- 24 Dec, 2021 2 commits
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Michael Ellerman authored
When CONFIG_PPC_RFI_SRR_DEBUG=y we check the SRR values before returning from interrupts. This is done in asm using EMIT_BUG_ENTRY, and passing BUGFLAG_WARNING. However that fails to create an exception table entry for the warning, and so do_program_check() fails the exception table search and proceeds to call _exception(), resulting in an oops like: Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 2 PID: 1204 Comm: sigreturn_unali Tainted: P 5.16.0-rc2-00194-g91ca3d4f77c5 #12 NIP: c00000000000c5b0 LR: 0000000000000000 CTR: 0000000000000000 ... NIP [c00000000000c5b0] system_call_common+0x150/0x268 LR [0000000000000000] 0x0 Call Trace: [c00000000db73e10] [c00000000000c558] system_call_common+0xf8/0x268 (unreliable) ... Instruction dump: 7cc803a6 888d0931 2c240000 4082001c 38800000 988d0931 e8810170 e8a10178 7c9a03a6 7cbb03a6 7d7a02a6 e9810170 <7f0b6088> 7d7b02a6 e9810178 7f0b6088 We should instead use EMIT_WARN_ENTRY, which creates an exception table entry for the warning, allowing the warning to be correctly recognised, and the code to resume after printing the warning. Note however that because this warning is buried deep in the interrupt return path, we are not able to recover from it (due to MSR_RI being clear), so we still end up in die() with an unrecoverable exception. Fixes: 59dc5bfc ("powerpc/64s: avoid reloading (H)SRR registers if they are still valid") Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211221135101.2085547-2-mpe@ellerman.id.au
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Michael Ellerman authored
When CONFIG_PPC_RFI_SRR_DEBUG=y we check that NIP and SRR0 match when returning from interrupts. This can trigger falsely if NIP has either of its two low bits set via sigreturn or ptrace, while SRR0 has its low two bits masked in hardware. As a quick fix make sure to mask the low bits before doing the check. Fixes: 59dc5bfc ("powerpc/64s: avoid reloading (H)SRR registers if they are still valid") Reported-by:
Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by:
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- 23 Dec, 2021 38 commits
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Randy Dunlap authored
Use the possessive "its" instead of the contraction of "it is" (it's). Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Christophe Leroy authored
Boot fails with GCC latent entropy plugin enabled. This is due to early boot functions trying to access 'latent_entropy' global data while the kernel is not relocated at its final destination yet. As there is no way to tell GCC to use PTRRELOC() to access it, disable latent entropy plugin in early_32.o and feature-fixups.o and code-patching.o Fixes: 38addce8 ("gcc-plugins: Add latent_entropy plugin") Cc: stable@vger.kernel.org # v4.9+ Reported-by:
Erhard Furtner <erhard_f@mailbox.org> Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:
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Christophe Leroy authored
The purpose of selftests is to check that instructions are properly formed. Not to check that they properly run. For that test it uses normal memory, not special test memory. In preparation of a future patch enforcing patch_instruction() to be used only on valid text areas, implement a ppc_inst_write() instruction which is the complement of ppc_inst_read(). This new function writes the formated instruction in valid kernel memory and doesn't bother about icache. Signed-off-by:
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Christophe Leroy authored
Code patching selftests are half of code-patching.c. As they are guarded by CONFIG_CODE_PATCHING_SELFTESTS, they'd be better in their own file. Also add a missing __init for instr_is_branch_to_addr() Signed-off-by:
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Christophe Leroy authored
To enable moving selftests in their own C file in following patch, move instr_is_branch_iform() and instr_is_branch_bform() to code-patching.h Signed-off-by:
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Christophe Leroy authored
patch_exception() is dedicated to book3e/64 is nothing more than a normal use of patch_branch(), so move it into a place dedicated to book3e/64. Signed-off-by:
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Christophe Leroy authored
Use the dedicated test_trampoline function for testing prefixed patching like other tests and remove the hand coded assembly stuff. Signed-off-by:
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Christophe Leroy authored
Do not silentely ignore a failure of create_branch() in patch_branch(). Return -ERANGE. Signed-off-by:
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Christophe Leroy authored
Split do_patch_instruction() in two functions, the caller doing the spin locking and the callee doing everything else. And remove a few unnecessary initialisations and intermediate variables. This allows the callee to return from anywhere in the function. Signed-off-by:
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Christophe Leroy authored
