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path: root/arch/powerpc/kernel/head_booke.h
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2022-09-26powerpc: Remove CONFIG_PPC_BOOK3E_MMUChristophe Leroy
CONFIG_PPC_BOOK3E_MMU is redundant with CONFIG_PPC_E500. Remove it. Also rename mmu-book3e.h to mmu-e500.h Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c5549cd59a131204ff94ab909cad2e2dad4ddf2f.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26powerpc: Remove CONFIG_PPC_FSL_BOOK3EChristophe Leroy
CONFIG_PPC_FSL_BOOK3E is redundant with CONFIG_PPC_E500. Remove it. And rename five files accordingly. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Rename include guards to match new file names] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/795cb93b88c9a0279289712e674f39e3b108a1b4.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26powerpc: Change CONFIG_E500 to CONFIG_PPC_E500Christophe Leroy
It will be used outside arch/powerpc, make it clear its a powerpc configuration item. And we already have CONFIG_PPC_E500MC, so that will make it more consistent. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e63b22083c11c4300f4a82d3123a46e5fdd54fa6.1663606876.git.christophe.leroy@csgroup.eu
2021-11-29powerpc: flexible GPR range save/restore macrosNicholas Piggin
Introduce macros that operate on a (start, end) range of GPRs, which reduces lines of code and need to do mental arithmetic while reading the code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211022061322.2671178-1-npiggin@gmail.com
2021-10-29powerpc/32e: Ignore ESR in instruction storage interrupt handlerNicholas Piggin
A e5500 machine running a 32-bit kernel sometimes hangs at boot, seemingly going into an infinite loop of instruction storage interrupts. The ESR (Exception Syndrome Register) has a value of 0x800000 (store) when this happens, which is likely set by a previous store. An instruction TLB miss interrupt would then leave ESR unchanged, and if no PTE exists it calls directly to the instruction storage interrupt handler without changing ESR. access_error() does not cause a segfault due to a store to a read-only vma because is_exec is true. Most subsequent fault handling does not check for a write fault on a read-only vma, and might do strange things like create a writeable PTE or call page_mkwrite on a read only vma or file. It's not clear what happens here to cause the infinite faulting in this case, a fault handler failure or low level PTE or TLB handling. In any case this can be fixed by having the instruction storage interrupt zero regs->dsisr rather than storing the ESR value to it. Fixes: a01a3f2ddbcd ("powerpc: remove arguments from fault handler functions") Cc: stable@vger.kernel.org # v5.12+ Reported-by: Jacques de Laval <jacques.delaval@protonmail.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Tested-by: Jacques de Laval <jacques.delaval@protonmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211028133043.4159501-1-npiggin@gmail.com
2021-08-07powerpc/32: Fix critical and debug interrupts on BOOKEChristophe Leroy
32 bits BOOKE have special interrupts for debug and other critical events. When handling those interrupts, dedicated registers are saved in the stack frame in addition to the standard registers, leading to a shift of the pt_regs struct. Since commit db297c3b07af ("powerpc/32: Don't save thread.regs on interrupt entry"), the pt_regs struct is expected to be at the same place all the time. Instead of handling a special struct in addition to pt_regs, just add those special registers to struct pt_regs. Fixes: db297c3b07af ("powerpc/32: Don't save thread.regs on interrupt entry") Cc: stable@vger.kernel.org Reported-by: Radu Rendec <radu.rendec@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/028d5483b4851b01ea4334d0751e7f260419092b.1625637264.git.christophe.leroy@csgroup.eu
2021-06-25powerpc/32: Avoid #ifdef nested with FTR_SECTION on booke syscall entryChristophe Leroy
On booke, SYSCALL_ENTRY macro nests an FTR_SECTION with a #ifdef CONFIG_KVM_BOOKE_HV. Duplicate the single instruction alternative to avoid nesting. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/33db61d5f85146262dbe26648f8f87eca3cae393.1622818435.git.christophe.leroy@csgroup.eu
2021-06-25powerpc/32: Reduce code duplication of system call entryChristophe Leroy
booke and non booke do pretty similar things in SYSCALL_ENTRY macro just before calling jumping to transfer_to_syscall(). Do them in transfer_to_syscall() instead. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/552e27fa09394a6bc70585fcdfa237f99a5d1267.1622818435.git.christophe.leroy@csgroup.eu
2021-06-25powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on bookeChristophe Leroy
To better match non booke version of SYSCALL_ENTRY macro, interchange r1 and r11 in the booke version. While at it, in both versions use r1 instead of r11 to save _NIP and _CCR. All other uses of r11 will go away in next patch, so don't bother changing them for now. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1684c39724a069b0ce1aa82eaee6ec194e354e4e.1622818435.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32s: Move KUEP locking/unlocking in CChristophe Leroy
