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2023-02-01objtool: Optimize layout of struct special_altThomas Weißschuh1-1/+1
Reduce the size of struct special_alt from 72 to 64 bytes. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-7-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Optimize layout of struct symbolThomas Weißschuh1-3/+2
Reduce the size of struct symbol on x86_64 from 208 to 200 bytes. This structure is allocated a lot and never freed. This reduces maximum memory usage while processing vmlinux.o from 2919716 KB to 2917988 KB (-0.5%) on my notebooks "localmodconfig". Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-6-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Allocate multiple structures with calloc()Thomas Weißschuh2-21/+25
By using calloc() instead of malloc() in a loop, libc does not have to keep around bookkeeping information for each single structure. This reduces maximum memory usage while processing vmlinux.o from 3153325 KB to 3035668 KB (-3.7%) on my notebooks "localmodconfig". Note this introduces memory leaks, because some additional structs get added to the lists later after reading the symbols and sections from the original object. Luckily we don't really care about memory leaks in objtool. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-3-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Make struct check_options staticThomas Weißschuh2-3/+1
It is not used outside of builtin-check.c. Also remove the unused declaration from builtin.h . Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-2-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Make struct entries[] static and constThomas Weißschuh1-3/+3
This data is not modified and not used outside of special.c. Also adapt its users to the constness. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/20221216-objtool-memory-v2-1-17968f85a464@weissschuh.net Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-02-01objtool: Fix HOSTCC flag usageIan Rogers1-12/+15
HOSTCC is always wanted when building objtool. Setting CC to HOSTCC happens after tools/scripts/Makefile.include is included, meaning flags (like CFLAGS) are set assuming say CC is gcc, but then it can be later set to HOSTCC which may be clang. tools/scripts/Makefile.include is needed for host set up and common macros in objtool's Makefile. Rather than override the CC variable to HOSTCC, just pass CC as HOSTCC to the sub-makes of Makefile.build, the libsubcmd builds and also to the linkage step. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20230126190606.40739-4-irogers@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-01-31Merge tag 'v6.2-rc6' into sched/core, to pick up fixesIngo Molnar1-0/+9
Pick up fixes before merging another batch of cpuidle updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2023-01-30objtool: Properly support make V=1Ian Rogers1-4/+10
The Q variable was being used but never correctly set up. Add the setting up and use in place of @. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20230126190606.40739-3-irogers@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-01-30objtool: Install libsubcmd in buildIan Rogers3-10/+24
Including from tools/lib can create inadvertent dependencies. Install libsubcmd in the objtool build and then include the headers from there. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20230126190606.40739-2-irogers@google.com Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
2023-01-21objtool: Check that module init/exit function is an indirect call targetMichal Kubecek2-0/+15
Some out-of-tree modules still do not use module_init() / module_exit() macros and simply create functions with magic names init_module() and cleanup_module() instead. As a result, these functions are not recognized as indirect call targets by objtool and such module fails to load into an IBT enabled kernel. This old way is not even documented any more but it is cleaner to issue a warning than to let the module fail on load without obvious reason. Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230118105215.B9DA960514@lion.mk-sys.cz
2023-01-13entry, kasan, x86: Disallow overriding mem*() functionsPeter Zijlstra1-0/+3
