elf core dump: notes user_regset
This modifies the ELF core dump code under #ifdef CORE_DUMP_USE_REGSET. It changes nothing when this macro is not defined. When it's #define'd by some arch header (e.g. asm/elf.h), the arch must support the user_regset (linux/regset.h) interface for reading thread state. This provides an alternate version of note segment writing that is based purely on the user_regset interfaces. When CORE_DUMP_USE_REGSET is set, the arch need not define macros such as ELF_CORE_COPY_REGS and ELF_ARCH. All that information is taken from the user_regset data structures. The core dumps come out exactly the same if arch's definitions for its user_regset details are correct. Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Roland McGrath
Ingo Molnar
parent
3aba481fc9
commit
4206d3aa19
224
fs/binfmt_elf.c
224
fs/binfmt_elf.c
@ -1528,6 +1528,228 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
|
||||
fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
|
||||
}
|
||||
|
||||
#ifdef CORE_DUMP_USE_REGSET
|
||||
#include <linux/regset.h>
|
||||
|
||||
struct elf_thread_core_info {
|
||||
struct elf_thread_core_info *next;
|
||||
struct task_struct *task;
|
||||
struct elf_prstatus prstatus;
|
||||
struct memelfnote notes[0];
|
||||
};
|
||||
|
||||
struct elf_note_info {
|
||||
struct elf_thread_core_info *thread;
|
||||
struct memelfnote psinfo;
|
||||
struct memelfnote auxv;
|
||||
size_t size;
|
||||
int thread_notes;
|
||||
};
|
||||
|
||||
static int fill_thread_core_info(struct elf_thread_core_info *t,
|
||||
const struct user_regset_view *view,
|
||||
long signr, size_t *total)
|
||||
{
|
||||
unsigned int i;
|
||||
|
||||
/*
|
||||
* NT_PRSTATUS is the one special case, because the regset data
|
||||
* goes into the pr_reg field inside the note contents, rather
|
||||
* than being the whole note contents. We fill the reset in here.
|
||||
* We assume that regset 0 is NT_PRSTATUS.
|
||||
*/
|
||||
fill_prstatus(&t->prstatus, t->task, signr);
|
||||
(void) view->regsets[0].get(t->task, &view->regsets[0],
|
||||
0, sizeof(t->prstatus.pr_reg),
|
||||
&t->prstatus.pr_reg, NULL);
|
||||
|
||||
fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
|
||||
sizeof(t->prstatus), &t->prstatus);
|
||||
*total += notesize(&t->notes[0]);
|
||||
|
||||
/*
|
||||
* Each other regset might generate a note too. For each regset
|
||||
* that has no core_note_type or is inactive, we leave t->notes[i]
|
||||
* all zero and we'll know to skip writing it later.
|
||||
*/
|
||||
for (i = 1; i < view->n; ++i) {
|
||||
const struct user_regset *regset = &view->regsets[i];
|
||||
if (regset->core_note_type &&
|
||||
(!regset->active || regset->active(t->task, regset))) {
|
||||
int ret;
|
||||
size_t size = regset->n * regset->size;
|
||||
void *data = kmalloc(size, GFP_KERNEL);
|
||||
if (unlikely(!data))
|
||||
return 0;
|
||||
ret = regset->get(t->task, regset,
|
||||
0, size, data, NULL);
|
||||
if (unlikely(ret))
|
||||
kfree(data);
|
||||
else {
|
||||
if (regset->core_note_type != NT_PRFPREG)
|
||||
fill_note(&t->notes[i], "LINUX",
|
||||
regset->core_note_type,
|
||||
size, data);
|
||||
else {
|
||||
t->prstatus.pr_fpvalid = 1;
|
||||
fill_note(&t->notes[i], "CORE",
|
||||
NT_PRFPREG, size, data);
|
||||
}
|
||||
*total += notesize(&t->notes[i]);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static int fill_note_info(struct elfhdr *elf, int phdrs,
|
||||
struct elf_note_info *info,
|
||||
long signr, struct pt_regs *regs)
|
||||
{
|
||||
struct task_struct *dump_task = current;
|
||||
const struct user_regset_view *view = task_user_regset_view(dump_task);
|
||||
struct elf_thread_core_info *t;
|
||||
struct elf_prpsinfo *psinfo;
|
||||
struct task_struct *g, *p;
|
||||
unsigned int i;
|
||||
|
||||
info->size = 0;
|
||||
info->thread = NULL;
|
||||
|
||||
psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
|
||||
fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
|
||||
|
||||
if (psinfo == NULL)
|
||||
return 0;
|
||||
|
||||
/*
|
||||
* Figure out how many notes we're going to need for each thread.
