Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull fdpick coredump update from Al Viro:
 "Switches fdpic coredumps away from original aout dumping primitives to
  the same kind of regset use as regular elf coredumps do"

* 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [elf-fdpic] switch coredump to regsets
  [elf-fdpic] use elf_dump_thread_status() for the dumper thread as well
  [elf-fdpic] move allocation of elf_thread_status into elf_dump_thread_status()
  [elf-fdpic] coredump: don't bother with cyclic list for per-thread objects
  kill elf_fpxregs_t
  take fdpic-related parts of elf_prstatus out
  unexport linux/elfcore.h

1 files changed, 90 insertions, 115 deletions

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index cf306e0798fd..50f845702b92 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -35,6 +35,7 @@
 #include <linux/elfcore.h>
 #include <linux/coredump.h>
 #include <linux/dax.h>
+#include <linux/regset.h>
 
 #include <linux/uaccess.h>
 #include <asm/param.h>
@@ -1188,6 +1189,32 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
  */
 #ifdef CONFIG_ELF_CORE
 
+struct elf_prstatus_fdpic
+{
+	struct elf_siginfo pr_info;	/* Info associated with signal */
+	short	pr_cursig;		/* Current signal */
+	unsigned long pr_sigpend;	/* Set of pending signals */
+	unsigned long pr_sighold;	/* Set of held signals */
+	pid_t	pr_pid;
+	pid_t	pr_ppid;
+	pid_t	pr_pgrp;
+	pid_t	pr_sid;
+	struct __kernel_old_timeval pr_utime;	/* User time */
+	struct __kernel_old_timeval pr_stime;	/* System time */
+	struct __kernel_old_timeval pr_cutime;	/* Cumulative user time */
+	struct __kernel_old_timeval pr_cstime;	/* Cumulative system time */
+	elf_gregset_t pr_reg;	/* GP registers */
+	/* When using FDPIC, the loadmap addresses need to be communicated
+	 * to GDB in order for GDB to do the necessary relocations.  The
+	 * fields (below) used to communicate this information are placed
+	 * immediately after ``pr_reg'', so that the loadmap addresses may
+	 * be viewed as part of the register set if so desired.
+	 */
+	unsigned long pr_exec_fdpic_loadmap;
+	unsigned long pr_interp_fdpic_loadmap;
+	int pr_fpvalid;		/* True if math co-processor being used.  */
+};
+
 /*
  * Decide whether a segment is worth dumping; default is yes to be
  * sure (missing info is worse than too much; etc).
@@ -1344,7 +1371,7 @@ static inline void fill_note(struct memelfnote *note, const char *name, int type
  * fill up all the fields in prstatus from the given task struct, except
  * registers which need to be filled up separately.
  */
-static void fill_prstatus(struct elf_prstatus *prstatus,
+static void fill_prstatus(struct elf_prstatus_fdpic *prstatus,
 			  struct task_struct *p, long signr)
 {
 	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
@@ -1426,14 +1453,10 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
 /* Here is the structure in which status of each thread is captured. */
 struct elf_thread_status
 {
-	struct list_head list;
-	struct elf_prstatus prstatus;	/* NT_PRSTATUS */
+	struct elf_thread_status *next;
+	struct elf_prstatus_fdpic prstatus;	/* NT_PRSTATUS */
 	elf_fpregset_t fpu;		/* NT_PRFPREG */
-	struct task_struct *thread;
-#ifdef ELF_CORE_COPY_XFPREGS
-	elf_fpxregset_t xfpu;		/* ELF_CORE_XFPREG_TYPE */
-#endif
-	struct memelfnote notes[3];
+	struct memelfnote notes[2];
 	int num_notes;
 };
 
@@ -1442,38 +1465,44 @@ struct elf_thread_status
  * we need to keep a linked list of every thread's pr_status and then create
  * a single section for them in the final core file.
  */
-static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
+static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
 {
-	struct task_struct *p = t->thread;
-	int sz = 0;
+	const struct user_regset_view *view = task_user_regset_view(p);
+	struct elf_thread_status *t;
+	int i, ret;
 
