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path: root/arch/powerpc/kernel/trace/ftrace.c
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2023-04-20powerpc/64: vmlinux support building with PCREL addresingNicholas Piggin
PC-Relative or PCREL addressing is an extension to the ELF ABI which uses Power ISA v3.1 PC-relative instructions to calculate addresses, rather than the traditional TOC scheme. Add an option to build vmlinux using pcrel addressing. Modules continue to use TOC addressing. - TOC address helpers and r2 are poisoned with -1 when running vmlinux. r2 could be used for something useful once things are ironed out. - Assembly must call C functions with @notoc annotation, or the linker complains aobut a missing nop after the call. This is done with the CFUNC macro introduced earlier. - Boot: with the exception of prom_init, the execution branches to the kernel virtual address early in boot, before any addresses are generated, which ensures 34-bit pcrel addressing does not miss the high PAGE_OFFSET bits. TOC relative addressing has a similar requirement. prom_init does not go to the virtual address and its addresses should not carry over to the post-prom kernel. - Ftrace trampolines are converted from TOC addressing to pcrel addressing, including module ftrace trampolines that currently use the kernel TOC to find ftrace target functions. - BPF function prologue and function calling generation are converted from TOC to pcrel. - copypage_64.S has an interesting problem, prefixed instructions have alignment restrictions so the linker can add padding, which makes the assembler treat the difference between two local labels as non-constant even if alignment is arranged so padding is not required. This may need toolchain help to solve nicely, for now move the prefix instruction out of the alternate patch section to work around it. This reduces kernel text size by about 6%. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230408021752.862660-6-npiggin@gmail.com
2023-04-20powerpc/64: Add support to build with prefixed instructionsNicholas Piggin
Add an option to build kernel and module with prefixed instructions if the CPU and toolchain support it. This is not related to kernel support for userspace execution of prefixed instructions. Building with prefixed instructions breaks some extended inline asm memory addressing, for example it will provide immediates that exceed the range of simple load/store displacement. Whether this is a toolchain or a kernel asm problem remains to be seen. For now, these are replaced with simpler and less efficient direct register addressing when compiling with prefixed. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com
2022-08-10powerpc64/ftrace: Fix ftrace for clang buildsNaveen N. Rao
Clang doesn't support -mprofile-kernel ABI, so guard the checks against CONFIG_DYNAMIC_FTRACE_WITH_REGS, rather than the elf ABI version. Fixes: 23b44fc248f4 ("powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64") Cc: stable@vger.kernel.org # v5.19+ Reported-by: Nick Desaulniers <ndesaulniers@google.com> Reported-by: Ondrej Mosnacek <omosnacek@gmail.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Tested-by: Ondrej Mosnacek <omosnacek@gmail.com> Acked-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://github.com/llvm/llvm-project/issues/57031 Link: https://github.com/ClangBuiltLinux/linux/issues/1682 Link: https://lore.kernel.org/r/20220809095907.418764-1-naveen.n.rao@linux.vnet.ibm.com
2022-07-25powerpc: Fix all occurences of duplicate wordsMichael Ellerman
Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"") fixed "the the", there's now a steady stream of patches fixing other duplicate words. Just fix them all at once, to save the overhead of dealing with individual patches for each case. This leaves a few cases of "that that", which in some contexts is correct. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220718095158.326606-1-mpe@ellerman.id.au
2022-06-29powerpc/64: Drop ppc_inst_as_str()Michael Ellerman
