mm: introduce coredump parameter structure

Introduce coredump parameter data structure (struct coredump_params) to
simplify binfmt->core_dump() arguments.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_aout.c

@@ -32,7 +32,7 @@
 
 static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
 static int load_aout_library(struct file*);
-static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
+static int aout_core_dump(struct coredump_params *cprm);
 
 static struct linux_binfmt aout_format = {
 	.module		= THIS_MODULE,
@@ -89,8 +89,9 @@ if (file->f_op->llseek) { \
  * dumping of the process results in another error..
  */
 
-static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
+static int aout_core_dump(struct coredump_params *cprm)
 {
+	struct file *file = cprm->file;
 	mm_segment_t fs;
 	int has_dumped = 0;
 	unsigned long dump_start, dump_size;
@@ -108,16 +109,16 @@ static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file, u
 	current->flags |= PF_DUMPCORE;
        	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
 	dump.u_ar0 = offsetof(struct user, regs);
-	dump.signal = signr;
-	aout_dump_thread(regs, &dump);
+	dump.signal = cprm->signr;
+	aout_dump_thread(cprm->regs, &dump);
 
 /* If the size of the dump file exceeds the rlimit, then see what would happen
    if we wrote the stack, but not the data area.  */
-	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > limit)
+	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
 		dump.u_dsize = 0;
 
 /* Make sure we have enough room to write the stack and data areas. */
-	if ((dump.u_ssize + 1) * PAGE_SIZE > limit)
+	if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
 		dump.u_ssize = 0;
 
 /* make sure we actually have a data and stack area to dump */

fs/binfmt_elf.c

@@ -45,7 +45,7 @@ static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
  * don't even try.
  */
 #ifdef CONFIG_ELF_CORE
-static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
+static int elf_core_dump(struct coredump_params *cprm);
 #else
 #define elf_core_dump	NULL
 #endif
@@ -1272,8 +1272,9 @@ static int writenote(struct memelfnote *men, struct file *file,
 }
 #undef DUMP_WRITE
 
-#define DUMP_WRITE(addr, nr)	\
-	if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
+#define DUMP_WRITE(addr, nr)				\
+	if ((size += (nr)) > cprm->limit ||		\
+	    !dump_write(cprm->file, (addr), (nr)))	\
 		goto end_coredump;
 
 static void fill_elf_header(struct elfhdr *elf, int segs,
@@ -1901,7 +1902,7 @@ static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
  * and then they are actually written out.  If we run out of core limit
  * we just truncate.
  */
-static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
+static int elf_core_dump(struct coredump_params *cprm)
 {
 	int has_dumped = 0;
 	mm_segment_t fs;
@@ -1947,7 +1948,7 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
 	 * notes.  This also sets up the file header.
 	 */
 	if (!fill_note_info(elf, segs + 1, /* including notes section */
-			    &info, signr, regs))
+			    &info, cprm->signr, cprm->regs))
 		goto cleanup;
 
 	has_dumped = 1;
@@ -2009,14 +2010,14 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
 #endif
 
  	/* write out the notes section */
-	if (!write_note_info(&info, file, &foffset))
+	if (!write_note_info(&info, cprm->file, &foffset))
 		goto end_coredump;
 
-	if (elf_coredump_extra_notes_write(file, &foffset))
+	if (elf_coredump_extra_notes_write(cprm->file, &foffset))
 		goto end_coredump;
 
 	/* Align to page */
-	if (!dump_seek(file, dataoff - foffset))
+	if (!dump_seek(cprm->file, dataoff - foffset))
 		goto end_coredump;
 
 	for (vma = first_vma(current, gate_vma); vma != NULL;
@@ -2033,12 +2034,13 @@ static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, un
 			page = get_dump_page(addr);
 			if (page) {
 				void *kaddr = kmap(page);
-				stop = ((size += PAGE_SIZE) > limit) ||
-					!dump_write(file, kaddr, PAGE_SIZE);
+				stop = ((size += PAGE_SIZE) > cprm->limit) ||
+					!dump_write(cprm->file, kaddr,
+						    PAGE_SIZE);
 				kunmap(page);
 				page_cache_release(page);
 			} else
-				stop = !dump_seek(file, PAGE_SIZE);
+				stop = !dump_seek(cprm->file, PAGE_SIZE);
 			if (stop)
 				goto end_coredump;
 		}

fs/binfmt_elf_fdpic.c

@@ -76,7 +76,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
 					     struct file *, struct mm_struct *);
 
