git: 1b196c07b81d - stable/13 - linux(4): implement coredump support
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Date: Fri, 17 Jun 2022 19:36:46 UTC
The branch stable/13 has been updated by dchagin:
URL: https://cgit.FreeBSD.org/src/commit/?id=1b196c07b81d1ec547a4e57567c352e93080c9e5
commit 1b196c07b81d1ec547a4e57567c352e93080c9e5
Author: Edward Tomasz Napierala <trasz@FreeBSD.org>
AuthorDate: 2021-06-30 16:45:21 +0000
Commit: Dmitry Chagin <dchagin@FreeBSD.org>
CommitDate: 2022-06-17 19:33:02 +0000
linux(4): implement coredump support
Implement dumping core for Linux binaries on amd64, for both
32- and 64-bit executables. Some bits are still missing.
This is based on a prototype by chuck@.
Reviewed By: kib
Sponsored By: EPSRC
Differential Revision: https://reviews.freebsd.org/D30019
(cherry picked from commit 447636e43c08d697664512a50f00f93f41c0a79f)
---
sys/amd64/linux/linux_machdep.c | 34 +++++
sys/amd64/linux/linux_ptrace.c | 33 -----
sys/amd64/linux/linux_sysvec.c | 4 +-
sys/amd64/linux32/linux32_sysvec.c | 6 +-
sys/arm64/linux/linux_sysvec.c | 4 +-
sys/compat/linux/linux_elf.c | 294 +++++++++++++++++++++++++++++++++++++
sys/compat/linux/linux_elf.h | 56 +++++++
sys/compat/linux/linux_elf32.c | 38 +++++
sys/compat/linux/linux_elf64.c | 38 +++++
sys/compat/linux/linux_emul.h | 6 +
sys/modules/linux/Makefile | 1 +
sys/modules/linux64/Makefile | 1 +
12 files changed, 475 insertions(+), 40 deletions(-)
diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c
index c2f841707974..84663a79972d 100644
--- a/sys/amd64/linux/linux_machdep.c
+++ b/sys/amd64/linux/linux_machdep.c
@@ -79,6 +79,7 @@ __FBSDID("$FreeBSD$");
#include <vm/vm_map.h>
#include <x86/ifunc.h>
+#include <x86/reg.h>
#include <x86/sysarch.h>
#include <security/audit/audit.h>
@@ -326,3 +327,36 @@ DEFINE_IFUNC(, int, futex_xorl, (int, uint32_t *, int *))
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
futex_xorl_smap : futex_xorl_nosmap);
}
+
+void
+bsd_to_linux_regset(struct reg *b_reg, struct linux_pt_regset *l_regset)
+{
+
+ l_regset->r15 = b_reg->r_r15;
+ l_regset->r14 = b_reg->r_r14;
+ l_regset->r13 = b_reg->r_r13;
+ l_regset->r12 = b_reg->r_r12;
+ l_regset->rbp = b_reg->r_rbp;
+ l_regset->rbx = b_reg->r_rbx;
+ l_regset->r11 = b_reg->r_r11;
+ l_regset->r10 = b_reg->r_r10;
+ l_regset->r9 = b_reg->r_r9;
+ l_regset->r8 = b_reg->r_r8;
+ l_regset->rax = b_reg->r_rax;
+ l_regset->rcx = b_reg->r_rcx;
+ l_regset->rdx = b_reg->r_rdx;
+ l_regset->rsi = b_reg->r_rsi;
+ l_regset->rdi = b_reg->r_rdi;
+ l_regset->orig_rax = b_reg->r_rax;
+ l_regset->rip = b_reg->r_rip;
+ l_regset->cs = b_reg->r_cs;
+ l_regset->eflags = b_reg->r_rflags;
+ l_regset->rsp = b_reg->r_rsp;
+ l_regset->ss = b_reg->r_ss;
+ l_regset->fs_base = 0;
+ l_regset->gs_base = 0;
+ l_regset->ds = b_reg->r_ds;
+ l_regset->es = b_reg->r_es;
+ l_regset->fs = b_reg->r_fs;
+ l_regset->gs = b_reg->r_gs;
+}
diff --git a/sys/amd64/linux/linux_ptrace.c b/sys/amd64/linux/linux_ptrace.c
index 13bc0edd7c98..770ebcf58364 100644
--- a/sys/amd64/linux/linux_ptrace.c
+++ b/sys/amd64/linux/linux_ptrace.c
@@ -246,39 +246,6 @@ map_regs_to_linux(struct reg *b_reg, struct linux_pt_reg *l_reg)
l_reg->ss = b_reg->r_ss;
}
-void
-bsd_to_linux_regset(struct reg *b_reg, struct linux_pt_regset *l_regset)
-{
-
- l_regset->r15 = b_reg->r_r15;
- l_regset->r14 = b_reg->r_r14;
