zte.com.cn> [mpe: Squash together from multiple commits] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2021-03-24powerpc/prom: Mark identical_pvr_fixup as __initNathan Chancellor1-1/+1
If identical_pvr_fixup() is not inlined, there are two modpost warnings: WARNING: modpost: vmlinux.o(.text+0x54e8): Section mismatch in reference from the function identical_pvr_fixup() to the function .init.text:of_get_flat_dt_prop() The function identical_pvr_fixup() references the function __init of_get_flat_dt_prop(). This is often because identical_pvr_fixup lacks a __init annotation or the annotation of of_get_flat_dt_prop is wrong. WARNING: modpost: vmlinux.o(.text+0x551c): Section mismatch in reference from the function identical_pvr_fixup() to the function .init.text:identify_cpu() The function identical_pvr_fixup() references the function __init identify_cpu(). This is often because identical_pvr_fixup lacks a __init annotation or the annotation of identify_cpu is wrong. identical_pvr_fixup() calls two functions marked as __init and is only called by a function marked as __init so it should be marked as __init as well. At the same time, remove the inline keywork as it is not necessary to inline this function. The compiler is still free to do so if it feels it is worthwhile since commit 889b3c1245de ("compiler: remove CONFIG_OPTIMIZE_INLINING entirely"). Fixes: 14b3d926a22b ("[POWERPC] 4xx: update 440EP(x)/440GR(x) identical PVR issue workaround") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/1316 Link: https://lore.kernel.org/r/20210302200829.2680663-1-nathan@kernel.org
2021-03-24powerpc/fadump: Mark fadump_calculate_reserve_size as __initNathan Chancellor1-1/+1
If fadump_calculate_reserve_size() is not inlined, there is a modpost warning: WARNING: modpost: vmlinux.o(.text+0x5196c): Section mismatch in reference from the function fadump_calculate_reserve_size() to the function .init.text:parse_crashkernel() The function fadump_calculate_reserve_size() references the function __init parse_crashkernel(). This is often because fadump_calculate_reserve_size lacks a __init annotation or the annotation of parse_crashkernel is wrong. fadump_calculate_reserve_size() calls parse_crashkernel(), which is marked as __init and fadump_calculate_reserve_size() is called from within fadump_reserve_mem(), which is also marked as __init. Mark fadump_calculate_reserve_size() as __init to fix the section mismatch. Additionally, remove the inline keyword as it is not necessary to inline this function; the compiler is still free to do so if it feels it is worthwhile since commit 889b3c1245de ("compiler: remove CONFIG_OPTIMIZE_INLINING entirely"). Fixes: 11550dc0a00b ("powerpc/fadump: reuse crashkernel parameter for fadump memory reservation") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/ClangBuiltLinux/linux/issues/1300 Link: https://lore.kernel.org/r/20210302195013.2626335-1-nathan@kernel.org
2021-03-24powerpc: Fix spelling of "droping" to "dropping" in traps.cBhaskar Chowdhury1-1/+1
s/droping/dropping/ Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210224075547.763063-1-unixbhaskar@gmail.com
2021-03-24powerpc: remove unneeded semicolonJiapeng Chong1-1/+1
Fix the following coccicheck warnings: ./arch/powerpc/kernel/prom_init.c:2986:2-3: Unneeded semicolon. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1614151761-53721-1-git-send-email-jiapeng.chong@linux.alibaba.com
2021-03-17quota: wire up quotactl_pathSascha Hauer1-0/+1
Wire up the quotactl_path syscall added in the previous patch. Link: https://lore.kernel.org/r/20210304123541.30749-3-s.hauer@pengutronix.de Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-03-14powerpc/vdso32: Add missing _restgpr_31_x to fix build failureChristophe Leroy1-0/+11
With some defconfig including CONFIG_CC_OPTIMIZE_FOR_SIZE, (for instance mvme5100_defconfig and ps3_defconfig), gcc 5 generates a call to _restgpr_31_x. Until recently it went unnoticed, but commit 42ed6d56ade2 ("powerpc/vdso: Block R_PPC_REL24 relocations") made it rise to the surface. Provide that function (copied from lib/crtsavres.S) in gettimeofday.S Fixes: ab037dd87a2f ("powerpc/vdso: Switch VDSO to generic C implementation.") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a7aa198a88bcd33c6e35e99f70f86c7b7f2f9440.1615270757.git.christophe.leroy@csgroup.eu
2021-03-12powerpc/traps: unrecoverable_exception() is not an interrupt handlerChristophe Leroy2-2/+1
unrecoverable_exception() is called from interrupt handlers or after an interrupt handler has failed. Make it a standard function to avoid doubling the actions performed on interrupt entry (e.g.: user time accounting). Fixes: 3a96570ffceb ("powerpc: convert interrupt handlers to use wrappers") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ae96c59fa2cb7f24a8929c58cfa2c909cb8ff1f1.1615291471.git.christophe.leroy@csgroup.eu
2021-03-09powerpc/64s/exception: Clean up a missed SRR specifierDaniel Axtens1-1/+1
Nick's patch cleaning up the SRR specifiers in exception-64s.S missed a single instance of EXC_HV_OR_STD. Clean that up. Caught by clang's integrated assembler. Fixes: 3f7fbd97d07d ("powerpc/64s/exception: Clean up SRR specifiers") Signed-off-by: Daniel Axtens <dja@axtens.net> Acked-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210225031006.1204774-2-dja@axtens.net
2021-03-08printk: introduce a kmsg_dump iteratorJohn Ogness1-3/+5
Rather than storing the iterator information in the registered kmsg_dumper structure, create a separate iterator structure. The kmsg_dump_iter structure can reside on the stack of the caller, thus allowing lockless use of the kmsg_dump functions. Update code that accesses the kernel logs using the kmsg_dumper structure to use the new kmsg_dump_iter structure. For kmsg_dumpers, this also means adding a call to kmsg_dump_rewind() to initialize the iterator. All this is in preparation for removal of @logbuf_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> # pstore Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-03-01powerpc/syscall: Force inlining of __prep_irq_for_enabled_exit()Christophe Leroy1-1/+1
As reported by kernel test robot, a randconfig with high amount of debuging options can lead to build failure for undefined reference to replay_soft_interrupts() on ppc32. This is due to gcc not seeing that __prep_irq_for_enabled_exit() always returns true on ppc32 because it doesn't inline it for some reason. Force inlining of __prep_irq_for_enabled_exit() to fix the build. Fixes: 344bb20b159d ("powerpc/syscall: Make interrupt.c buildable on PPC32") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/53f3a1f719441761000c41154602bf097d4350b5.1614148356.git.christophe.leroy@csgroup.eu