KASAN cannot just hijack the mem*() functions, it needs to emit __asan_mem*() variants if it wants instrumentation (other sanitizers already do this). vmlinux.o: warning: objtool: sync_regs+0x24: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: vc_switch_off_ist+0xbe: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: fixup_bad_iret+0x36: call to memset() leaves .noinstr.text section vmlinux.o: warning: objtool: __sev_get_ghcb+0xa0: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: __sev_put_ghcb+0x35: call to memcpy() leaves .noinstr.text section Remove the weak aliases to ensure nobody hijacks these functions and add them to the noinstr section. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195542.028523143@infradead.org
2023-01-13ubsan: Fix objtool UACCESS warnsPeter Zijlstra1-0/+1
clang-14 allyesconfig gives: vmlinux.o: warning: objtool: emulator_cmpxchg_emulated+0x705: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: paging64_update_accessed_dirty_bits+0x39e: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: paging32_update_accessed_dirty_bits+0x390: call to __ubsan_handle_load_invalid_value() with UACCESS enabled vmlinux.o: warning: objtool: ept_update_accessed_dirty_bits+0x43f: call to __ubsan_handle_load_invalid_value() with UACCESS enabled Add the required eflags save/restore and whitelist the thing. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195541.906007455@infradead.org
2023-01-13objtool/idle: Validate __cpuidle code as noinstrPeter Zijlstra1-0/+13
Idle code is very like entry code in that RCU isn't available. As such, add a little validation. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org
2023-01-09objtool: Tolerate STT_NOTYPE symbols at end of sectionNicholas Piggin1-0/+9
Hand-written asm often contains non-function symbols in executable sections. _end symbols for finding the size of instruction blocks for runtime processing is one such usage. optprobe_template_end is one example that causes the warning: objtool: optprobe_template_end(): can't find starting instruction This is because the symbol happens to be at the end of the file (and therefore end of a section in the object file). So ignore end-of-section STT_NOTYPE symbols instead of bailing out because an instruction can't be found. While we're here, add a more descriptive warning for STT_FUNC symbols found at the end of a section. [ This also solves a PowerPC regression reported by Sathvika Vasireddy. ] Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reported-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Sathvika Vasireddy <sv@linux.ibm.com> Link: https://lore.kernel.org/r/20221220101323.3119939-1-npiggin@gmail.com
2023-01-07objtool: Fix memory leak in create_static_call_sections()Miaoqian Lin1-0/+2
strdup() allocates memory for key_name. We need to release the memory in the following error paths. Add free() to avoid memory leak. Fixes: 1e7e47883830 ("x86/static_call: Add inline static call implementation for x86-64") Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20221205080642.558583-1-linmq006@gmail.com Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
2023-01-05x86/alternatives: Add alt_instr.flagsBorislav Petkov (AMD)1-3/+3
Add a struct alt_instr.flags field which will contain different flags controlling alternatives patching behavior. The initial idea was to be able to specify it as a separate macro parameter but that would mean touching all possible invocations of the alternatives macros and thus a lot of churn. What is more, as PeterZ suggested, being able to say ALT_NOT(feature) is very readable and explains exactly what is meant. So make the feature field a u32 where the patching flags are the upper u16 part of the dword quantity while the lower u16 word is the feature. The highest feature number currently is 0x26a (i.e., word 19) so there is plenty of space. If that becomes insufficient, the field can be extended to u64 which will then make struct alt_instr of the nice size of 16 bytes (14 bytes currently). There should be no functional changes resulting from this. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/Y6RCoJEtxxZWwotd@zn.tnic
2022-12-19Merge tag 'powerpc-6.2-1' of ↵Linus Torvalds19-56/+269