The ppc_inst_as_str() macro tries to make printing variable length, aka "prefixed", instructions convenient. It mostly succeeds, but it does hide an on-stack buffer, which triggers stack protector. More problematically it doesn't compile at all with GCC 12, with -Wdangling-pointer, due to the fact that it returns the char buffer declared inside the macro: arch/powerpc/kernel/trace/ftrace.c: In function '__ftrace_modify_call': ./include/linux/printk.h:475:44: error: using a dangling pointer to '__str' [-Werror=dangling-pointer=] 475 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) ... arch/powerpc/kernel/trace/ftrace.c:567:17: note: in expansion of macro 'pr_err' 567 | pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op)); | ^~~~~~ ./arch/powerpc/include/asm/inst.h:156:14: note: '__str' declared here 156 | char __str[PPC_INST_STR_LEN]; \ | ^~~~~ This could be fixed by having the caller declare the buffer, but in some places there'd need to be two buffers. In all cases where ppc_inst_as_str() is used the output is not really meant for user consumption, it's almost always indicative of a kernel bug. A simpler solution is to just print the value as an unsigned long. For normal instructions the output is identical. For prefixed instructions the value is printed as a single 64-bit quantity, whereas previously the low half was printed first. But that is good enough for debug output, especially as prefixed instructions will be rare in kernel code in practice. Old: c000000000111170 60420000 ori r2,r2,0 c000000000111174 04100001 e580fb00 .long 0xe580fb0004100001 New: c00000000010f90c 60420000 ori r2,r2,0 c00000000010f910 e580fb0004100001 .long 0xe580fb0004100001 Reported-by: Bagas Sanjaya <bagasdotme@gmail.com> Reported-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20220531065936.3674348-1-mpe@ellerman.id.au
2022-05-22powerpc/ftrace: Remove ftrace init tramp once kernel init is completeNaveen N. Rao
Stop using the ftrace trampoline for init section once kernel init is complete. Fixes: 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220516071422.463738-1-naveen.n.rao@linux.vnet.ibm.com
2022-05-22powerpc/ftrace: Minimise number of #ifdefsChristophe Leroy
A lot of #ifdefs can be replaced by IS_ENABLED() Do so. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fold in changes suggested by Naveen and Christophe on list] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/18ce6708d6f8c71d87436f9c6019f04df4125128.1652074503.git.christophe.leroy@csgroup.eu
2022-05-22powerpc/ftrace: Simplify expected_nop_sequence()Christophe Leroy
Avoid ifdefs around expected_nop_sequence(). While at it make it a bool. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/305d22472f1f92127fba09692df6bb5d079a8cd0.1652074503.git.christophe.leroy@csgroup.eu
2022-05-22powerpc/ftrace: Use size macro instead of opencodingChristophe Leroy
0x80000000 is SZ_2G. Use it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fix comparison against unsigned -SZ_2G] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bb6626e884acffe87b58736291df57db3deaa9b9.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.Christophe Leroy
PPC_RAW_xxx() macros are self explanatory and less error prone than open coding. Use them in ftrace.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9292094c9a69cef6d29ee83f435a557b59c45065.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Use BRANCH_SET_LINK instead of value 1Christophe Leroy
To make it explicit, use BRANCH_SET_LINK instead of value 1 when calling create_branch(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d57847063ac93660a5af620d4df1847f10edf61a.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Remove ftrace_plt_tramps[]Christophe Leroy
ftrace_plt_tramps table is never filled so it is useless. 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/daeeb618a6619e3a7e3f82f1bd83ca7c25af6330.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Use CONFIG_FUNCTION_TRACER instead of CONFIG_DYNAMIC_FTRACEChristophe Leroy
Since commit 0c0c52306f47 ("powerpc: Only support DYNAMIC_FTRACE not static"), CONFIG_DYNAMIC_FTRACE is always selected when CONFIG_FUNCTION_TRACER is selected. To avoid confusion and have the reader wonder what's happen when CONFIG_FUNCTION_TRACER is selected and CONFIG_DYNAMIC_FTRACE is not, use CONFIG_FUNCTION_TRACER in ifdefs instead of CONFIG_DYNAMIC_FTRACE. As CONFIG_FUNCTION_GRAPH_TRACER depends on CONFIG_FUNCTION_TRACER, ftrace.o doesn't need to appear for both symbols in Makefile. Then as ftrace.o is built only when CONFIG_FUNCTION_TRACER is selected ifdef CONFIG_FUNCTION_TRACER is not needed in ftrace.c, and since it implies CONFIG_DYNAMIC_FTRACE, CONFIG_DYNAMIC_FTRACE is not needed in ftrace.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/628d357503eb90b4a034f99b7df516caaff4d279.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64Christophe Leroy