- l_regset->r13 = b_reg->r_r13;
- l_regset->r12 = b_reg->r_r12;
- l_regset->rbp = b_reg->r_rbp;
- l_regset->rbx = b_reg->r_rbx;
- l_regset->r11 = b_reg->r_r11;
- l_regset->r10 = b_reg->r_r10;
- l_regset->r9 = b_reg->r_r9;
- l_regset->r8 = b_reg->r_r8;
- l_regset->rax = b_reg->r_rax;
- l_regset->rcx = b_reg->r_rcx;
- l_regset->rdx = b_reg->r_rdx;
- l_regset->rsi = b_reg->r_rsi;
- l_regset->rdi = b_reg->r_rdi;
- l_regset->orig_rax = b_reg->r_rax;
- l_regset->rip = b_reg->r_rip;
- l_regset->cs = b_reg->r_cs;
- l_regset->eflags = b_reg->r_rflags;
- l_regset->rsp = b_reg->r_rsp;
- l_regset->ss = b_reg->r_ss;
- l_regset->fs_base = 0;
- l_regset->gs_base = 0;
- l_regset->ds = b_reg->r_ds;
- l_regset->es = b_reg->r_es;
- l_regset->fs = b_reg->r_fs;
- l_regset->gs = b_reg->r_gs;
-}
-
static void
map_regs_from_linux(struct reg *b_reg, struct linux_pt_reg *l_reg)
{
diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
index 54870b0153c9..5237e32b614d 100644
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -735,8 +735,8 @@ struct sysentvec elf_linux_sysvec = {
.sv_name = "Linux ELF64",
.sv_coredump = elf64_coredump,
.sv_elf_core_osabi = ELFOSABI_NONE,
- .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
- .sv_elf_core_prepare_notes = elf64_prepare_notes,
+ .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
+ .sv_elf_core_prepare_notes = linux64_prepare_notes,
.sv_imgact_try = linux_exec_imgact_try,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_minuser = VM_MIN_ADDRESS,
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
index 13ba0c883c42..398ac51d4203 100644
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -903,9 +903,9 @@ struct sysentvec elf_linux_sysvec = {
.sv_szsigcode = &linux_szsigcode,
.sv_name = "Linux ELF32",
.sv_coredump = elf32_coredump,
- .sv_elf_core_osabi = ELFOSABI_FREEBSD,
- .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
- .sv_elf_core_prepare_notes = elf32_prepare_notes,
+ .sv_elf_core_osabi = ELFOSABI_NONE,
+ .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
+ .sv_elf_core_prepare_notes = linux32_prepare_notes,
.sv_imgact_try = linux_exec_imgact_try,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_minuser = VM_MIN_ADDRESS,
diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c
index 5a2edcefac2c..1b815b8ac0f2 100644
--- a/sys/arm64/linux/linux_sysvec.c
+++ b/sys/arm64/linux/linux_sysvec.c
@@ -404,8 +404,8 @@ struct sysentvec elf_linux_sysvec = {
.sv_name = "Linux ELF64",
.sv_coredump = elf64_coredump,
.sv_elf_core_osabi = ELFOSABI_NONE,
- .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
- .sv_elf_core_prepare_notes = elf64_prepare_notes,
+ .sv_elf_core_abi_vendor = LINUX_ABI_VENDOR,
+ .sv_elf_core_prepare_notes = linux64_prepare_notes,
.sv_imgact_try = linux_exec_imgact_try,
.sv_minsigstksz = LINUX_MINSIGSTKSZ,
.sv_minuser = VM_MIN_ADDRESS,
diff --git a/sys/compat/linux/linux_elf.c b/sys/compat/linux/linux_elf.c
new file mode 100644
index 000000000000..077e0c93c884
--- /dev/null
+++ b/sys/compat/linux/linux_elf.c
@@ -0,0 +1,294 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 2021 Edward Tomasz Napierala <trasz@FreeBSD.org>
+ * Copyright (c) 2018 Chuck Tuffli
+ * Copyright (c) 2017 Dell EMC
+ * Copyright (c) 2000 David O'Brien
+ * Copyright (c) 1995-1996 Søren Schmidt
+ * Copyright (c) 1996 Peter Wemm
+ * All rights reserved.