pXd_offset() doesn't return NULL. When the base is NULL, it still adds the offset. Use pXd_none() to check validity instead. It also improves performance by folding out none existing levels as pXd_none() always returns 0 in that case. Such an error is unexpected, use WARN_ON() so that the caller doesn't have to worry about it, and drop the returned value. And now that unmap_patch_area() doesn't return error, we can take into account the error returned by __patch_instruction(). While at it, remove the 'inline' property which is useless. Signed-off-by:
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Christophe Leroy authored
Use real errors instead of using -1 as error, so that errors returned by callees can be used towards callers. Signed-off-by:
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Christophe Leroy authored
A new state has been added by commit d2635f20 ("mm: create a new system state and fix core_kernel_text()"). That state tells when initmem is about to be released and is redundant with init_mem_is_free. Remove init_mem_is_free. Signed-off-by:
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Christophe Leroy authored
code-patching has been working for years now, time has come to remove debugging messages. Change useful message to KERN_INFO and remove other ones. Also add KERN_ERR to check() macro and change it into a do/while to make checkpatch happy. Signed-off-by:
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Alexey Kardashevskiy authored
The llvm integrated assembler does not recognise the ISA 2.05 tlbiel version. Work around it by switching to .long when an old arch level detected. Signed-off-by:
Daniel Axtens <dja@axtens.net> [aik: did "Eventually do this more smartly"] Signed-off-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
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Alexey Kardashevskiy authored
The dssall ("Data Stream Stop All") instruction is obsolete altogether with other Data Cache Instructions since ISA 2.03 (year 2006). LLVM IAS does not support it but PPC970 seems to be using it. This switches dssall to .long as there is no much point in fixing LLVM. Signed-off-by: -
Daniel Axtens authored
The LLVM integrated assembler really does not like us reassigning things to the same label: <instantiation>:7:9: error: invalid reassignment of non-absolute variable 'fs_label' This happens across a bunch of platforms: https://github.com/ClangBuiltLinux/linux/issues/1043 https://github.com/ClangBuiltLinux/linux/issues/1008 https://github.com/ClangBuiltLinux/linux/issues/920 https://github.com/ClangBuiltLinux/linux/issues/1050 There is no hope of getting this fixed in LLVM (see https://github.com/ClangBuiltLinux/linux/issues/1043#issuecomment-641571200 and https://bugs.llvm.org/show_bug.cgi?id=47798#c1 ) so if we want to build with LLVM_IAS, we need to hack around it ourselves. For us the big problem comes from this: \#define USE_FIXED_SECTION(sname) \ fs_label = start_##sname; \ fs_start = sname##_start; \ use_ftsec sname; \#define USE_TEXT_SECTION() fs_label = start_text; \ fs_start = text_start; \ .text and in particular fs_label. This works around it by not setting those 'variables' and requiring that users of the variables instead track for themselves what section they are in. This isn't amazing, by any stretch, but it gets us further in the compilation. Note that even though users have to keep track of the section, using a wrong one produces an error with both binutils and llvm which prevents from using wrong section at the compile time: llvm error example: AS arch/powerpc/kernel/head_64.o <unknown>:0: error: Cannot represent a difference across sections make[3]: *** [/home/aik/p/kernels-llvm/llvm/scripts/Makefile.build:388: arch/powerpc/kernel/head_64.o] Error 1 binutils error example: /home/aik/p/kernels-llvm/llvm/arch/powerpc/kernel/exceptions-64s.S: Assembler messages: /home/aik/p/kernels-llvm/llvm/arch/powerpc/kernel/exceptions-64s.S:1974: Error: can't resolve `system_call_common' {.text section} - `start_r eal_vectors' {.head.text.real_vectors section} make[3]: *** [/home/aik/p/kernels-llvm/llvm/scripts/Makefile.build:388: arch/powerpc/kernel/head_64.o] Error 1 Signed-off-by:
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Alexey Kardashevskiy authored
It is used just once and does not really help with readability, remove it. Signed-off-by:
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Daniel Axtens authored
LLVM's integrated assembler does not like either -Wa,-mpower4 or -Wa,-many. So just don't pass them if they're not supported. Signed-off-by:
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Alan Modra authored
This patch future-proofs the kernel against linker changes that might put the toc pointer at some location other than .got+0x8000, by replacing __toc_start+0x8000 with .TOC. throughout. If the kernel's idea of the toc pointer doesn't agree with the linker, bad things happen. prom_init.c code relocating its toc is also changed so that a symbolic __prom_init_toc_start toc-pointer relative address is calculated rather than assuming that it is always at toc-pointer - 0x8000. The length calculations loading values from the toc are also avoided. It's a little incestuous to do that with unreloc_toc picking up adjusted values (which is fine in practice, they both adjust by the same amount if all goes well). I've also changed the way .got is aligned in vmlinux.lds and zImage.lds, mostly so that dumping out section info by objdump or readelf plainly shows the alignment is 256. This linker script feature was added 2005-09-27, available in FSF binutils releases from 2.17 onwards. Should