-	t->num_notes = 0;
+	t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
+	if (!t)
+		return t;
 
 	fill_prstatus(&t->prstatus, p, signr);
-	elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
+	regset_get(p, &view->regsets[0],
+		   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
 
 	fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
 		  &t->prstatus);
 	t->num_notes++;
-	sz += notesize(&t->notes[0]);
+	*sz += notesize(&t->notes[0]);
+
+	for (i = 1; i < view->n; ++i) {
+		const struct user_regset *regset = &view->regsets[i];
+		if (regset->core_note_type != NT_PRFPREG)
+			continue;
+		if (regset->active && regset->active(p, regset) <= 0)
+			continue;
+		ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
+		if (ret >= 0)
+			t->prstatus.pr_fpvalid = 1;
+		break;
+	}
 
-	t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
 	if (t->prstatus.pr_fpvalid) {
 		fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
 			  &t->fpu);
 		t->num_notes++;
-		sz += notesize(&t->notes[1]);
+		*sz += notesize(&t->notes[1]);
 	}
-
-#ifdef ELF_CORE_COPY_XFPREGS
-	if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
-		fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
-			  sizeof(t->xfpu), &t->xfpu);
-		t->num_notes++;
-		sz += notesize(&t->notes[2]);
-	}
-#endif
-	return sz;
+	return t;
 }
 
 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
@@ -1552,23 +1581,15 @@ static size_t elf_core_vma_data_size(unsigned long mm_flags)
  */
 static int elf_fdpic_core_dump(struct coredump_params *cprm)
 {
-#define	NUM_NOTES	6
 	int has_dumped = 0;
 	int segs;
 	int i;
 	struct vm_area_struct *vma;
 	struct elfhdr *elf = NULL;
 	loff_t offset = 0, dataoff;
-	int numnote;
-	struct memelfnote *notes = NULL;
-	struct elf_prstatus *prstatus = NULL;	/* NT_PRSTATUS */
+	struct memelfnote psinfo_note, auxv_note;
 	struct elf_prpsinfo *psinfo = NULL;	/* NT_PRPSINFO */
- 	LIST_HEAD(thread_list);
- 	struct list_head *t;
-	elf_fpregset_t *fpu = NULL;
-#ifdef ELF_CORE_COPY_XFPREGS
-	elf_fpxregset_t *xfpu = NULL;
-#endif
+	struct elf_thread_status *thread_list = NULL;
 	int thread_status_size = 0;
 	elf_addr_t *auxv;
 	struct elf_phdr *phdr4note = NULL;
@@ -1594,47 +1615,28 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 	elf = kmalloc(sizeof(*elf), GFP_KERNEL);
 	if (!elf)
 		goto end_coredump;
-	prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
-	if (!prstatus)
-		goto end_coredump;
 	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
 	if (!psinfo)
 		goto end_coredump;
-	notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote),
-			      GFP_KERNEL);
-	if (!notes)
-		goto end_coredump;
-	fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
-	if (!fpu)
-		goto end_coredump;
-#ifdef ELF_CORE_COPY_XFPREGS
-	xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
-	if (!xfpu)
-		goto end_coredump;
-#endif
 
 	for (ct = current->mm->core_state->dumper.next;
 					ct; ct = ct->next) {
-		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
+		tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
+					     ct->task, &thread_status_size);
 		if (!tmp)
 			goto end_coredump;
 
-		tmp->thread = ct->task;
-		list_add(&tmp->list, &thread_list);
-	}
-
-	list_for_each(t, &thread_list) {
-		struct elf_thread_status *tmp;
-		int sz;
-
-		tmp = list_entry(t, struct elf_thread_status, list);
-		sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
-		thread_status_size += sz;
+		tmp->next = thread_list;
+		thread_list = tmp;
 	}
 