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Add powerpc qspinlock implementation optimised for large system scalability and paravirt. See the merge message for more details - Enable objtool to be built on powerpc to generate mcount locations - Use a temporary mm for code patching with the Radix MMU, so the writable mapping is restricted to the patching CPU - Add an option to build the 64-bit big-endian kernel with the ELFv2 ABI - Sanitise user registers on interrupt entry on 64-bit Book3S - Many other small features and fixes Thanks to Aboorva Devarajan, Angel Iglesias, Benjamin Gray, Bjorn Helgaas, Bo Liu, Chen Lifu, Christoph Hellwig, Christophe JAILLET, Christophe Leroy, Christopher M. Riedl, Colin Ian King, Deming Wang, Disha Goel, Dmitry Torokhov, Finn Thain, Geert Uytterhoeven, Gustavo A. R. Silva, Haowen Bai, Joel Stanley, Jordan Niethe, Julia Lawall, Kajol Jain, Laurent Dufour, Li zeming, Miaoqian Lin, Michael Jeanson, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Miehlbradt, Nicholas Piggin, Pali Rohár, Randy Dunlap, Rohan McLure, Russell Currey, Sathvika Vasireddy, Shaomin Deng, Stephen Kitt, Stephen Rothwell, Thomas Weißschuh, Tiezhu Yang, Uwe Kleine-König, Xie Shaowen, Xiu Jianfeng, XueBing Chen, Yang Yingliang, Zhang Jiaming, ruanjinjie, Jessica Yu, and Wolfram Sang. * tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (181 commits) powerpc/code-patching: Fix oops with DEBUG_VM enabled powerpc/qspinlock: Fix 32-bit build powerpc/prom: Fix 32-bit build powerpc/rtas: mandate RTAS syscall filtering powerpc/rtas: define pr_fmt and convert printk call sites powerpc/rtas: clean up includes powerpc/rtas: clean up rtas_error_log_max initialization powerpc/pseries/eeh: use correct API for error log size powerpc/rtas: avoid scheduling in rtas_os_term() powerpc/rtas: avoid device tree lookups in rtas_os_term() powerpc/rtasd: use correct OF API for event scan rate powerpc/rtas: document rtas_call() powerpc/pseries: unregister VPA when hot unplugging a CPU powerpc/pseries: reset the RCU watchdogs after a LPM powerpc: Take in account addition CPU node when building kexec FDT powerpc: export the CPU node count powerpc/cpuidle: Set CPUIDLE_FLAG_POLLING for snooze state powerpc/dts/fsl: Fix pca954x i2c-mux node names cxl: Remove unnecessary cxl_pci_window_alignment() selftests/powerpc: Fix resource leaks ...
2022-12-14Merge tag 'x86_core_for_v6.2' of ↵Linus Torvalds10-182/+566
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Add the call depth tracking mitigation for Retbleed which has been long in the making. It is a lighterweight software-only fix for Skylake-based cores where enabling IBRS is a big hammer and causes a significant performance impact. What it basically does is, it aligns all kernel functions to 16 bytes boundary and adds a 16-byte padding before the function, objtool collects all functions' locations and when the mitigation gets applied, it patches a call accounting thunk which is used to track the call depth of the stack at any time. When that call depth reaches a magical, microarchitecture-specific value for the Return Stack Buffer, the code stuffs that RSB and avoids its underflow which could otherwise lead to the Intel variant of Retbleed. This software-only solution brings a lot of the lost performance back, as benchmarks suggest: https://lore.kernel.org/all/20220915111039.092790446@infradead.org/ That page above also contains a lot more detailed explanation of the whole mechanism - Implement a new control flow integrity scheme called FineIBT which is based on the software kCFI implementation and uses hardware IBT support where present to annotate and track indirect branches using a hash to validate them - Other misc fixes and cleanups * tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits) x86/paravirt: Use common macro for creating simple asm paravirt functions x86/paravirt: Remove clobber bitmask from .parainstructions x86/debug: Include percpu.h in debugreg.h to get DECLARE_PER_CPU() et al x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit x86/Kconfig: Enable kernel IBT by default x86,pm: Force out-of-line memcpy() objtool: Fix weak hole vs prefix symbol objtool: Optimize elf_dirty_reloc_sym() x86/cfi: Add boot time hash randomization x86/cfi: Boot time selection of CFI scheme x86/ibt: Implement FineIBT objtool: Add --cfi to generate the .cfi_sites section x86: Add prefix symbols for function padding objtool: Add option to generate prefix symbols objtool: Avoid O(bloody terrible) behaviour -- an ode to libelf objtool: Slice up elf_create_section_symbol() kallsyms: Revert "Take callthunks into account" x86: Unconfuse CONFIG_ and X86_FEATURE_ namespaces x86/retpoline: Fix crash printing warning x86/paravirt: Fix a !PARAVIRT build warning ...
