From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file

---
 kernel/kernel/crash_core.c |   58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/kernel/kernel/crash_core.c b/kernel/kernel/crash_core.c
index 933cb3e..4a5fed2 100644
--- a/kernel/kernel/crash_core.c
+++ b/kernel/kernel/crash_core.c
@@ -1,9 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * crash.c - kernel crash support code.
  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
- *
- * This source code is licensed under the GNU General Public License,
- * Version 2.  See the file COPYING for more details.
  */
 
 #include <linux/crash_core.h>
@@ -12,6 +10,8 @@
 
 #include <asm/page.h>
 #include <asm/sections.h>
+
+#include <crypto/sha.h>
 
 /* vmcoreinfo stuff */
 unsigned char *vmcoreinfo_data;
@@ -378,6 +378,53 @@
 }
 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 
+#define NOTES_SIZE (&__stop_notes - &__start_notes)
+#define BUILD_ID_MAX SHA1_DIGEST_SIZE
+#define NT_GNU_BUILD_ID 3
+
+struct elf_note_section {
+	struct elf_note	n_hdr;
+	u8 n_data[];
+};
+
+/*
+ * Add build ID from .notes section as generated by the GNU ld(1)
+ * or LLVM lld(1) --build-id option.
+ */
+static void add_build_id_vmcoreinfo(void)
+{
+	char build_id[BUILD_ID_MAX * 2 + 1];
+	int n_remain = NOTES_SIZE;
+
+	while (n_remain >= sizeof(struct elf_note)) {
+		const struct elf_note_section *note_sec =
+			&__start_notes + NOTES_SIZE - n_remain;
+		const u32 n_namesz = note_sec->n_hdr.n_namesz;
+
+		if (note_sec->n_hdr.n_type == NT_GNU_BUILD_ID &&
+		    n_namesz != 0 &&
+		    !strcmp((char *)&note_sec->n_data[0], "GNU")) {
+			if (note_sec->n_hdr.n_descsz <= BUILD_ID_MAX) {
+				const u32 n_descsz = note_sec->n_hdr.n_descsz;
+				const u8 *s = &note_sec->n_data[n_namesz];
+
+				s = PTR_ALIGN(s, 4);
+				bin2hex(build_id, s, n_descsz);
+				build_id[2 * n_descsz] = '\0';
+				VMCOREINFO_BUILD_ID(build_id);
+				return;
+			}
+			pr_warn("Build ID is too large to include in vmcoreinfo: %u > %u\n",
+				note_sec->n_hdr.n_descsz,
+				BUILD_ID_MAX);
+			return;
+		}
+		n_remain -= sizeof(struct elf_note) +
+			ALIGN(note_sec->n_hdr.n_namesz, 4) +
+			ALIGN(note_sec->n_hdr.n_descsz, 4);
+	}
+}
+
 static int __init crash_save_vmcoreinfo_init(void)
 {
 	vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
@@ -396,6 +443,7 @@
 	}
 
 	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
+	add_build_id_vmcoreinfo();
 	VMCOREINFO_PAGESIZE(PAGE_SIZE);
 
 	VMCOREINFO_SYMBOL(init_uts_ns);
@@ -415,6 +463,8 @@
 	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 	VMCOREINFO_STRUCT_SIZE(mem_section);
 	VMCOREINFO_OFFSET(mem_section, section_mem_map);
+	VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
+	VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
 #endif
 	VMCOREINFO_STRUCT_SIZE(page);
 	VMCOREINFO_STRUCT_SIZE(pglist_data);
@@ -464,6 +514,8 @@
 	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 #ifdef CONFIG_HUGETLB_PAGE
 	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
+#define PAGE_OFFLINE_MAPCOUNT_VALUE	(~PG_offline)
+	VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
 #endif
 
 	arch_crash_save_vmcoreinfo();

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