be safe to use in the kernel, I think. Finally, put *(.got) before the prom_init.o entry which only needs *(.toc), so that the GOT header goes in the correct place. I don't believe this makes any difference for the kernel as it would for dynamic objects being loaded by ld.so. That change is just to stop lusers who blindly copy kernel scripts being led astray. Of course, this change needs the prom_init.c changes. Some notes on .toc and .got. .toc is a compiler generated section of addresses. .got is a linker generated section of addresses, generally built when the linker sees R_*_*GOT* relocations. In the case of powerpc64 ld.bfd, there are multiple generated .got sections, one per input object file. So you can somewhat reasonably write in a linker script an input section statement like *prom_init.o(.got .toc) to mean "the .got and .toc section for files matching *prom_init.o". On other architectures that doesn't make sense, because the linker generally has just one .got section. Even on powerpc64, note well that the GOT entries for prom_init.o may be merged with GOT entries from other objects. That means that if prom_init.o references, say, _end via some GOT relocation, and some other object also references _end via a GOT relocation, the GOT entry for _end may be in the range __prom_init_toc_start to __prom_init_toc_end and if the kernel does something special to GOT/TOC entries in that range then the value of _end as seen by objects other than prom_init.o will be affected. On the other hand the GOT entry for _end may not be in the range __prom_init_toc_start to __prom_init_toc_end. Which way it turns out is deterministic but a detail of linker operation that should not be relied on. A feature of ld.bfd is that input .toc (and .got) sections matching one linker input section statement may be sorted, to put entries used by small-model code first, near the toc base. This is why scripts for powerpc64 normally use *(.got .toc) rather than *(.got) *(.toc), since the first form allows more freedom to sort. Another feature of ld.bfd is that indirect addressing sequences using the GOT/TOC may be edited by the linker to relative addressing. In many cases relative addressing would be emitted by gcc for -mcmodel=medium if you appropriately decorate variable declarations with non-default visibility. The original patch is here: https://lore.kernel.org/linuxppc-dev/20210310034813.GM6042@bubble.grove.modra.org/Signed-off-by:
Alan Modra <amodra@au1.ibm.com> [aik: removed non-relocatable which is gone in 24d33ac5] [aik: added <=2.24 check] [aik: because of llvm-as, kernel_toc_addr() uses "mr" instead of global register variable] Signed-off-by:
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Nick Child authored
Make `find_via_cuda` and `find_via_pmu` initialization functions. Previously, their definitions in `drivers/macintosh/via-cuda.h` include the `__init` attribute but their alternative definitions in `arch/powerpc/powermac/sectup./c` and prototypes in `include/linux/ cuda.h` and `include/linux/pmu.h` do not use the `__init` macro. Since, only initialization functions call `find_via_cuda` and `find_via_pmu` it is safe to label these functions with `__init`. Signed-off-by:
Nick Child <nick.child@ibm.com> Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/512x' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/85xx' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/83xx' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/embedded6xx' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/44x/' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/4xx' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/ps3' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/pseries' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/powernv' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/powermac` are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/pasemi' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
The function `Enable_SRAM` defined in 'arch/powerpc/platforms/chrp' is deserving of an `__init` macro attribute. This function is only called by other initialization functions and therefore should inherit the attribute. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/platforms/cell' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Signed-off-by:
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Nick Child authored
`xmon_register_spus` defined in 'arch/powerpc/xmon' is deserving of an `__init` macro attribute. This functions is only called by other initialization functions and therefore should inherit the attribute. Also, change the function declaration in the header file to include `__init`. Signed-off-by:
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Nick Child authored
Some files functions in 'arch/powerpc/sysdev' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/perf' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/mm' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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Nick Child authored
Some functions defined in 'arch/powerpc/lib' are deserving of an `__init` macro attribute. These functions are only called by other initialization functions and therefore should inherit the attribute. Also, change function declarations in header files to include `__init`. Signed-off-by:
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