2022-11-23objtool/powerpc: Implement arch_pc_relative_reloc()Michael Ellerman2-0/+11
Provide an implementation for arch_pc_relative_reloc(). It is needed to pass the build once 61c6065ef7ec ("objtool: Allow !PC relative relocations") is merged. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2022-11-18objtool/powerpc: Add --mcount specific implementationSathvika Vasireddy2-0/+18
This patch enables objtool --mcount on powerpc, and adds implementation specific to powerpc. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-17-sv@linux.ibm.com
2022-11-18objtool/powerpc: Enable objtool to be built on ppcSathvika Vasireddy6-0/+146
This patch adds [stub] implementations for required functions, inorder to enable objtool build on powerpc. [Christophe Leroy: powerpc: Add missing asm/asm.h for objtool, Use local variables for type and imm in arch_decode_instruction(), Adapt len for prefixed instructions.] Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sathvika Vasireddy <sv@linux.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/20221114175754.1131267-16-sv@linux.ibm.com
2022-11-18objtool: Add arch specific function arch_ftrace_match()Sathvika Vasireddy3-1/+8
Add architecture specific function to look for relocation records pointing to architecture specific symbols. Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-15-sv@linux.ibm.com
2022-11-18objtool: Use macros to define arch specific reloc typesSathvika Vasireddy2-1/+3
Make relocation types architecture specific. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-14-sv@linux.ibm.com
2022-11-18objtool: Read special sections with alts only when specific options are selectedSathvika Vasireddy1-3/+5
Call add_special_section_alts() only when stackval or orc or uaccess or noinstr options are passed to objtool. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-13-sv@linux.ibm.com
2022-11-18objtool: Add --mnop as an option to --mcountSathvika Vasireddy3-9/+25
Some architectures (powerpc) may not support ftrace locations being nop'ed out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as a means for architectures to enable nop'ing of ftrace locations. Add --mnop as an option to objtool --mcount, to indicate support for the same. Also, make sure that --mnop can be passed as an option to objtool only when --mcount is passed. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-12-sv@linux.ibm.com
2022-11-18objtool: Use target file class size instead of a compiled constantChristophe Leroy3-10/+24
In order to allow using objtool on cross-built kernels, determine size of long from elf data instead of using sizeof(long) at build time. For the time being this covers only mcount. [Sathvika Vasireddy: Rename variable "size" to "addrsize" and function "elf_class_size()" to "elf_class_addrsize()", and modify create_mcount_loc_sections() function to follow reverse christmas tree format to order local variable declarations.] Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-11-sv@linux.ibm.com
2022-11-18objtool: Use target file endianness instead of a compiled constantChristophe Leroy6-31/+30
Some architectures like powerpc support both endianness, it's therefore not possible to fix the endianness via arch/endianness.h because there is no easy way to get the target endianness at build time. Use the endianness recorded in the file objtool is working on. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-10-sv@linux.ibm.com
2022-11-18objtool: Fix SEGFAULTChristophe Leroy1-1/+1
find_insn() will return NULL in case of failure. Check insn in order to avoid a kernel Oops for NULL pointer dereference. Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20221114175754.1131267-9-sv@linux.ibm.com
2022-11-05objtool: Fix weak hole vs prefix symbolPeter Zijlstra1-1/+21
Boris (and the robot) reported that objtool grew a new complaint about unreachable instructions. Upon inspection it was immediately clear the __weak zombie instructions struck again. For the unweary, the linker will simply remove the symbol for overriden __weak symbols but leave the instructions in place, creating unreachable instructions -- and objtool likes to report these. Commit 4adb23686795 ("objtool: Ignore extra-symbol code") was supposed to have dealt with that, but the new commit 9f2899fe36a6 ("objtool: Add option to generate prefix symbols") subtly broke that logic by created unvisited symbols. Fixes: 9f2899fe36a6 ("objtool: Add option to generate prefix symbols") Reported-by: Borislav Petkov <bp@alien8.de> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-11-05objtool: Optimize elf_dirty_reloc_sym()Peter Zijlstra2-17/+12