+ *
+ * This software was developed by the University of Cambridge Computer
+ * Laboratory as part of the CHERI for Hypervisors and Operating Systems
+ * (CHaOS) project, funded by EPSRC grant EP/V000292/1.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer
+ * in this position and unchanged.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/exec.h>
+#include <sys/imgact.h>
+#include <sys/imgact_elf.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/procfs.h>
+#include <sys/ptrace.h>
+#include <sys/sbuf.h>
+#include <sys/sysent.h>
+#include <sys/user.h>
+#include <sys/vnode.h>
+
+#include <machine/elf.h>
+
+#if __ELF_WORD_SIZE == 32
+#define linux_pt_regset linux_pt_regset32
+#define bsd_to_linux_regset bsd_to_linux_regset32
+#include <machine/../linux32/linux.h>
+#else
+#include <machine/../linux/linux.h>
+#endif
+#include <compat/linux/linux_elf.h>
+#include <compat/linux/linux_emul.h>
+#include <compat/linux/linux_misc.h>
+
+/* This adds "linux32_" and "linux64_" prefixes. */
+#define __linuxN(x) __CONCAT(__CONCAT(__CONCAT(linux,__ELF_WORD_SIZE),_),x)
+
+#define LINUX_NT_AUXV 6
+
+static void __linuxN(note_fpregset)(void *, struct sbuf *, size_t *);
+static void __linuxN(note_prpsinfo)(void *, struct sbuf *, size_t *);
+static void __linuxN(note_prstatus)(void *, struct sbuf *, size_t *);
+static void __linuxN(note_threadmd)(void *, struct sbuf *, size_t *);
+static void __linuxN(note_nt_auxv)(void *, struct sbuf *, size_t *);
+
+void
+__linuxN(prepare_notes)(struct thread *td, struct note_info_list *list,
+ size_t *sizep)
+{
+ struct proc *p;
+ struct thread *thr;
+ size_t size;
+
+ p = td->td_proc;
+ size = 0;
+
+ /*
+ * To have the debugger select the right thread (LWP) as the initial
+ * thread, we dump the state of the thread passed to us in td first.
+ * This is the thread that causes the core dump and thus likely to
+ * be the right thread one wants to have selected in the debugger.