 #ifdef CONFIG_ELF_CORE
-static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
+static int elf_fdpic_core_dump(struct coredump_params *cprm);
 #endif
 
 static struct linux_binfmt elf_fdpic_format = {
@@ -1326,8 +1326,9 @@ static int writenote(struct memelfnote *men, struct file *file)
 #undef DUMP_WRITE
 #undef DUMP_SEEK
 
-#define DUMP_WRITE(addr, nr)	\
-	if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
+#define DUMP_WRITE(addr, nr)				\
+	if ((size += (nr)) > cprm->limit ||		\
+	    !dump_write(cprm->file, (addr), (nr)))	\
 		goto end_coredump;
 
 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
@@ -1582,8 +1583,7 @@ static int elf_fdpic_dump_segments(struct file *file, size_t *size,
  * and then they are actually written out.  If we run out of core limit
  * we just truncate.
  */
-static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
-			       struct file *file, unsigned long limit)
+static int elf_fdpic_core_dump(struct coredump_params *cprm)
 {
 #define	NUM_NOTES	6
 	int has_dumped = 0;
@@ -1642,7 +1642,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
 		goto cleanup;
 #endif
 
-	if (signr) {
+	if (cprm->signr) {
 		struct core_thread *ct;
 		struct elf_thread_status *tmp;
 
@@ -1661,14 +1661,14 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
 			int sz;
 
 			tmp = list_entry(t, struct elf_thread_status, list);
-			sz = elf_dump_thread_status(signr, tmp);
+			sz = elf_dump_thread_status(cprm->signr, tmp);
 			thread_status_size += sz;
 		}
 	}
 
 	/* now collect the dump for the current */
-	fill_prstatus(prstatus, current, signr);
-	elf_core_copy_regs(&prstatus->pr_reg, regs);
+	fill_prstatus(prstatus, current, cprm->signr);
+	elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
 
 	segs = current->mm->map_count;
 #ifdef ELF_CORE_EXTRA_PHDRS
@@ -1703,7 +1703,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
 
   	/* Try to dump the FPU. */
 	if ((prstatus->pr_fpvalid =
-	     elf_core_copy_task_fpregs(current, regs, fpu)))
+	     elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
 		fill_note(notes + numnote++,
 			  "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
 #ifdef ELF_CORE_COPY_XFPREGS
@@ -1774,7 +1774,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
 
  	/* write out the notes section */
 	for (i = 0; i < numnote; i++)
-		if (!writenote(notes + i, file))
+		if (!writenote(notes + i, cprm->file))
 			goto end_coredump;
 
 	/* write out the thread status notes section */
@@ -1783,14 +1783,15 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
 				list_entry(t, struct elf_thread_status, list);
 
 		for (i = 0; i < tmp->num_notes; i++)
-			if (!writenote(&tmp->notes[i], file))
+			if (!writenote(&tmp->notes[i], cprm->file))
 				goto end_coredump;
 	}
 
-	if (!dump_seek(file, dataoff))
+	if (!dump_seek(cprm->file, dataoff))
 		goto end_coredump;
 
-	if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
+	if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
+				    mm_flags) < 0)
 		goto end_coredump;
 
 #ifdef ELF_CORE_WRITE_EXTRA_DATA

fs/binfmt_flat.c

@@ -87,7 +87,7 @@ static int load_flat_shared_library(int id, struct lib_info *p);
 #endif
 
 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
-static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
+static int flat_core_dump(struct coredump_params *cprm);
 
 static struct linux_binfmt flat_format = {
 	.module		= THIS_MODULE,
@@ -102,10 +102,10 @@ static struct linux_binfmt flat_format = {
  * Currently only a stub-function.
  */
 
-static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
+static int flat_core_dump(struct coredump_params *cprm)
 {
 	printk("Process %s:%d received signr %d and should have core dumped\n",
-			current->comm, current->pid, (int) signr);
+			current->comm, current->pid, (int) cprm->signr);
 	return(1);
 }
 

fs/binfmt_som.c

@@ -43,7 +43,7 @@ static int load_som_library(struct file *);
  * don't even try.
  */
 #if 0
-static int som_core_dump(long signr, struct pt_regs *regs, unsigned long limit);
+static int som_core_dump(struct coredump_params *cprm);
 #else
 #define som_core_dump	NULL
 #endif

fs/exec.c

@@ -1763,17 +1763,20 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
 	struct mm_struct *mm = current->mm;
 	struct linux_binfmt * binfmt;
 	struct inode * inode;
-	struct file * file;
 	const struct cred *old_cred;
 	struct cred *cred;
 	int retval = 0;
 	int flag = 0;
 	int ispipe = 0;
-	unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
 	char **helper_argv = NULL;
 	int helper_argc = 0;
 	int dump_count = 0;
 	static atomic_t core_dump_count = ATOMIC_INIT(0);
+	struct coredump_params cprm = {
+		.signr = signr,
+		.regs = regs,
+		.limit = current->signal->rlim[RLIMIT_CORE].rlim_cur,
+	};
 
 	audit_core_dumps(signr);
 