 	/* now collect the dump for the current */
-	fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
-	elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
+	tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
+				     current, &thread_status_size);
+	if (!tmp)
+		goto end_coredump;
+	tmp->next = thread_list;
+	thread_list = tmp;
 
 	segs = current->mm->map_count;
 	segs += elf_core_extra_phdrs();
@@ -1656,51 +1658,28 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 	 * with info from their /proc.
 	 */
 
-	fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
 	fill_psinfo(psinfo, current->group_leader, current->mm);
-	fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
-
-	numnote = 2;
+	fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
+	thread_status_size += notesize(&psinfo_note);
 
 	auxv = (elf_addr_t *) current->mm->saved_auxv;
-
 	i = 0;
 	do
 		i += 2;
 	while (auxv[i - 2] != AT_NULL);
-	fill_note(&notes[numnote++], "CORE", NT_AUXV,
-		  i * sizeof(elf_addr_t), auxv);
-
-  	/* Try to dump the FPU. */
-	if ((prstatus->pr_fpvalid =
-	     elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
-		fill_note(notes + numnote++,
-			  "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
-#ifdef ELF_CORE_COPY_XFPREGS
-	if (elf_core_copy_task_xfpregs(current, xfpu))
-		fill_note(notes + numnote++,
-			  "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
-#endif
+	fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
+	thread_status_size += notesize(&auxv_note);
 
-	offset += sizeof(*elf);				/* Elf header */
+	offset = sizeof(*elf);				/* Elf header */
 	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
 
 	/* Write notes phdr entry */
-	{
-		int sz = 0;
-
-		for (i = 0; i < numnote; i++)
-			sz += notesize(notes + i);
-
-		sz += thread_status_size;
+	phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
+	if (!phdr4note)
+		goto end_coredump;
 
-		phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
-		if (!phdr4note)
-			goto end_coredump;
-
-		fill_elf_note_phdr(phdr4note, sz, offset);
-		offset += sz;
-	}
+	fill_elf_note_phdr(phdr4note, thread_status_size, offset);
+	offset += thread_status_size;
 
 	/* Page-align dumped data */
 	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
@@ -1753,15 +1732,18 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 		goto end_coredump;
 
  	/* write out the notes section */
-	for (i = 0; i < numnote; i++)
-		if (!writenote(notes + i, cprm))
+	if (!writenote(thread_list->notes, cprm))
+		goto end_coredump;
+	if (!writenote(&psinfo_note, cprm))
+		goto end_coredump;
+	if (!writenote(&auxv_note, cprm))
+		goto end_coredump;
+	for (i = 1; i < thread_list->num_notes; i++)
+		if (!writenote(thread_list->notes + i, cprm))
 			goto end_coredump;
 
 	/* write out the thread status notes section */
-	list_for_each(t, &thread_list) {
-		struct elf_thread_status *tmp =
-				list_entry(t, struct elf_thread_status, list);
-
+	for (tmp = thread_list->next; tmp; tmp = tmp->next) {
 		for (i = 0; i < tmp->num_notes; i++)
 			if (!writenote(&tmp->notes[i], cprm))
 				goto end_coredump;
@@ -1789,23 +1771,16 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
 	}
 
 end_coredump:
-	while (!list_empty(&thread_list)) {
-		struct list_head *tmp = thread_list.next;
-		list_del(tmp);
-		kfree(list_entry(tmp, struct elf_thread_status, list));
+	while (thread_list) {
+		tmp = thread_list;
+		thread_list = thread_list->next;
+		kfree(tmp);
 	}
 	kfree(phdr4note);
 	kfree(elf);
-	kfree(prstatus);
 	kfree(psinfo);
-	kfree(notes);
-	kfree(fpu);
 	kfree(shdr4extnum);
-#ifdef ELF_CORE_COPY_XFPREGS
-	kfree(xfpu);
-#endif
 	return has_dumped;
-#undef NUM_NOTES
 }
 
 #endif		/* CONFIG_ELF_CORE */