+ */
+ thr = td;
+ while (thr != NULL) {
+ size += __elfN(register_note)(td, list,
+ NT_PRSTATUS, __linuxN(note_prstatus), thr);
+ size += __elfN(register_note)(td, list,
+ NT_PRPSINFO, __linuxN(note_prpsinfo), p);
+ size += __elfN(register_note)(td, list,
+ LINUX_NT_AUXV, __linuxN(note_nt_auxv), p);
+ size += __elfN(register_note)(td, list,
+ NT_FPREGSET, __linuxN(note_fpregset), thr);
+ size += __elfN(register_note)(td, list,
+ -1, __linuxN(note_threadmd), thr);
+
+ thr = thr == td ? TAILQ_FIRST(&p->p_threads) :
+ TAILQ_NEXT(thr, td_plist);
+ if (thr == td)
+ thr = TAILQ_NEXT(thr, td_plist);
+ }
+
+ *sizep = size;
+}
+
+typedef struct linux_elf_prstatus linux_elf_prstatus_t;
+#if __ELF_WORD_SIZE == 32
+typedef struct prpsinfo32 linux_elf_prpsinfo_t;
+typedef struct fpreg32 linux_elf_prfpregset_t;
+#else
+typedef prpsinfo_t linux_elf_prpsinfo_t;
+typedef prfpregset_t linux_elf_prfpregset_t;
+#endif
+
+static void
+__linuxN(note_prpsinfo)(void *arg, struct sbuf *sb, size_t *sizep)
+{
+ struct sbuf sbarg;
+ size_t len;
+ char *cp, *end;
+ struct proc *p;
+ linux_elf_prpsinfo_t *psinfo;
+ int error;
+
+ p = arg;
+ if (sb != NULL) {
+ KASSERT(*sizep == sizeof(*psinfo), ("invalid size"));
+ psinfo = malloc(sizeof(*psinfo), M_TEMP, M_ZERO | M_WAITOK);
+ psinfo->pr_version = PRPSINFO_VERSION;
+ psinfo->pr_psinfosz = sizeof(linux_elf_prpsinfo_t);
+ strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
+ PROC_LOCK(p);
+ if (p->p_args != NULL) {
+ len = sizeof(psinfo->pr_psargs) - 1;
+ if (len > p->p_args->ar_length)
+ len = p->p_args->ar_length;
+ memcpy(psinfo->pr_psargs, p->p_args->ar_args, len);
+ PROC_UNLOCK(p);
+ error = 0;
+ } else {
+ _PHOLD(p);
+ PROC_UNLOCK(p);
+ sbuf_new(&sbarg, psinfo->pr_psargs,
+ sizeof(psinfo->pr_psargs), SBUF_FIXEDLEN);
+ error = proc_getargv(curthread, p, &sbarg);
+ PRELE(p);
+ if (sbuf_finish(&sbarg) == 0)
+ len = sbuf_len(&sbarg) - 1;
+ else
+ len = sizeof(psinfo->pr_psargs) - 1;
+ sbuf_delete(&sbarg);
+ }
+ if (error || len == 0)
+ strlcpy(psinfo->pr_psargs, p->p_comm,
+ sizeof(psinfo->pr_psargs));
+ else {
+ KASSERT(len < sizeof(psinfo->pr_psargs),
+ ("len is too long: %zu vs %zu", len,
+ sizeof(psinfo->pr_psargs)));
+ cp = psinfo->pr_psargs;
+ end = cp + len - 1;
+ for (;;) {
+ cp = memchr(cp, '\0', end - cp);
+ if (cp == NULL)
+ break;
+ *cp = ' ';
+ }
+ }
+ psinfo->pr_pid = p->p_pid;
+ sbuf_bcat(sb, psinfo, sizeof(*psinfo));
+ free(psinfo, M_TEMP);
+ }
+ *sizep = sizeof(*psinfo);
+}
+
+static void
+__linuxN(note_prstatus)(void *arg, struct sbuf *sb, size_t *sizep)
+{
+ struct thread *td;
+ linux_elf_prstatus_t *status;
+#if __ELF_WORD_SIZE == 32
+ struct reg32 pr_reg;
+#else
+ struct reg pr_reg;
+#endif
+
+ td = arg;
+ if (sb != NULL) {
+ KASSERT(*sizep == sizeof(*status), ("invalid size"));
+ status = malloc(sizeof(*status), M_TEMP, M_ZERO | M_WAITOK);
+
+ /*
+ * XXX: Some fields missing.