This can be done in C, do it. Unrolling the loop gains approx. 15% performance. From now on, prepare_transfer_to_handler() is only for interrupts from kernel. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4eadd873927e9a73c3d1dfe2f9497353465514cf.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500Christophe Leroy
Only book3s/32 and e500 have significative work to do in prepare_transfer_to_handler. Other 32 bit have nothing to do at all. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b5e29ca0e557c11340415a13fe8b107189d315e1.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Save remaining registers in exception prologChristophe Leroy
Save non volatile registers, XER, CTR, MSR and NIP in exception prolog. Also assign proper value to r2 and r3 there. For now, recalculate thread pointer in prepare_transfer_to_handler. It will disappear once KUAP is ported to C. And remove the comment which is now completely wrong. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/56f0cde9dd0362edf2ddba4d887552013eee7329.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Refactor saving of volatile registers in exception prologsChristophe Leroy
Exception prologs all do the same at the end: - Save trapno in stack - Mark stack with exception marker - Save r0 - Save r3 to r8 Refactor that into a COMMON_EXCEPTION_PROLOG_END macro. At the same time use r1 instead of r11. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e1c45d2e895e0693c42d2a6840df1105a148efea.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Remove the xfer parameter in EXCEPTION() macroChristophe Leroy
The xfer parameter is not used anymore, remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/17c7d68bd18f7d2f1ab24a1a20d9ed33bbcda741.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATEChristophe Leroy
In order to get more control in exception prolog, dismantle all non standard exception macros, finishing with EXC_XFER_STD and EXC_XFER_LITE and EXC_XFER_TEMPLATE. Also remove transfer_to_handler_full and ret_from_except and ret_from_except_full as they are not used anymore. Last parameter of EXCEPTION() is now ignored, will be removed in a later patch to avoid too much churn. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ca5795d04a220586b7037dbbbe6951dfa9e768eb.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Only restore non volatile registers when requiredChristophe Leroy
Until now, non volatile registers were restored everytime they were saved, ie using EXC_XFER_STD meant saving and restoring them while EXC_XFER_LITE meant neither saving not restoring them. Now that they are always saved, EXC_XFER_STD means to restore them and EXC_XFER_LITE means to not restore them. Most of the users of EXC_XFER_STD only need to retrieve the non volatile registers. For them there is no need to restore the non volatile registers as they have not been modified. Only very few exceptions require non volatile registers restore. Opencode the few places which require saving of non volatile registers. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d1cb12d8023cc6afc1f07150565571373c04945c.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Add a prepare_transfer_to_handler macro for exception prologsChristophe Leroy
In order to increase flexibility, add a macro that will for now call transfer_to_handler. As transfer_to_handler doesn't do the actual transfer anymore, also name it prepare_transfer_to_handler. The following patches will progressively remove the use of transfer_to_handler label. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7f757c52518ab1d7b27ad5113b10f860e803f467.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Save trap number on stack in exception prologChristophe Leroy
Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Call bad_page_fault() from do_page_fault()Christophe Leroy
Now that non volatile registers are saved at all time, no need to split bad_page_fault() out of do_page_fault(). Remove handle_page_fault() and use do_page_fault() directly. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/cfb95be8863204cc2bf45a22ea44dd1d0dc16b7f.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Set regs parameter in r3 in transfer_to_handlerChristophe Leroy
All exception handlers take regs as first parameter. Instead of setting r3 just before each call to a handler, set it in transfer_to_handler. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f994a379bb895a2cbd518cb82460ad3f3d3ccdf5.1615552867.git.christophe.leroy@csgroup.eu
2021-03-29powerpc/32: Always save non volatile registers on exception entryChristophe Leroy
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 Leroy
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 Leroy
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: Enable instruction translation at the same time as data translationChristophe Leroy
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: Remove ksp_limitChristophe Leroy
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
2021-02-11powerpc/32: Handle bookE debugging in C in syscall entry/exitChristophe Leroy
The handling of SPRN_DBCR0 and other registers can easily be done in C instead of ASM. For that, create booke_load_dbcr0() and booke_restore_dbcr0(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1a7515f9258b27a9177de88491a8bb79b255ceb7.1612898425.git.christophe.leroy@csgroup.eu
2021-02-11powerpc/32: Remove the counter in global_dbcr0Christophe Leroy