Since c93d4f6ecf4b ("powerpc/ftrace: Add module_trampoline_target() for PPC32"), __ftrace_make_nop() for PPC32 is very similar to the one for PPC64. Same for __ftrace_make_call(). Make them common. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/96f53c237316dab4b1b8c682685266faa92da816.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2}Christophe Leroy
Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ba13d59e8c50bc9aa6328f1c7f0c0d0278e0a3a7.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Use patch_instruction() return directlyChristophe Leroy
Instead of returning -EPERM when patch_instruction() fails, just return what patch_instruction returns. That simplifies ftrace_modify_code(): 0: 94 21 ff c0 stwu r1,-64(r1) 4: 93 e1 00 3c stw r31,60(r1) 8: 7c 7f 1b 79 mr. r31,r3 c: 40 80 00 30 bge 3c <ftrace_modify_code+0x3c> 10: 93 c1 00 38 stw r30,56(r1) 14: 7c 9e 23 78 mr r30,r4 18: 7c a4 2b 78 mr r4,r5 1c: 80 bf 00 00 lwz r5,0(r31) 20: 7c 1e 28 40 cmplw r30,r5 24: 40 82 00 34 bne 58 <ftrace_modify_code+0x58> 28: 83 c1 00 38 lwz r30,56(r1) 2c: 7f e3 fb 78 mr r3,r31 30: 83 e1 00 3c lwz r31,60(r1) 34: 38 21 00 40 addi r1,r1,64 38: 48 00 00 00 b 38 <ftrace_modify_code+0x38> 38: R_PPC_REL24 patch_instruction Before: 0: 94 21 ff c0 stwu r1,-64(r1) 4: 93 e1 00 3c stw r31,60(r1) 8: 7c 7f 1b 79 mr. r31,r3 c: 40 80 00 4c bge 58 <ftrace_modify_code+0x58> 10: 93 c1 00 38 stw r30,56(r1) 14: 7c 9e 23 78 mr r30,r4 18: 7c a4 2b 78 mr r4,r5 1c: 80 bf 00 00 lwz r5,0(r31) 20: 7c 08 02 a6 mflr r0 24: 90 01 00 44 stw r0,68(r1) 28: 7c 1e 28 40 cmplw r30,r5 2c: 40 82 00 48 bne 74 <ftrace_modify_code+0x74> 30: 7f e3 fb 78 mr r3,r31 34: 48 00 00 01 bl 34 <ftrace_modify_code+0x34> 34: R_PPC_REL24 patch_instruction 38: 80 01 00 44 lwz r0,68(r1) 3c: 20 63 00 00 subfic r3,r3,0 40: 83 c1 00 38 lwz r30,56(r1) 44: 7c 63 19 10 subfe r3,r3,r3 48: 7c 08 03 a6 mtlr r0 4c: 83 e1 00 3c lwz r31,60(r1) 50: 38 21 00 40 addi r1,r1,64 54: 4e 80 00 20 blr It improves ftrace activation/deactivation duration by about 3%. Modify patch_instruction() return on failure to -EPERM in order to match with ftrace expectations. Other users of patch_instruction() do not care about the exact error value returned. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/49a8597230713e2633e7d9d7b56140787c4a7e20.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Inline ftrace_modify_code()Christophe Leroy
Inlining ftrace_modify_code(), it increases a bit the size of ftrace code but brings 5% improvment on ftrace activation. Usually in C files we let gcc decide what to do but here it really help to 'help' gcc to decide to inline, thought we don't want to force it with an __always_inline that would be too much for CONFIG_CC_OPTIMIZE_FOR_SIZE. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1597a06d57cfc80e6853838c4066e799bf6c7977.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Use is_offset_in_branch_range()Christophe Leroy
Use is_offset_in_branch_range() instead of create_branch() to check if a target is within branch range. This patch together with the previous one improves ftrace activation time by 7% Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/912ae51782f5a53c44e435497c8c3fb5cc632387.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Remove redundant create_branch() callsChristophe Leroy
Since commit d5937db114e4 ("powerpc/code-patching: Fix patch_branch() return on out-of-range failure") patch_branch() fails with -ERANGE when trying to branch out of range. No need to perform the test twice. Remove redundant create_branch() calls. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/aa45fbad0b4b7493080835d8276c0cb4ce146503.1652074503.git.christophe.leroy@csgroup.eu
2022-05-19powerpc/ftrace: Refactor prepare_ftrace_return()Christophe Leroy
When we have CONFIG_DYNAMIC_FTRACE_WITH_ARGS, prepare_ftrace_return() is called by ftrace_graph_func() otherwise prepare_ftrace_return() is called from assembly. Refactor prepare_ftrace_return() into a static __prepare_ftrace_return() that will be called by both prepare_ftrace_return() and ftrace_graph_func(). It will allow GCC to fold __prepare_ftrace_return() inside ftrace_graph_func(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0d42deafe353980c66cf19d3132638c05ba9f4a9.1652074503.git.christophe.leroy@csgroup.eu
2022-03-08powerpc: Move C prototypes out of asm-prototypes.hChristophe Leroy