|
||||
*/
|
||||
info->thread_notes = 0;
|
||||
for (i = 0; i < view->n; ++i)
|
||||
if (view->regsets[i].core_note_type != 0)
|
||||
++info->thread_notes;
|
||||
|
||||
/*
|
||||
* Sanity check. We rely on regset 0 being in NT_PRSTATUS,
|
||||
* since it is our one special case.
|
||||
*/
|
||||
if (unlikely(info->thread_notes == 0) ||
|
||||
unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
|
||||
WARN_ON(1);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Initialize the ELF file header.
|
||||
*/
|
||||
fill_elf_header(elf, phdrs,
|
||||
view->e_machine, view->e_flags, view->ei_osabi);
|
||||
|
||||
/*
|
||||
* Allocate a structure for each thread.
|
||||
*/
|
||||
rcu_read_lock();
|
||||
do_each_thread(g, p)
|
||||
if (p->mm == dump_task->mm) {
|
||||
t = kzalloc(offsetof(struct elf_thread_core_info,
|
||||
notes[info->thread_notes]),
|
||||
GFP_ATOMIC);
|
||||
if (unlikely(!t)) {
|
||||
rcu_read_unlock();
|
||||
return 0;
|
||||
}
|
||||
t->task = p;
|
||||
if (p == dump_task || !info->thread) {
|
||||
t->next = info->thread;
|
||||
info->thread = t;
|
||||
} else {
|
||||
/*
|
||||
* Make sure to keep the original task at
|
||||
* the head of the list.
|
||||
*/
|
||||
t->next = info->thread->next;
|
||||
info->thread->next = t;
|
||||
}
|
||||
}
|
||||
while_each_thread(g, p);
|
||||
rcu_read_unlock();
|
||||
|
||||
/*
|
||||
* Now fill in each thread's information.
|
||||
*/
|
||||
for (t = info->thread; t != NULL; t = t->next)
|
||||
if (!fill_thread_core_info(t, view, signr, &info->size))
|
||||
return 0;
|
||||
|
||||
/*
|
||||
* Fill in the two process-wide notes.
|
||||
*/
|
||||
fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
|
||||
info->size += notesize(&info->psinfo);
|
||||
|
||||
fill_auxv_note(&info->auxv, current->mm);
|
||||
info->size += notesize(&info->auxv);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static size_t get_note_info_size(struct elf_note_info *info)
|
||||
{
|
||||
return info->size;
|
||||
}
|
||||
|
||||
/*
|
||||
* Write all the notes for each thread. When writing the first thread, the
|
||||
* process-wide notes are interleaved after the first thread-specific note.
|
||||
*/
|
||||
static int write_note_info(struct elf_note_info *info,
|
||||
struct file *file, loff_t *foffset)
|
||||
{
|
||||
bool first = 1;
|
||||
struct elf_thread_core_info *t = info->thread;
|
||||
|
||||
do {
|
||||
int i;
|
||||
|
||||
if (!writenote(&t->notes[0], file, foffset))
|
||||
return 0;
|
||||
|
||||
if (first && !writenote(&info->psinfo, file, foffset))
|
||||
return 0;
|
||||
if (first && !writenote(&info->auxv, file, foffset))
|
||||
return 0;
|
||||
|
||||
for (i = 1; i < info->thread_notes; ++i)
|
||||
if (t->notes[i].data &&
|
||||
!writenote(&t->notes[i], file, foffset))
|
||||
return 0;
|
||||
|
||||
first = 0;
|
||||
t = t->next;
|
||||
} while (t);
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static void free_note_info(struct elf_note_info *info)
|
||||
{
|
||||
struct elf_thread_core_info *threads = info->thread;
|
||||
while (threads) {
|
||||
unsigned int i;
|
||||
struct elf_thread_core_info *t = threads;
|
||||
threads = t->next;
|
||||
WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
|
||||
for (i = 1; i < info->thread_notes; ++i)
|
||||
kfree(t->notes[i].data);
|
||||
kfree(t);
|
||||
}
|
||||
kfree(info->psinfo.data);
|
||||
}
|
||||
|
||||
#else
|
||||
|
||||
/* Here is the structure in which status of each thread is captured. */
|
||||
struct elf_thread_status
|
||||
{
|
||||
@ -1748,6 +1970,8 @@ static void free_note_info(struct elf_note_info *info)
|
||||
#endif
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
static struct vm_area_struct *first_vma(struct task_struct *tsk,
|
||||
struct vm_area_struct *gate_vma)
|
||||
{
|
||||
|
||||
Loading…
Reference in New Issue
Block a user