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Commit 2aa362c4 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Linus Torvalds
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coredump: extend core dump note section to contain file names of mapped files



This note has the following format:

long count     -- how many files are mapped
long page_size -- units for file_ofs
array of [COUNT] elements of
   long start
   long end
   long file_ofs
followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...

Signed-off-by: default avatarDenys Vlasenko <vda.linux@googlemail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: "Jonathan M. Foote" <jmfoote@cert.org>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 49ae4d4b
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+106 −4
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@
#include <linux/compiler.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#include <linux/security.h>
#include <linux/random.h>
#include <linux/elf.h>
@@ -37,6 +38,9 @@
#include <asm/page.h>
#include <asm/exec.h>

#ifndef user_long_t
#define user_long_t long
#endif
#ifndef user_siginfo_t
#define user_siginfo_t siginfo_t
#endif
@@ -1386,6 +1390,93 @@ static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
	fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
}

#define MAX_FILE_NOTE_SIZE (4*1024*1024)
/*
 * Format of NT_FILE note:
 *
 * long count     -- how many files are mapped
 * long page_size -- units for file_ofs
 * array of [COUNT] elements of
 *   long start
 *   long end
 *   long file_ofs
 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
 */
static void fill_files_note(struct memelfnote *note)
{
	struct vm_area_struct *vma;
	unsigned count, size, names_ofs, remaining, n;
	user_long_t *data;
	user_long_t *start_end_ofs;
	char *name_base, *name_curpos;

	/* *Estimated* file count and total data size needed */
	count = current->mm->map_count;
	size = count * 64;

	names_ofs = (2 + 3 * count) * sizeof(data[0]);
 alloc:
	if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
		goto err;
	size = round_up(size, PAGE_SIZE);
	data = vmalloc(size);
	if (!data)
		goto err;

	start_end_ofs = data + 2;
	name_base = name_curpos = ((char *)data) + names_ofs;
	remaining = size - names_ofs;
	count = 0;
	for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
		struct file *file;
		const char *filename;

		file = vma->vm_file;
		if (!file)
			continue;
		filename = d_path(&file->f_path, name_curpos, remaining);
		if (IS_ERR(filename)) {
			if (PTR_ERR(filename) == -ENAMETOOLONG) {
				vfree(data);
				size = size * 5 / 4;
				goto alloc;
			}
			continue;
		}

		/* d_path() fills at the end, move name down */
		/* n = strlen(filename) + 1: */
		n = (name_curpos + remaining) - filename;
		remaining = filename - name_curpos;
		memmove(name_curpos, filename, n);
		name_curpos += n;

		*start_end_ofs++ = vma->vm_start;
		*start_end_ofs++ = vma->vm_end;
		*start_end_ofs++ = vma->vm_pgoff;
		count++;
	}

	/* Now we know exact count of files, can store it */
	data[0] = count;
	data[1] = PAGE_SIZE;
	/*
	 * Count usually is less than current->mm->map_count,
	 * we need to move filenames down.
	 */
	n = current->mm->map_count - count;
	if (n != 0) {
		unsigned shift_bytes = n * 3 * sizeof(data[0]);
		memmove(name_base - shift_bytes, name_base,
			name_curpos - name_base);
		name_curpos -= shift_bytes;
	}

	size = name_curpos - (char *)data;
	fill_note(note, "CORE", NT_FILE, size, data);
 err: ;
}

#ifdef CORE_DUMP_USE_REGSET
#include <linux/regset.h>

@@ -1401,6 +1492,7 @@ struct elf_note_info {
	struct memelfnote psinfo;
	struct memelfnote signote;
	struct memelfnote auxv;
	struct memelfnote files;
	user_siginfo_t csigdata;
	size_t size;
	int thread_notes;
@@ -1581,6 +1673,9 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
	fill_auxv_note(&info->auxv, current->mm);
	info->size += notesize(&info->auxv);

	fill_files_note(&info->files);
	info->size += notesize(&info->files);

	return 1;
}

@@ -1611,6 +1706,8 @@ static int write_note_info(struct elf_note_info *info,
			return 0;
		if (first && !writenote(&info->auxv, file, foffset))
			return 0;
		if (first && !writenote(&info->files, file, foffset))
			return 0;

		for (i = 1; i < info->thread_notes; ++i)
			if (t->notes[i].data &&
@@ -1637,6 +1734,7 @@ static void free_note_info(struct elf_note_info *info)
		kfree(t);
	}
	kfree(info->psinfo.data);
	vfree(info->files.data);
}

#else
@@ -1713,7 +1811,7 @@ static int elf_note_info_init(struct elf_note_info *info)
	INIT_LIST_HEAD(&info->thread_list);

	/* Allocate space for ELF notes */
	info->notes = kmalloc(7 * sizeof(struct memelfnote), GFP_KERNEL);
	info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
	if (!info->notes)
		return 0;
	info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
@@ -1783,10 +1881,11 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
	fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
		  sizeof(*info->psinfo), info->psinfo);

	info->numnote = 2;
	fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
	fill_auxv_note(info->notes + 3, current->mm);
	fill_files_note(info->notes + 4);

	fill_siginfo_note(&info->notes[info->numnote++], &info->csigdata, siginfo);
	fill_auxv_note(&info->notes[info->numnote++], current->mm);
	info->numnote = 5;

	/* Try to dump the FPU. */
	info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
@@ -1848,6 +1947,9 @@ static void free_note_info(struct elf_note_info *info)
		kfree(list_entry(tmp, struct elf_thread_status, list));
	}

	/* Free data allocated by fill_files_note(): */
	vfree(info->notes[4].data);

	kfree(info->prstatus);
	kfree(info->psinfo);
	kfree(info->notes);
+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@
/*
 * Some data types as stored in coredump.
 */
#define user_long_t		compat_long_t
#define user_siginfo_t		compat_siginfo_t
#define copy_siginfo_to_user	copy_siginfo_to_user32

+1 −0
Original line number Diff line number Diff line
@@ -377,6 +377,7 @@ typedef struct elf64_shdr {
 * in the future to accomodate more fields, don't assume it is fixed!
 */
#define NT_SIGINFO      0x53494749
#define NT_FILE         0x46494c45
#define NT_PRXFPREG     0x46e62b7f      /* copied from gdb5.1/include/elf/common.h */
#define NT_PPC_VMX	0x100		/* PowerPC Altivec/VMX registers */
#define NT_PPC_SPE	0x101		/* PowerPC SPE/EVR registers */