We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc: Introduce asm-prototypes.h"). It's purpose was for prototypes of C functions that are only called from asm, in order to fix sparse warnings about missing prototypes. A few months later Nick added a different use case in commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm") for C prototypes for exported asm functions. This is basically the inverse of our original usage. Since then we've added various prototypes to asm-prototypes.h for both reasons, meaning we now need to unstitch it all. Dispatch prototypes of C functions into relevant headers and keep only the prototypes for functions defined in assembly. For the time being, leave prom_init() there because moving it into asm/prom.h or asm/setup.h conflicts with drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o This will be fixed later by untaggling asm/pci.h and asm/prom.h or by renaming the function in shadowrom.c Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu
2022-02-16powerpc/ftrace: Add recursion protection in prepare_ftrace_return()Christophe Leroy
The function_graph_enter() does not provide any recursion protection. Add a protection in prepare_ftrace_return() in case function_graph_enter() calls something that gets function graph traced. Fixes: 830213786c49 ("powerpc/ftrace: directly call of function graph tracer by ftrace caller") Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.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/74edf2ff0a60e66b0d9225a137100a86a0557032.1644949750.git.christophe.leroy@csgroup.eu
2022-02-07powerpc/ftrace: directly call of function graph tracer by ftrace callerChristophe Leroy
Modify function graph tracer to be handled directly by the standard ftrace caller. This is made possible as powerpc now supports CONFIG_DYNAMIC_FTRACE_WITH_ARGS. This change simplifies the call of function graph ftrace. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/04d196585ff81bde06a000bd9c633a33a5b21130.1640017960.git.christophe.leroy@csgroup.eu
2022-02-07powerpc/ftrace: Refactor ftrace_{en/dis}able_ftrace_graph_callerChristophe Leroy
ftrace_enable_ftrace_graph_caller() and ftrace_disable_ftrace_graph_caller() have common code. They will have even more common code after following patch. Refactor into a single ftrace_modify_ftrace_graph_caller() 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/f37785a531f1a8f201e1b3da45997a5c77e9d820.1640017960.git.christophe.leroy@csgroup.eu
2021-12-09powerpc/inst: Define ppc_inst_tChristophe Leroy
In order to stop using 'struct ppc_inst' on PPC32, define a ppc_inst_t typedef. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fe5baa2c66fea9db05a8b300b3e8d2880a42596c.1638208156.git.christophe.leroy@csgroup.eu
2021-11-29powerpc/ftrace: Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on PPC32Christophe Leroy
Unlike PPC64, PPC32 doesn't require any special compiler option to get _mcount() call not clobbering registers. Provide ftrace_regs_caller() and ftrace_regs_call() and activate HAVE_DYNAMIC_FTRACE_WITH_REGS. That's heavily copied from ftrace_64_mprofile.S For the time being leave livepatching aside, it will come with following patch. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1862dc7719855cc2a4eec80920d94c955877557e.1635423081.git.christophe.leroy@csgroup.eu
2021-11-29powerpc/ftrace: Add module_trampoline_target() for PPC32Christophe Leroy
module_trampoline_target() is used by __ftrace_modify_call(). Implement it for PPC32 so that CONFIG_DYNAMIC_FTRACE_WITH_REGS can be activated on PPC32 as well. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/42345f464fb465f0fc76f3090e250be8fc1729f0.1635423081.git.christophe.leroy@csgroup.eu
2021-06-17powerpc: Don't use 'struct ppc_inst' to reference instruction locationChristophe Leroy
'struct ppc_inst' is an internal representation of an instruction, but in-memory instructions are and will remain a table of 'u32' forever. Replace all 'struct ppc_inst *' used for locating an instruction in memory by 'u32 *'. This removes a lot of undue casts to 'struct ppc_inst *'. It also helps locating ab-use of 'struct ppc_inst' dereference. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fix ppc_inst_next(), use u32 instead of unsigned int] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/ftrace: Use PPC_RAW_MFLR() and PPC_RAW_NOP()Christophe Leroy
Use PPC_RAW_MFLR() instead of open coding with PPC_INST_MFLR. Same for PPC_INST_NOP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/98fd4d717810b7c4032a1edf62dd6fe638e64329.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16powerpc/lib/code-patching: Use PPC_RAW_() macrosChristophe Leroy
