[Crash-utility] Re: [PATCH v2] arm64: support an X86_64 target on an ARM64 host

Allow "make target=X86_64" on an arm64 host to analyze x86_64 dumpfiles, mirroring the existing "make target=ARM64" support on an x86_64 host. The only host dependency was in the LKCD dump headers, which embed a "struct pt_regs" from <asm/ptrace.h>. The arm64 uapi header exports "struct user_pt_regs" instead, so add lkcd_x86_64_pt_regs.h, a copy of the x86_64 uapi definition used only when the X86_64 target is built on a non-x86_64 host. Also make the sticky target logic host aware, and reject live system debugging of an X86/X86_64 binary on an arm64 host. Assisted-by: Github Copilot CLI:claude-opus-5 Signed-off-by: Alexander Boyko <boy1284(a)gmail.com&gt; --- Makefile | 2 +- README | 2 ++ configure.c | 36 +++++++++++++++++++++++++++--- filesys.c | 4 ++++ lkcd_vmdump_v1.h | 4 ++++ lkcd_vmdump_v2_v3.h | 4 ++++ lkcd_x86_64_pt_regs.h | 51 +++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 99 insertions(+), 4 deletions(-) create mode 100644 lkcd_x86_64_pt_regs.h diff --git a/Makefile b/Makefile index 46c43a4..22154af 100644 --- a/Makefile +++ b/Makefile @@ -98,7 +98,7 @@ GENERIC_HFILES=defs.h xen_hyper_defs.h xen_dom0.h MCORE_HFILES=va_server.h vas_crash.h REDHAT_HFILES=netdump.h diskdump.h makedumpfile.h xendump.h kvmdump.h qemu-load.h vmcore.h LKCD_DUMP_HFILES=lkcd_vmdump_v1.h lkcd_vmdump_v2_v3.h lkcd_dump_v5.h \ - lkcd_dump_v7.h lkcd_dump_v8.h + lkcd_dump_v7.h lkcd_dump_v8.h lkcd_x86_64_pt_regs.h LKCD_OBSOLETE_HFILES=lkcd_fix_mem.h LKCD_TRACE_HFILES=lkcd_x86_trace.h IBM_HFILES=ibm_common.h diff --git a/README b/README index 69232eb..5c4d8f2 100644 --- a/README +++ b/README @@ -113,6 +113,8 @@ riscv64 dumpfiles may be built by typing "make target=RISCV64". o On an x86_64 host, an x86_64 binary that can be used to analyze loongarch64 dumpfiles may be built by typing "make target=LOONGARCH64". + o On an arm64 host, an arm64 binary that can be used to analyze + x86_64 dumpfiles may be built by typing "make target=X86_64". Traditionally when vmcores are compressed via the makedumpfile(8) facility the libz compression library is used, and by default the crash utility diff --git a/configure.c b/configure.c index fd7b533..1732001 100644 --- a/configure.c +++ b/configure.c @@ -182,6 +182,7 @@ void add_extra_lib(char *); #define GDB_TARGET_MIPS_ON_X86_64 "GDB_CONF_FLAGS=--target=mipsel-elf-linux CFLAGS=-m32 CXXFLAGS=-m32" #define GDB_TARGET_RISCV64_ON_X86_64 "GDB_CONF_FLAGS=--target=riscv64-unknown-linux-gnu" #define GDB_TARGET_LOONGARCH64_ON_X86_64 "GDB_CONF_FLAGS=--target=loongarch64-unknown-linux-gnu" +#define GDB_TARGET_X86_64_ON_ARM64 "GDB_CONF_FLAGS=--target=x86_64-pc-linux-gnu" /* * The original plan was to allow the use of a particular version @@ -474,6 +475,12 @@ get_current_configuration(struct supported_gdb_version *sp) * Build an ARM64 crash binary on an X86_64 host. */ target_data.target = ARM64; + } else if ((target_data.target == ARM64) && + (name_to_target((char *)target_data.target_as_param) == X86_64)) { + /* + * Build an X86_64 crash binary on an ARM64 host. + */ + target_data.target = X86_64; } else if ((target_data.target == X86_64) && (name_to_target((char *)target_data.target_as_param) == PPC64)) { /* @@ -570,11 +577,32 @@ get_current_configuration(struct supported_gdb_version *sp) (target_data.initial_gdb_target != X86)) arch_mismatch(sp); + if ((target_data.initial_gdb_target == X86_64) && + (target_data.target != X86_64) && + (target_data.host == ARM64)) { + if (target_data.target == ARM64) { + /* + * An X86_64 cross gdb built on