+ */
+ status->pr_cursig = td->td_proc->p_sig;
+ status->pr_pid = td->td_tid;
+
+#if __ELF_WORD_SIZE == 32
+ fill_regs32(td, &pr_reg);
+#else
+ fill_regs(td, &pr_reg);
+#endif
+ bsd_to_linux_regset(&pr_reg, &status->pr_reg);
+ sbuf_bcat(sb, status, sizeof(*status));
+ free(status, M_TEMP);
+ }
+ *sizep = sizeof(*status);
+}
+
+static void
+__linuxN(note_fpregset)(void *arg, struct sbuf *sb, size_t *sizep)
+{
+ struct thread *td;
+ linux_elf_prfpregset_t *fpregset;
+
+ td = arg;
+ if (sb != NULL) {
+ KASSERT(*sizep == sizeof(*fpregset), ("invalid size"));
+ fpregset = malloc(sizeof(*fpregset), M_TEMP, M_ZERO | M_WAITOK);
+#if __ELF_WORD_SIZE == 32
+ fill_fpregs32(td, fpregset);
+#else
+ fill_fpregs(td, fpregset);
+#endif
+ sbuf_bcat(sb, fpregset, sizeof(*fpregset));
+ free(fpregset, M_TEMP);
+ }
+ *sizep = sizeof(*fpregset);
+}
+
+/*
+ * Allow for MD specific notes, as well as any MD
+ * specific preparations for writing MI notes.
+ */
+static void
+__linuxN(note_threadmd)(void *arg, struct sbuf *sb, size_t *sizep)
+{
+ struct thread *td;
+ void *buf;
+ size_t size;
+
+ td = arg;
+ size = *sizep;
+ if (size != 0 && sb != NULL)
+ buf = malloc(size, M_TEMP, M_ZERO | M_WAITOK);
+ else
+ buf = NULL;
+ size = 0;
+ __elfN(dump_thread)(td, buf, &size);
+ KASSERT(sb == NULL || *sizep == size, ("invalid size"));
+ if (size != 0 && sb != NULL)
+ sbuf_bcat(sb, buf, size);
+ free(buf, M_TEMP);
+ *sizep = size;
+}
+
+static void
+__linuxN(note_nt_auxv)(void *arg, struct sbuf *sb, size_t *sizep)
+{
+ struct proc *p;
+ size_t size;
+
+ p = arg;
+ if (sb == NULL) {
+ size = 0;
+ sb = sbuf_new(NULL, NULL, LINUX_AT_COUNT * sizeof(Elf_Auxinfo),
+ SBUF_FIXEDLEN);
+ sbuf_set_drain(sb, sbuf_count_drain, &size);
+ PHOLD(p);
+ proc_getauxv(curthread, p, sb);
+ PRELE(p);
+ sbuf_finish(sb);
+ sbuf_delete(sb);
+ *sizep = size;
+ } else {
+ PHOLD(p);
+ proc_getauxv(curthread, p, sb);
+ PRELE(p);
+ }
+}
diff --git a/sys/compat/linux/linux_elf.h b/sys/compat/linux/linux_elf.h
new file mode 100644
index 000000000000..4bb9318e360b
--- /dev/null
+++ b/sys/compat/linux/linux_elf.h
@@ -0,0 +1,56 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2018 Chuck Tuffli
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _COMPAT_LINUX_ELF_H_
+#define _COMPAT_LINUX_ELF_H_
+
+struct l_elf_siginfo {
+ l_int si_signo;
+ l_int si_code;
+ l_int si_errno;
+};
+
+typedef struct linux_pt_regset l_elf_gregset_t;
+
+struct linux_elf_prstatus {
+ struct l_elf_siginfo pr_info;
+ l_short pr_cursig;
+ l_ulong pr_sigpend;
+ l_ulong pr_sighold;
+ l_pid_t pr_pid;
+ l_pid_t pr_ppid;
+ l_pid_t pr_pgrp;
+ l_pid_t pr_sid;
+ l_timeval pr_utime;
+ l_timeval pr_stime;
+ l_timeval pr_cutime;
+ l_timeval pr_cstime;
+ l_elf_gregset_t pr_reg;
+ l_int pr_fpvalid;
+};
+
+#endif
diff --git a/sys/compat/linux/linux_elf32.c b/sys/compat/linux/linux_elf32.c
new file mode 100644
index 000000000000..17ee4b6baa0a
--- /dev/null
+++ b/sys/compat/linux/linux_elf32.c
@@ -0,0 +1,38 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Edward Tomasz Napierala <trasz@FreeBSD.org>
+ * Copyright (c) 2002 Doug Rabson
+ * All rights reserved.