Instead of open coding with PPC_INST_ defines, use PPC_RAW_() macros. It improves readability. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8c92f1d9e825ee47c6f88fe43ad42d2a8cc2ab4a.1621506159.git.christophe.leroy@csgroup.eu
2021-04-21powerpc: Rename probe_kernel_read_inst()Christophe Leroy
When probe_kernel_read_inst() was created, it was to mimic probe_kernel_read() function. Since then, probe_kernel_read() has been renamed copy_from_kernel_nofault(). Rename probe_kernel_read_inst() into copy_inst_from_kernel_nofault(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b783d1f7cdb8914992384a669a2af57051b6bdcf.1618405715.git.christophe.leroy@csgroup.eu
2020-07-23powerpc: Add a ppc_inst_as_str() helperJordan Niethe
There are quite a few places where instructions are printed, this is done using a '%x' format specifier. With the introduction of prefixed instructions, this does not work well. Currently in these places, ppc_inst_val() is used for the value for %x so only the first word of prefixed instructions are printed. When the instructions are word instructions, only a single word should be printed. For prefixed instructions both the prefix and suffix should be printed. To accommodate both of these situations, instead of a '%x' specifier use '%s' and introduce a helper, __ppc_inst_as_str() which returns a char *. The char * __ppc_inst_as_str() returns is buffer that is passed to it by the caller. It is cumbersome to require every caller of __ppc_inst_as_str() to now declare a buffer. To make it more convenient to use __ppc_inst_as_str(), wrap it in a macro that uses a compound statement to allocate a buffer on the caller's stack before calling it. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> [mpe: Drop 0x prefix to match most existings uses, especially xmon] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200602052728.18227-1-jniethe5@gmail.com
2020-06-17maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofaultChristoph Hellwig
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-19powerpc: Add a probe_kernel_read_inst() functionJordan Niethe
Introduce a probe_kernel_read_inst() function to use in cases where probe_kernel_read() is used for getting an instruction. This will be more useful for prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Alistair Popple <alistair@popple.id.au> [mpe: Don't write to *inst on error] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-15-jniethe5@gmail.com
2020-05-19powerpc: Use a function for reading instructionsJordan Niethe
Prefixed instructions will mean there are instructions of different length. As a result dereferencing a pointer to an instruction will not necessarily give the desired result. Introduce a function for reading instructions from memory into the instruction data type. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-13-jniethe5@gmail.com
2020-05-19powerpc: Use a datatype for instructionsJordan Niethe
Currently unsigned ints are used to represent instructions on powerpc. This has worked well as instructions have always been 4 byte words. However, ISA v3.1 introduces some changes to instructions that mean this scheme will no longer work as well. This change is Prefixed Instructions. A prefixed instruction is made up of a word prefix followed by a word suffix to make an 8 byte double word instruction. No matter the endianness of the system the prefix always comes first. Prefixed instructions are only planned for powerpc64. Introduce a ppc_inst type to represent both prefixed and word instructions on powerpc64 while keeping it possible to exclusively have word instructions on powerpc32. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Fix compile error in emulate_spe()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
2020-05-19powerpc: Introduce functions for instruction equalityJordan Niethe
In preparation for an instruction data type that can not be directly used with the '==' operator use functions for checking equality. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Balamuruhan S <bala24@linux.ibm.com> Link: https://lore.kernel.org/r/20200506034050.24806-11-jniethe5@gmail.com
2020-05-19powerpc: Use an accessor for instructionsJordan Niethe
In preparation for introducing a more complicated instruction type to accommodate prefixed instructions use an accessor for getting an instruction as a u32. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-8-jniethe5@gmail.com