global_dbcr0 has two parts, 4 bytes to save/restore the value of SPRN_DBCR0, and 4 bytes that are incremented/decremented everytime something is saving/loading the above value. This counter is only incremented/decremented, its value is never used and never read. Remove the counter and devide the size of global_dbcr0 by 2. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7e381dc58b3f583556cfab37ba5d813bfd5cce1e.1612796617.git.christophe.leroy@csgroup.eu
2021-02-11powerpc/32: Remove verification of MSR_PR on syscall in the ASM entryChristophe Leroy
system_call_exception() checks MSR_PR and BUGs if a syscall is issued from kernel mode. No need to handle it anymore from the ASM entry code. null_syscall reduction 2 cycles (348 => 346 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/1eddb42cb12092b1e3d72608d182c365db3da41d.1612796617.git.christophe.leroy@csgroup.eu
2021-02-11powerpc/syscall: implement system call entry/exit logic in C for PPC32Christophe Leroy
That's port of PPC64 syscall entry/exit logic in C to PPC32. Performancewise on 8xx: Before : 304 cycles on null_syscall After : 348 cycles on null_syscall Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a93b08e1275e9d1f0b1c39043d1b827586b2b401.1612796617.git.christophe.leroy@csgroup.eu
2021-02-11powerpc/32: Always save non volatile GPRs at syscall entryChristophe Leroy
In preparation for porting syscall entry/exit to C, inconditionally save non volatile general purpose registers. Commit 965dd3ad3076 ("powerpc/64/syscall: Remove non-volatile GPR save optimisation") provides detailed explanation. This increases the number of cycles by 24 cycles on 8xx with null_syscall benchmark (280 => 304 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/21c08162b83655195fe9ead78ff2cfd28508d023.1612796617.git.christophe.leroy@csgroup.eu
2021-02-11powerpc/32: On syscall entry, enable instruction translation at the same ↵Christophe Leroy
time as data 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. 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. This reduces null_syscall benchmark by 13 cycles on 8xx (296 ==> 283 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/3fe8891c814103a3549efc1d4e7ffc828bba5993.1612796617.git.christophe.leroy@csgroup.eu
2021-02-11powerpc/32: Always enable data translation on syscall entryChristophe Leroy
If the code can use a stack in vm area, it can also use a stack in linear space. Simplify code by removing old non VMAP stack code on PPC32 in syscall. That means the data translation is now re-enabled early in syscall entry in all cases, not only when using VMAP stacks. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/412c6c1786922d991bbb89c2ad2e82cffe8ab112.1612796617.git.christophe.leroy@csgroup.eu
2021-02-09powerpc: DebugException remove argsNicholas Piggin
Like other interrupt handler conversions, switch to getting registers from the pt_regs argument. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-10-npiggin@gmail.com
2021-02-09powerpc: remove arguments from fault handler functionsNicholas Piggin
Make mm fault handlers all just take the pt_regs * argument and load DAR/DSISR from that. Make those that return a value return long. This is done to make the function signatures match other handlers, which will help with a future patch to add wrappers. Explicit arguments could be added for performance but that would require more wrapper macro variants. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-7-npiggin@gmail.com
2020-12-05powerpc: Retire e200 core (mpc555x processor)Christophe Leroy
There is no defconfig selecting CONFIG_E200, and no platform. e200 is an earlier version of booke, a predecessor of e500, with some particularities like an unified cache instead of both an instruction cache and a data cache. Remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Scott Wood <oss@buserror.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/34ebc3ba2c768d97f363bd5f2deea2356e9ae127.1605589460.git.christophe.leroy@csgroup.eu
2020-11-19powerpc: Replace RFI by rfi on book3s/32 and bookeChristophe Leroy
For book3s/32 and for booke, RFI is just an rfi. Only 40x has a non trivial RFI. CONFIG_PPC_RTAS is never selected by 40x platforms. Make it more explicit by replacing RFI by rfi wherever possible. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b901ddfdeb8a0a3b7cb59999599cdfde1bbfe834.1604854583.git.christophe.leroy@csgroup.eu
2020-10-08powerpc: Remove SYNC on non 6xxChristophe Leroy
SYNC is usefull for Powerpc 601 only. On everything else, SYNC is empty. Remove it from code that is not made to run on 6xx. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/27951fa6c9a8f80724d1bc81a6117ac32343a55d.1601362098.git.christophe.leroy@csgroup.eu
2020-05-11powerpc: Replace _ALIGN_UP() by ALIGN()Christophe Leroy
_ALIGN_UP() is specific to powerpc ALIGN() is generic and does the same Replace _ALIGN_UP() by ALIGN() Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Joel Stanley <joel@jms.id.au> Link: https://lore.kernel.org/r/8a6d7e45f7904c73a0af539642d3962e2a3c7268.1587407777.git.christophe.leroy@c-s.fr
2020-02-19powerpc/32: Warn and return ENOSYS on syscalls from kernelChristophe Leroy
Since commit b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE") and commit 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE"), syscalls from kernel are unexpected and can have catastrophic consequences as it will destroy the kernel stack. Test MSR_PR on syscall entry. In case syscall is from kernel, emit a warning and return ENOSYS error. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