an ARM64 host is sticky. + */ + target_data.target = X86_64; + } else + arch_mismatch(sp); + } + if ((target_data.initial_gdb_target == ARM64) && (target_data.target != ARM64)) { - if (target_data.target == X86_64) + if (target_data.host == ARM64) { + /* + * The gdb in this tree is a native ARM64 gdb; it cannot + * serve any other target, so a clean rebuild is required. + */ + arch_mismatch(sp); + } else if (target_data.host == X86_64 && target_data.target == X86_64) { + /* + * An ARM64 cross gdb built on an X86_64 host is sticky. + */ target_data.target = ARM64; - else + } else arch_mismatch(sp); } if ((target_data.target == ARM64) && @@ -787,7 +815,9 @@ build_configure(struct supported_gdb_version *sp) break; case X86_64: target = TARGET_X86_64; - target_CFLAGS = TARGET_CFLAGS_X86_64; + target_CFLAGS = TARGET_CFLAGS_X86_64; + if (target_data.host == ARM64) + gdb_conf_flags = GDB_TARGET_X86_64_ON_ARM64; break; case ARM: target = TARGET_ARM; diff --git a/filesys.c b/filesys.c index 7ff4787..f5b79e7 100644 --- a/filesys.c +++ b/filesys.c @@ -4574,4 +4574,8 @@ check_live_arch_mismatch(void) if (machine_type("PPC")) error(FATAL, "compiled for the PPC architecture\n"); #endif +#ifdef __aarch64__ + if (machine_type("X86_64")) + error(FATAL, "compiled for the X86_64 architecture\n"); +#endif } diff --git a/lkcd_vmdump_v1.h b/lkcd_vmdump_v1.h index 3ffb219..0540a1f 100644 --- a/lkcd_vmdump_v1.h +++ b/lkcd_vmdump_v1.h @@ -35,8 +35,12 @@ #endif #ifndef IA64 typedef unsigned int u32; +#if defined(X86_64) && !defined(__x86_64__) +#include "lkcd_x86_64_pt_regs.h" /* for pt_regs */ +#else #include <asm/ptrace.h> /* for pt_regs */ #endif +#endif /* necessary header definitions in all cases */ #define DUMP_KIOBUF_NUMBER 0xdeadbeef /* special number for kiobuf maps */ diff --git a/lkcd_vmdump_v2_v3.h b/lkcd_vmdump_v2_v3.h index f215446..2b47141 100644 --- a/lkcd_vmdump_v2_v3.h +++ b/lkcd_vmdump_v2_v3.h @@ -104,8 +104,12 @@ typedef struct _dump_header_asm_s { #ifndef IA64 typedef unsigned int u32; +#if defined(X86_64) && !defined(__x86_64__) +#include "lkcd_x86_64_pt_regs.h" /* for pt_regs */ +#else #include <asm/ptrace.h> /* for pt_regs */ #endif +#endif /* definitions */ #define DUMP_ASM_MAGIC_NUMBER 0xdeaddeadULL /* magic number */ diff --git a/lkcd_x86_64_pt_regs.h b/lkcd_x86_64_pt_regs.h new file mode 100644 index 0000000..39240d0 --- /dev/null +++ b/lkcd_x86_64_pt_regs.h @@ -0,0 +1,51 @@ +/* lkcd_x86_64_pt_regs.h - core analysis suite + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +/* + * The LKCD dump headers embed the host kernel's "struct pt_regs", which is + * normally picked up from <asm/ptrace.h>. When the X86_64 target is built + * on a non-x86_64 host, that header describes the host architecture and does + * not export an x86_64 "struct pt_regs" at all, so the definition below is + * used instead. It is a verbatim copy of "struct pt_regs" from + * arch/x86/include/uapi/asm/ptrace.h, which keeps the LKCD dump + * header layout identical to a native x86_64 build. + */ + +#ifndef _LKCD_X86_64_PT_REGS_H +#define _LKCD_X86_64_PT_REGS_H + +struct pt_regs { + unsigned long r15; + unsigned long r14; + unsigned long r13; + unsigned long r12; + unsigned long rbp; + unsigned long rbx; + unsigned long r11; + unsigned long r10; + unsigned long r9; + unsigned long r8; + unsigned long rax; + unsigned long rcx; + unsigned long rdx; + unsigned long rsi; + unsigned long rdi; + unsigned long orig_rax; + unsigned long rip; + unsigned long cs; + unsigned long eflags; + unsigned long rsp; + unsigned long ss; +}; + +#endif /* _LKCD_X86_64_PT_REGS_H */