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authorRoland McGrath <roland@redhat.com>2008-01-30 13:31:45 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-30 13:31:45 +0100
commit4206d3aa1978e44f58bfa4e1c9d8d35cbf19c187 (patch)
tree53de158bec7e6890ce9a5772f3d04f23e9a29803 /fs/binfmt_elf.c
parent3aba481fc94d83ff630d4b7cd2f7447010c4c6df (diff)
downloadconfigs-4206d3aa1978e44f58bfa4e1c9d8d35cbf19c187.tar.gz
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>
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c224
1 files changed, 224 insertions, 0 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 4510429b973..786ee275ec0 100644
--- a/fs/binfmt_elf.c
+++ b/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)
{