2020-01-26powerpc/32: save DEAR/DAR before calling handle_page_faultChristophe Leroy
handle_page_fault() is the only function that save DAR/DEAR itself. Save DAR/DEAR before calling handle_page_fault() to prepare for VMAP stack which will require to save even before. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3a4d58d378091086f00fde42b59610c80289e120.1576916812.git.christophe.leroy@c-s.fr
2019-06-16powerpc/32: fix build failure on book3e with KVMChristophe Leroy
Build failure was introduced by the commit identified below, due to missed macro expension leading to wrong called function's name. arch/powerpc/kernel/head_fsl_booke.o: In function `SystemCall': arch/powerpc/kernel/head_fsl_booke.S:416: undefined reference to `kvmppc_handler_BOOKE_INTERRUPT_SYSCALL_SPRN_SRR1' Makefile:1052: recipe for target 'vmlinux' failed The called function should be kvmppc_handler_8_0x01B(). This patch fixes it. Reported-by: Paul Mackerras <paulus@ozlabs.org> Fixes: 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-15powerpc/booke: fix fast syscall entry on SMPChristophe Leroy
Use r10 instead of r9 to calculate CPU offset as r9 contains the value from SRR1 which is used later. Fixes: 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: implement fast entry for syscalls on BOOKEChristophe Leroy
This patch implements a fast entry for syscalls. Syscalls don't have to preserve non volatile registers except LR. This patch then implement a fast entry for syscalls, where volatile registers get clobbered. As this entry is dedicated to syscall it always sets MSR_EE and warns in case MSR_EE was previously off It also assumes that the call is always from user, system calls are unexpected from kernel. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: get rid of COPY_EE in exception entryChristophe Leroy
EXC_XFER_TEMPLATE() is not called with COPY_EE anymore so we can get rid of copyee parameters and related COPY_EE and NOCOPY macros. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: Enter exceptions with MSR_EE unsetChristophe Leroy
All exceptions handlers know when to reenable interrupts, so it is safer to enter all of them with MSR_EE unset, except for syscalls. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03powerpc/32: enter syscall with MSR_EE inconditionaly setChristophe Leroy
syscalls are expected to be entered with MSR_EE set. Lets make it inconditional by forcing MSR_EE on syscalls. This patch adds EXC_XFER_SYS for that. Suggested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [splited out from benh RFC patch] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc: Activate CONFIG_THREAD_INFO_IN_TASKChristophe Leroy
This patch activates CONFIG_THREAD_INFO_IN_TASK which moves the thread_info into task_struct. Moving thread_info into task_struct has the following advantages: - It protects thread_info from corruption in the case of stack overflows. - Its address is harder to determine if stack addresses are leaked, making a number of attacks more difficult. This has the following consequences: - thread_info is now located at the beginning of task_struct. - The 'cpu' field is now in task_struct, and only exists when CONFIG_SMP is active. - thread_info doesn't have anymore the 'task' field. This patch: - Removes all recopy of thread_info struct when the stack changes. - Changes the CURRENT_THREAD_INFO() macro to point to current. - Selects CONFIG_THREAD_INFO_IN_TASK. - Modifies raw_smp_processor_id() to get ->cpu from current without including linux/sched.h to avoid circular inclusion and without including asm/asm-offsets.h to avoid symbol names duplication between ASM constants and C constants. - Modifies klp_init_thread_info() to take a task_struct pointer argument. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Add task_stack.h to livepatch.h to fix build fails] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-23powerpc: Rename THREAD_INFO to TASK_STACKChristophe Leroy
This patch renames THREAD_INFO to TASK_STACK, because it is in fact the offset of the pointer to the stack in task_struct so this pointer will not be impacted by the move of THREAD_INFO. Also make it available on 64-bit, as we'll need it there when we activate THREAD_INFO_IN_TASK. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Make available on 64-bit] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-30powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'Diana Craciun
Fixed the following build warning: powerpc-linux-gnu-ld: warning: orphan section `__btb_flush_fixup' from `arch/powerpc/kernel/head_44x.o' being placed in section `__btb_flush_fixup'. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-20powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)Diana Craciun
In order to protect against speculation attacks on indirect branches, the branch predictor is flushed at kernel entry to protect for the following situations: - userspace process attacking another userspace process - userspace process attacking the kernel Basically when the privillege level change (i.e.the kernel is entered), the branch predictor state is flushed. Signed-off-by: Diana Craciun <diana.craciun@nxp.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>