When moving a symbol in the symtab its index changes and any reloc referring that symtol-table-index will need to be rewritten too. In order to facilitate this, objtool simply marks the whole reloc section 'changed' which will cause the whole section to be re-generated. However, finding the relocs that use any given symbol is implemented rather crudely -- a fully iteration of all sections and their relocs. Given that some builds have over 20k sections (kallsyms etc..) iterating all that for *each* symbol moved takes a bit of time. Instead have each symbol keep a list of relocs that reference it. This *vastly* improves build times for certain configs. Reported-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/Y2LlRA7x+8UsE1xf@hirez.programming.kicks-ass.net
2022-11-01objtool: Add --cfi to generate the .cfi_sites sectionPeter Zijlstra3-0/+71
Add the location of all __cfi_##name symbols (as generated by kCFI) to a section such that we might re-write things at kernel boot. Notably; boot time re-hashing and FineIBT are the intended use of this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20221027092842.568039454@infradead.org
2022-11-01objtool: Add option to generate prefix symbolsPeter Zijlstra5-1/+67
When code is compiled with: -fpatchable-function-entry=${PADDING_BYTES},${PADDING_BYTES} functions will have PADDING_BYTES of NOP in front of them. Unwinders and other things that symbolize code locations will typically attribute these bytes to the preceding function. Given that these bytes nominally belong to the following symbol this mis-attribution is confusing. Inspired by the fact that CFI_CLANG emits __cfi_##name symbols to claim these bytes, allow objtool to emit __pfx_##name symbols to do the same. Therefore add the objtool --prefix=N argument, to conditionally place a __pfx_##name symbol at N bytes ahead of symbol 'name' when: all these preceding bytes are NOP and name-N is an instruction boundary. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yujie Liu <yujie.liu@intel.com> Link: https://lkml.kernel.org/r/20221028194453.526899822@infradead.org
2022-11-01objtool: Avoid O(bloody terrible) behaviour -- an ode to libelfPeter Zijlstra2-7/+84
Due to how gelf_update_sym*() requires an Elf_Data pointer, and how libelf keeps Elf_Data in a linked list per section, elf_update_symbol() ends up having to iterate this list on each update to find the correct Elf_Data for the index'ed symbol. By allocating one Elf_Data per new symbol, the list grows per new symbol, giving an effective O(n^2) insertion time. This is obviously bloody terrible. Therefore over-allocate the Elf_Data when an extention is needed. Except it turns out libelf disregards Elf_Scn::sh_size in favour of the sum of Elf_Data::d_size. IOW it will happily write out all the unused space and fill it with: 0000000000000000 0 NOTYPE LOCAL DEFAULT UND entries (aka zeros). Which obviously violates the STB_LOCAL placement rule, and is a general pain in the backside for not being the desired behaviour. Manually fix-up the Elf_Data size to avoid this problem before calling elf_update(). This significantly improves performance when adding a significant number of symbols. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yujie Liu <yujie.liu@intel.com> Link: https://lkml.kernel.org/r/20221028194453.461658986@infradead.org
2022-11-01objtool: Slice up elf_create_section_symbol()Peter Zijlstra1-21/+35
In order to facilitate creation of more symbol types, slice up elf_create_section_symbol() to extract a generic helper that deals with adding ELF symbols. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yujie Liu <yujie.liu@intel.com> Link: https://lkml.kernel.org/r/20221028194453.396634875@infradead.org
2022-10-18objtool, kcsan: Add volatile read/write instrumentation to whitelistMarco Elver1-0/+10
Adds KCSAN's volatile instrumentation to objtool's uaccess whitelist. Recent kernel change have shown that this was missing from the uaccess whitelist (since the first upstreamed version of KCSAN): mm/gup.o: warning: objtool: fault_in_readable+0x101: call to __tsan_volatile_write1() with UACCESS enabled Fixes: 75d75b7a4d54 ("kcsan: Support distinguishing volatile accesses") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-10-17objtool: Allow STT_NOTYPE -> STT_FUNC+0 sibling-callsPeter Zijlstra1-27/+47
