user/sven/linux.git/tools/objtool, branch v6.2-rc5

objtool: Tolerate STT_NOTYPE symbols at end of section

2023-01-09T16:53:46Z

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 Reported-by: Sathvika Vasireddy Signed-off-by: Nicholas Piggin Signed-off-by: Ingo Molnar Acked-by: Sathvika Vasireddy Link: https://lore.kernel.org/r/20221220101323.3119939-1-npiggin@gmail.com

Merge tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-12-19T13:13:33Z

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 ...

Merge tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-12-14T23:03:00Z

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 ...

objtool/powerpc: Implement arch_pc_relative_reloc()

2022-11-23T10:26:10Z

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

objtool/powerpc: Add --mcount specific implementation

2022-11-18T08:00:16Z

This patch enables objtool --mcount on powerpc, and adds implementation specific to powerpc. Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Reviewed-by: Christophe Leroy Acked-by: Josh Poimboeuf Signed-off-by: Sathvika Vasireddy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-17-sv@linux.ibm.com

objtool/powerpc: Enable objtool to be built on ppc

2022-11-18T08:00:16Z

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 Reviewed-by: Naveen N. Rao Acked-by: Josh Poimboeuf Signed-off-by: Sathvika Vasireddy Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-16-sv@linux.ibm.com

objtool: Add arch specific function arch_ftrace_match()

2022-11-18T08:00:16Z

Add architecture specific function to look for relocation records pointing to architecture specific symbols. Suggested-by: Christophe Leroy Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Reviewed-by: Christophe Leroy Acked-by: Josh Poimboeuf Signed-off-by: Sathvika Vasireddy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-15-sv@linux.ibm.com

objtool: Use macros to define arch specific reloc types

2022-11-18T08:00:16Z

Make relocation types architecture specific. Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Reviewed-by: Christophe Leroy Acked-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Signed-off-by: Sathvika Vasireddy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-14-sv@linux.ibm.com

objtool: Read special sections with alts only when specific options are selected

2022-11-18T08:00:16Z

Call add_special_section_alts() only when stackval or orc or uaccess or noinstr options are passed to objtool. Tested-by: Naveen N. Rao Reviewed-by: Naveen N. Rao Reviewed-by: Christophe Leroy Acked-by: Josh Poimboeuf Signed-off-by: Sathvika Vasireddy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-13-sv@linux.ibm.com

objtool: Add --mnop as an option to --mcount

2022-11-18T08:00:16Z

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 Reviewed-by: Naveen N. Rao Acked-by: Josh Poimboeuf Reviewed-by: Christophe Leroy Signed-off-by: Sathvika Vasireddy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20221114175754.1131267-12-sv@linux.ibm.com