2020-05-19powerpc: Use a macro for creating instructions from u32sJordan Niethe
In preparation for instructions having a more complex data type start using a macro, ppc_inst(), for making an instruction out of a u32. A macro is used so that instructions can be used as initializer elements. Currently this does nothing, but it will allow for creating a data type that can represent prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Change include guard to _ASM_POWERPC_INST_H] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-7-jniethe5@gmail.com
2020-05-19powerpc: Change calling convention for create_branch() et. al.Jordan Niethe
create_branch(), create_cond_branch() and translate_branch() return the instruction that they create, or return 0 to signal an error. Separate these concerns in preparation for an instruction type that is not just an unsigned int. Fill the created instruction to a pointer passed as the first parameter to the function and use a non-zero return value to signify an error. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-6-jniethe5@gmail.com
2019-09-18powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTRNaveen N. Rao
This associates entries in the ftrace_ret_stack with corresponding stack frames, enabling more robust stack unwinding. Also update the only user of ftrace_graph_ret_addr() to pass the stack pointer. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/0224f2d0971b069c678e2ff678cfc2cd1e114cfe.1567707399.git.naveen.n.rao@linux.vnet.ibm.com
2019-07-06powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.hChristophe Leroy
PPC_HA() PPC_HI() and PPC_LO() macros are nice macros. Move them from module64.c to ppc-opcode.h in order to use them in other places. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Clean up formatting in new code, drop duplicates in ftrace.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-01-15powerpc/syscalls: Fix syscall tracingMichael Ellerman
Recently in commit fbf508da7440 ("powerpc: split compat syscall table out from native table") we changed the layout of the system call table. Instead of having two entries for each syscall number, one for the regular entry point and one for the compat entry point, we now have separate tables for regular and compat entry points. This inadvertently broke syscall tracing (CONFIG_FTRACE_SYSCALLS), because our implementation of arch_syscall_addr() knew about the layout of the table (it did nr * 2). We can fix it just by dropping our version of arch_syscall_addr() and using the generic version which does: return (unsigned long)sys_call_table[nr]; Fixes: fbf508da7440 ("powerpc: split compat syscall table out from native table") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-12-27Merge tag 'powerpc-4.21-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - Mitigations for Spectre v2 on some Freescale (NXP) CPUs. - A large series adding support for pass-through of Nvidia V100 GPUs to guests on Power9. - Another large series to enable hardware assistance for TLB table walk on MPC8xx CPUs. - Some preparatory changes to our DMA code, to make way for further cleanups from Christoph. - Several fixes for our Transactional Memory handling discovered by fuzzing the signal return path. - Support for generating our system call table(s) from a text file like other architectures. - A fix to our page fault handler so that instead of generating a WARN_ON_ONCE, user accesses of kernel addresses instead print a ratelimited and appropriately scary warning. - A cosmetic change to make our unhandled page fault messages more similar to other arches and also more compact and informative. - Freescale updates from Scott: "Highlights include elimination of legacy clock bindings use from dts files, an 83xx watchdog handler, fixes to old dts interrupt errors, and some minor cleanup." And many clean-ups, reworks and minor fixes etc. Thanks to: Alexandre Belloni, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Arnd Bergmann, Benjamin Herrenschmidt, Breno Leitao, Christian Lamparter, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Darren Stevens, David Gibson, Diana Craciun, Dmitry V. Levin, Firoz Khan, Geert Uytterhoeven, Greg Kurz, Gustavo Romero, Hari Bathini, Joel Stanley, Kees Cook, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Mathieu Malaterre, Michal Suchánek, Naveen N. Rao, Nick Desaulniers, Oliver O'Halloran, Paul Mackerras, Ram