Teach objtool about STT_NOTYPE -> STT_FUNC+0 sibling calls. Doing do allows slightly simpler .S files. There is a slight complication in that we specifically do not want to allow sibling calls from symbol holes (previously covered by STT_WEAK symbols) -- such things exist where a weak function has a .cold subfunction for example. Additionally, STT_NOTYPE tail-calls are allowed to happen with a modified stack frame, they don't need to obey the normal rules after all. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-10-17objtool: Rework instruction -> symbol mappingPeter Zijlstra2-51/+66
Currently insn->func contains a instruction -> symbol link for STT_FUNC symbols. A NULL value is assumed to mean STT_NOTYPE. However, there are also instructions not covered by any symbol at all. This can happen due to __weak symbols for example. Since the current scheme cannot differentiate between no symbol and STT_NOTYPE symbol, change things around. Make insn->sym point to any symbol type such that !insn->sym means no symbol and add a helper insn_func() that check the sym->type to retain the old functionality. This then prepares the way to add code that depends on the distinction between STT_NOTYPE and no symbol at all. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-10-17objtool: Allow symbol range comparisons for IBT/ENDBRPeter Zijlstra1-0/+28
A semi common pattern is where code checks if a code address is within a specific range. All text addresses require either ENDBR or ANNOTATE_ENDBR, however the ANNOTATE_NOENDBR past the range is unnatural. Instead, suppress this warning when this is exactly at the end of a symbol that itself starts with either ENDBR/ANNOTATE_ENDBR. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.434642471@infradead.org
2022-10-17objtool: Fix find_{symbol,func}_containing()Peter Zijlstra2-54/+42
The current find_{symbol,func}_containing() functions are broken in the face of overlapping symbols, exactly the case that is needed for a new ibt/endbr supression. Import interval_tree_generic.h into the tools tree and convert the symbol tree to an interval tree to support proper range stabs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.330203761@infradead.org
2022-10-17objtool: Add --hacks=skylakePeter Zijlstra3-5/+13
Make the call/func sections selectable via the --hacks option. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.120821440@infradead.org
2022-10-17objtool: Add .call_sites sectionPeter Zijlstra3-0/+53
In preparation for call depth tracking provide a section which collects all direct calls. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111146.016511961@infradead.org
2022-10-17objtool: Track init sectionPeter Zijlstra2-8/+11
For future usage of .init.text exclusion track the init section in the instruction decoder and use the result in retpoline validation. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.910334431@infradead.org
2022-10-17objtool: Allow !PC relative relocationsPeter Zijlstra3-1/+27
Objtool doesn't currently much like per-cpu usage in alternatives: arch/x86/entry/entry_64.o: warning: objtool: .altinstr_replacement+0xf: unsupported relocation in alternatives section f: 65 c7 04 25 00 00 00 00 00 00 00 80 movl $0x80000000,%gs:0x0 13: R_X86_64_32S __x86_call_depth Since the R_X86_64_32S relocation is location invariant (it's computation doesn't include P - the address of the location itself), it can be trivially allowed. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220915111145.806607235@infradead.org
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds1-0/+20
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-10Merge tag 'objtool-core-2022-10-07' of ↵Linus Torvalds2-4/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - Remove the "ANNOTATE_NOENDBR on ENDBR" warning: it's not really useful and only found a non-bug false positive so far. - Properly decode LOOP/LOOPE/LOOPNE, which were missing from the x86 decoder. Because these instructions are rather ineffective, they never showed up in compiler output, but they are simple enough to support, so add them for completeness. - A bit more cross-arch preparatory work. * tag 'objtool-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool,x86: Teach decode about LOOP* instructions objtool: Remove "ANNOTATE_NOENDBR on ENDBR" warning objtool: Use arch_jump_destination() in read_intra_function_calls()