+ *
+ * This software was developed by the University of Cambridge Computer
+ * Laboratory as part of the CHERI for Hypervisors and Operating Systems
+ * (CHaOS) project, funded by EPSRC grant EP/V000292/1.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#define __ELF_WORD_SIZE 32
+#include <compat/linux/linux_elf.c>
diff --git a/sys/compat/linux/linux_elf64.c b/sys/compat/linux/linux_elf64.c
new file mode 100644
index 000000000000..2e283d763bbc
--- /dev/null
+++ b/sys/compat/linux/linux_elf64.c
@@ -0,0 +1,38 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2021 Edward Tomasz Napierala <trasz@FreeBSD.org>
+ * Copyright (c) 2002 Doug Rabson
+ * All rights reserved.
+ *
+ * This software was developed by the University of Cambridge Computer
+ * Laboratory as part of the CHERI for Hypervisors and Operating Systems
+ * (CHaOS) project, funded by EPSRC grant EP/V000292/1.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#define __ELF_WORD_SIZE 64
+#include <compat/linux/linux_elf.c>
diff --git a/sys/compat/linux/linux_emul.h b/sys/compat/linux/linux_emul.h
index de66a7a4c82a..d5f37c918b6c 100644
--- a/sys/compat/linux/linux_emul.h
+++ b/sys/compat/linux/linux_emul.h
@@ -33,6 +33,10 @@
#define _LINUX_EMUL_H_
struct image_params;
+struct note_info_list;
+
+/* Linux core notes are labeled "CORE" */
+#define LINUX_ABI_VENDOR "CORE"
/*
* modeled after similar structure in NetBSD
@@ -58,6 +62,8 @@ void linux_on_exec(struct proc *, struct image_params *);
void linux_thread_dtor(struct thread *);
void linux_thread_detach(struct thread *);
int linux_common_execve(struct thread *, struct image_args *);
+void linux32_prepare_notes(struct thread *, struct note_info_list *, size_t *);
+void linux64_prepare_notes(struct thread *, struct note_info_list *, size_t *);
/* process emuldata flags */
#define LINUX_XDEPR_REQUEUEOP 0x00000001 /* uses deprecated
diff --git a/sys/modules/linux/Makefile b/sys/modules/linux/Makefile
index fd027e2118df..4f12c4dc6913 100644
--- a/sys/modules/linux/Makefile
+++ b/sys/modules/linux/Makefile
@@ -26,6 +26,7 @@ SRCS+= linux_dummy_x86.c
.endif
.if ${MACHINE_CPUARCH} == "amd64"
SRCS+= linux${SFX}_support.s
+SRCS+= linux_elf32.c
.else
SRCS+= linux_copyout.c
.endif
diff --git a/sys/modules/linux64/Makefile b/sys/modules/linux64/Makefile
index 994f4aff1dac..c269a2251b76 100644
--- a/sys/modules/linux64/Makefile
+++ b/sys/modules/linux64/Makefile
@@ -18,6 +18,7 @@ SRCS= linux_fork.c linux_dummy_machdep.c linux_file.c linux_event.c \
linux_support.s
.if ${MACHINE_CPUARCH} == "amd64"
SRCS+= linux_dummy_x86.c
+SRCS+= linux_elf64.c
.endif
DPSRCS= assym.inc linux_genassym.c