@@ -1829,15 +1832,15 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
 	ispipe = format_corename(corename, signr);
 	unlock_kernel();
 
-	if ((!ispipe) && (core_limit < binfmt->min_coredump))
+	if ((!ispipe) && (cprm.limit < binfmt->min_coredump))
 		goto fail_unlock;
 
  	if (ispipe) {
-		if (core_limit == 0) {
+		if (cprm.limit == 0) {
 			/*
 			 * Normally core limits are irrelevant to pipes, since
 			 * we're not writing to the file system, but we use
-			 * core_limit of 0 here as a speacial value. Any
+			 * cprm.limit of 0 here as a speacial value. Any
 			 * non-zero limit gets set to RLIM_INFINITY below, but
 			 * a limit of 0 skips the dump.  This is a consistent
 			 * way to catch recursive crashes.  We can still crash
@@ -1870,25 +1873,25 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
 			goto fail_dropcount;
 		}
 
-		core_limit = RLIM_INFINITY;
+		cprm.limit = RLIM_INFINITY;
 
 		/* SIGPIPE can happen, but it's just never processed */
 		if (call_usermodehelper_pipe(helper_argv[0], helper_argv, NULL,
-				&file)) {
+				&cprm.file)) {
  			printk(KERN_INFO "Core dump to %s pipe failed\n",
 			       corename);
 			goto fail_dropcount;
  		}
  	} else
- 		file = filp_open(corename,
+		cprm.file = filp_open(corename,
 				 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
 				 0600);
-	if (IS_ERR(file))
+	if (IS_ERR(cprm.file))
 		goto fail_dropcount;
-	inode = file->f_path.dentry->d_inode;
+	inode = cprm.file->f_path.dentry->d_inode;
 	if (inode->i_nlink > 1)
 		goto close_fail;	/* multiple links - don't dump */
-	if (!ispipe && d_unhashed(file->f_path.dentry))
+	if (!ispipe && d_unhashed(cprm.file->f_path.dentry))
 		goto close_fail;
 
 	/* AK: actually i see no reason to not allow this for named pipes etc.,
@@ -1901,21 +1904,22 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
 	 */
 	if (inode->i_uid != current_fsuid())
 		goto close_fail;
-	if (!file->f_op)
+	if (!cprm.file->f_op)
 		goto close_fail;
-	if (!file->f_op->write)
+	if (!cprm.file->f_op->write)
 		goto close_fail;
-	if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
+	if (!ispipe &&
+	    do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file) != 0)
 		goto close_fail;
 
-	retval = binfmt->core_dump(signr, regs, file, core_limit);
+	retval = binfmt->core_dump(&cprm);
 
 	if (retval)
 		current->signal->group_exit_code |= 0x80;
 close_fail:
 	if (ispipe && core_pipe_limit)
-		wait_for_dump_helpers(file);
-	filp_close(file, NULL);
+		wait_for_dump_helpers(cprm.file);
+	filp_close(cprm.file, NULL);
 fail_dropcount:
 	if (dump_count)
 		atomic_dec(&core_dump_count);

include/linux/binfmts.h

@@ -68,6 +68,14 @@ struct linux_binprm{
 
 #define BINPRM_MAX_RECURSION 4
 
+/* Function parameter for binfmt->coredump */
+struct coredump_params {
+	long signr;
+	struct pt_regs *regs;
+	struct file *file;
+	unsigned long limit;
+};
+
 /*
  * This structure defines the functions that are used to load the binary formats that
  * linux accepts.
@@ -77,7 +85,7 @@ struct linux_binfmt {
 	struct module *module;
 	int (*load_binary)(struct linux_binprm *, struct  pt_regs * regs);
 	int (*load_shlib)(struct file *);
-	int (*core_dump)(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
+	int (*core_dump)(struct coredump_params *cprm);
 	unsigned long min_coredump;	/* minimal dump size */
 	int hasvdso;
 };