2022-10-04Merge tag 'net-next-6.1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Introduce and use a single page frag cache for allocating small skb heads, clawing back the 10-20% performance regression in UDP flood test from previous fixes. - Run packets which already went thru HW coalescing thru SW GRO. This significantly improves TCP segment coalescing and simplifies deployments as different workloads benefit from HW or SW GRO. - Shrink the size of the base zero-copy send structure. - Move TCP init under a new slow / sleepable version of DO_ONCE(). BPF: - Add BPF-specific, any-context-safe memory allocator. - Add helpers/kfuncs for PKCS#7 signature verification from BPF programs. - Define a new map type and related helpers for user space -> kernel communication over a ring buffer (BPF_MAP_TYPE_USER_RINGBUF). - Allow targeting BPF iterators to loop through resources of one task/thread. - Add ability to call selected destructive functions. Expose crash_kexec() to allow BPF to trigger a kernel dump. Use CAP_SYS_BOOT check on the loading process to judge permissions. - Enable BPF to collect custom hierarchical cgroup stats efficiently by integrating with the rstat framework. - Support struct arguments for trampoline based programs. Only structs with size <= 16B and x86 are supported. - Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping sockets (instead of just TCP and UDP sockets). - Add a helper for accessing CLOCK_TAI for time sensitive network related programs. - Support accessing network tunnel metadata's flags. - Make TCP SYN ACK RTO tunable by BPF programs with TCP Fast Open. - Add support for writing to Netfilter's nf_conn:mark. Protocols: - WiFi: more Extremely High Throughput (EHT) and Multi-Link Operation (MLO) work (802.11be, WiFi 7). - vsock: improve support for SO_RCVLOWAT. - SMC: support SO_REUSEPORT. - Netlink: define and document how to use netlink in a "modern" way. Support reporting missing attributes via extended ACK. - IPSec: support collect metadata mode for xfrm interfaces. - TCPv6: send consistent autoflowlabel in SYN_RECV state and RST packets. - TCP: introduce optional per-netns connection hash table to allow better isolation between namespaces (opt-in, at the cost of memory and cache pressure). - MPTCP: support TCP_FASTOPEN_CONNECT. - Add NEXT-C-SID support in Segment Routing (SRv6) End behavior. - Adjust IP_UNICAST_IF sockopt behavior for connected UDP sockets. - Open vSwitch: - Allow specifying ifindex of new interfaces. - Allow conntrack and metering in non-initial user namespace. - TLS: support the Korean ARIA-GCM crypto algorithm. - Remove DECnet support. Driver API: - Allow selecting the conduit interface used by each port in DSA switches, at runtime. - Ethernet Power Sourcing Equipment and Power Device support. - Add tc-taprio support for queueMaxSDU parameter, i.e. setting per traffic class max frame size for time-based packet schedules. - Support PHY rate matching - adapting between differing host-side and link-side speeds. - Introduce QUSGMII PHY mode and 1000BASE-KX interface mode. - Validate OF (device tree) nodes for DSA shared ports; make phylink-related properties mandatory on DSA and CPU ports. Enforcing more uniformity should allow transitioning to phylink. - Require that flash component name used during update matches one of the components for which version is reported by info_get(). - Remove "weight" argument from driver-facing NAPI API as much as possible. It's one of those magic knobs which seemed like a good idea at the time but is too indirect to use in practice. - Support offload of TLS connections with 256 bit keys. New hardware / drivers: - Ethernet: - Microchip KSZ9896 6-port Gigabit Ethernet Switch - Renesas Ethernet AVB (EtherAVB-IF) Gen4 SoCs - Analog Devices ADIN1110 and ADIN2111 industrial single pair Ethernet (10BASE-T1L) MAC+PHY. - Rockchip RV1126 Gigabit Ethernet (a version of stmmac IP). - Ethernet SFPs / modules: - RollBall / Hilink / Turris 10G copper SFPs - HALNy GPON module - WiFi: - CYW43439 SDIO chipset (brcmfmac) - CYW89459 PCIe chipset (brcmfmac) - BCM4378 on Apple platforms (brcmfmac) Drivers: - CAN: - gs_usb: HW timestamp support - Ethernet PHYs: - lan8814: cable diagnostics - Ethernet NICs: - Intel (100G): - implement control of FCS/CRC stripping - port splitting via devlink -