Pai, Ravi Bangoria, Rob Herring, Russell Currey, Sabyasachi Gupta, Sam Bobroff, Satheesh Rajendran, Scott Wood, Segher Boessenkool, Stephen Rothwell, Tang Yuantian, Thiago Jung Bauermann, Yangtao Li, Yuantian Tang, Yue Haibing" * tag 'powerpc-4.21-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (201 commits) Revert "powerpc/fsl_pci: simplify fsl_pci_dma_set_mask" powerpc/zImage: Also check for stdout-path powerpc: Fix HMIs on big-endian with CONFIG_RELOCATABLE=y macintosh: Use of_node_name_{eq, prefix} for node name comparisons ide: Use of_node_name_eq for node name comparisons powerpc: Use of_node_name_eq for node name comparisons powerpc/pseries/pmem: Convert to %pOFn instead of device_node.name powerpc/mm: Remove very old comment in hash-4k.h powerpc/pseries: Fix node leak in update_lmb_associativity_index() powerpc/configs/85xx: Enable CONFIG_DEBUG_KERNEL powerpc/dts/fsl: Fix dtc-flagged interrupt errors clk: qoriq: add more compatibles strings powerpc/fsl: Use new clockgen binding powerpc/83xx: handle machine check caused by watchdog timer powerpc/fsl-rio: fix spelling mistake "reserverd" -> "reserved" powerpc/fsl_pci: simplify fsl_pci_dma_set_mask arch/powerpc/fsl_rmu: Use dma_zalloc_coherent vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver vfio_pci: Allow regions to add own capabilities vfio_pci: Allow mapping extra regions ...
2018-11-27powerpc/function_graph: Simplify with function_graph_enter()Steven Rostedt (VMware)
The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have powerpc use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-25powerpc64/ftrace: Drop pointless static qualifier in is_b_op()YueHaibing
There is no need to have the 'intoffset' variable static since new value always be assigned before use it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-10-20powerpc/ftrace: Handle large kernel configsNaveen N. Rao
Currently, we expect to be able to reach ftrace_caller() from all ftrace-enabled functions through a single relative branch. With large kernel configs, we see functions outside of 32MB of ftrace_caller() causing ftrace_init() to bail. In such configurations, gcc/ld emits two types of trampolines for mcount(): 1. A long_branch, which has a single branch to mcount() for functions that are one hop away from mcount(): c0000000019e8544 <00031b56.long_branch._mcount>: c0000000019e8544: 4a 69 3f ac b c00000000007c4f0 <._mcount> 2. A plt_branch, for functions that are farther away from mcount(): c0000000051f33f8 <0008ba04.plt_branch._mcount>: c0000000051f33f8: 3d 82 ff a4 addis r12,r2,-92 c0000000051f33fc: e9 8c 04 20 ld r12,1056(r12) c0000000051f3400: 7d 89 03 a6 mtctr r12 c0000000051f3404: 4e 80 04 20 bctr We can reuse those trampolines for ftrace if we can have those trampolines go to ftrace_caller() instead. However, with ABIv2, we cannot depend on r2 being valid. As such, we use only the long_branch trampolines by patching those to instead branch to ftrace_caller or ftrace_regs_caller. In addition, we add additional trampolines around .text and .init.text to catch locations that are covered by the plt branches. This allows ftrace to work with most large kernel configurations. For now, we always patch the trampolines to go to ftrace_regs_caller, which is slightly inefficient. This can be optimized further at a later point. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-11powerpc/kbuild: move -mprofile-kernel check to KconfigNicholas Piggin
This eliminates the workaround that requires disabling -mprofile-kernel by default in Kconfig. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-03powerpc: Only support DYNAMIC_FTRACE not staticMichael Ellerman
We've had dynamic ftrace support for over 9 years since Steve first wrote it, all the distros use dynamic, and static is basically untested these days, so drop support for static ftrace. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-03powerpc64/ftrace: Implement support for ftrace_regs_caller()Naveen N. Rao
With -mprofile-kernel, we always save the full register state in ftrace_caller(). While this works, this is inefficient if we're not interested in the register state, such as when we're using the function tracer. Rename the existing ftrace_caller() as ftrace_regs_caller() and provide a simpler implementation for ftrace_caller() that is used when registers are not required to be saved. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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