The patch titled
Subject: coredump: add a new elf note with siginfo of the signal
has been added to the -mm tree. Its filename is
coredump-add-a-new-elf-note-with-siginfo-of-the-signal.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Denys Vlasenko <vda.linux@xxxxxxxxxxxxxx>
Subject: coredump: add a new elf note with siginfo of the signal
Existing PRSTATUS note contains only si_signo, si_code, si_errno fields
from the siginfo of the signal which caused core to be dumped.
There are tools which try to analyze crashes for possible security
implications, and they want to use, among other data, si_addr field from
the SIGSEGV.
This patch adds a new elf note, NT_SIGINFO, which contains the complete
siginfo_t of the signal which killed the process.
Signed-off-by: Denys Vlasenko <vda.linux@xxxxxxxxxxxxxx>
Reviewed-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Amerigo Wang <amwang@xxxxxxxxxx>
Cc: "Jonathan M. Foote" <jmfoote@xxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxxxxx>
Cc: Pedro Alves <palves@xxxxxxxxxx>
Cc: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_elf.c | 27 +++++++++++++++++++++++++--
fs/compat_binfmt_elf.c | 6 ++++++
include/linux/elf.h | 5 +++++
3 files changed, 36 insertions(+), 2 deletions(-)
diff -puN fs/binfmt_elf.c~coredump-add-a-new-elf-note-with-siginfo-of-the-signal fs/binfmt_elf.c
--- a/fs/binfmt_elf.c~coredump-add-a-new-elf-note-with-siginfo-of-the-signal
+++ a/fs/binfmt_elf.c
@@ -36,6 +36,10 @@
#include <asm/param.h>
#include <asm/page.h>
+#ifndef user_siginfo_t
+#define user_siginfo_t siginfo_t
+#endif
+
static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
static int load_elf_library(struct file *);
static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
@@ -1371,6 +1375,16 @@ static void fill_auxv_note(struct memelf
fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
}
+static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
+ siginfo_t *siginfo)
+{
+ mm_segment_t old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
+ set_fs(old_fs);
+ fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
+}
+
#ifdef CORE_DUMP_USE_REGSET
#include <linux/regset.h>
@@ -1384,7 +1398,9 @@ struct elf_thread_core_info {
struct elf_note_info {
struct elf_thread_core_info *thread;
struct memelfnote psinfo;
+ struct memelfnote signote;
struct memelfnote auxv;
+ user_siginfo_t csigdata;
size_t size;
int thread_notes;
};
@@ -1558,6 +1574,9 @@ static int fill_note_info(struct elfhdr
fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
info->size += notesize(&info->psinfo);
+ fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
+ info->size += notesize(&info->signote);
+
fill_auxv_note(&info->auxv, current->mm);
info->size += notesize(&info->auxv);
@@ -1587,6 +1606,8 @@ static int write_note_info(struct elf_no
if (first && !writenote(&info->psinfo, file, foffset))
return 0;
+ if (first && !writenote(&info->signote, file, foffset))
+ return 0;
if (first && !writenote(&info->auxv, file, foffset))
return 0;
@@ -1680,6 +1701,7 @@ struct elf_note_info {
#ifdef ELF_CORE_COPY_XFPREGS
elf_fpxregset_t *xfpu;
#endif
+ user_siginfo_t csigdata;
int thread_status_size;
int numnote;
};
@@ -1689,8 +1711,8 @@ static int elf_note_info_init(struct elf
memset(info, 0, sizeof(*info));
INIT_LIST_HEAD(&info->thread_list);
- /* Allocate space for six ELF notes */
- info->notes = kmalloc(6 * sizeof(struct memelfnote), GFP_KERNEL);
+ /* Allocate space for ELF notes */
+ info->notes = kmalloc(7 * sizeof(struct memelfnote), GFP_KERNEL);
if (!info->notes)
return 0;
info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
@@ -1762,6 +1784,7 @@ static int fill_note_info(struct elfhdr
info->numnote = 2;
+ fill_siginfo_note(&info->notes[info->numnote++], &info->csigdata, siginfo);
fill_auxv_note(&info->notes[info->numnote++], current->mm);
/* Try to dump the FPU. */
diff -puN fs/compat_binfmt_elf.c~coredump-add-a-new-elf-note-with-siginfo-of-the-signal fs/compat_binfmt_elf.c
--- a/fs/compat_binfmt_elf.c~coredump-add-a-new-elf-note-with-siginfo-of-the-signal
+++ a/fs/compat_binfmt_elf.c
@@ -38,6 +38,12 @@
#define elf_addr_t Elf32_Addr
/*
+ * Some data types as stored in coredump.
+ */
+#define user_siginfo_t compat_siginfo_t
+#define copy_siginfo_to_user copy_siginfo_to_user32
+
+/*
* The machine-dependent core note format types are defined in elfcore-compat.h,
* which requires asm/elf.h to define compat_elf_gregset_t et al.
*/
diff -puN include/linux/elf.h~coredump-add-a-new-elf-note-with-siginfo-of-the-signal include/linux/elf.h
--- a/include/linux/elf.h~coredump-add-a-new-elf-note-with-siginfo-of-the-signal
+++ a/include/linux/elf.h
@@ -372,6 +372,11 @@ typedef struct elf64_shdr {
#define NT_PRPSINFO 3
#define NT_TASKSTRUCT 4
#define NT_AUXV 6
+/*
+ * Note to userspace developers: size of NT_SIGINFO note may increase
+ * in the future to accomodate more fields, don't assume it is fixed!
+ */
+#define NT_SIGINFO 0x53494749
#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 */
_
Patches currently in -mm which might be from vda.linux@xxxxxxxxxxxxxx are
lib-vsprintf-optimize-division-by-10-for-small-integers.patch
lib-vsprintf-optimize-division-by-10000.patch
lib-vsprintf-optimize-put_dec_trunc8.patch
lib-vsprintf-fix-broken-comments.patch
coredump-prevent-double-free-on-an-error-path-in-core-dumper.patch
coredump-add-support-for-%d=__get_dumpable-in-core-name.patch
coredump-pass-siginfo_t-to-do_coredump-and-below-not-merely-signr.patch
compat-move-compat_siginfo_t-definition-to-asm-compath.patch
coredump-add-a-new-elf-note-with-siginfo-of-the-signal.patch
coredump-extend-core-dump-note-section-to-contain-file-names-of-mapped-files.patch
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