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authorAl Viro <viro@zeniv.linux.org.uk>2013-10-05 15:32:35 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2013-11-09 00:16:22 -0500
commitecc8c7725e6c21528329b34acae2a1d64b3af89b (patch)
treeae1790c2ce0fe1c1f02e2bd0795b6636d65b4587
parent7d2f551f6dc933f87933e906e48583169bbc7c27 (diff)
downloadop-kernel-dev-ecc8c7725e6c21528329b34acae2a1d64b3af89b.zip
op-kernel-dev-ecc8c7725e6c21528329b34acae2a1d64b3af89b.tar.gz
new helper: dump_emit()
dump_write() analog, takes core_dump_params instead of file, keeps track of the amount written in cprm->written and checks for cprm->limit. Start using it in binfmt_elf.c... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/binfmt_elf.c60
-rw-r--r--fs/coredump.c14
-rw-r--r--include/linux/binfmts.h1
-rw-r--r--include/linux/coredump.h2
4 files changed, 40 insertions, 37 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 501c8a4..00fd9c9 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1225,35 +1225,23 @@ static int notesize(struct memelfnote *en)
return sz;
}
-#define DUMP_WRITE(addr, nr, foffset) \
- do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
-
-static int alignfile(struct file *file, loff_t *foffset)
+static int alignfile(struct coredump_params *cprm)
{
static const char buf[4] = { 0, };
- DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
- return 1;
+ return dump_emit(cprm, buf, roundup(cprm->written, 4) - cprm->written);
}
-static int writenote(struct memelfnote *men, struct file *file,
- loff_t *foffset)
+static int writenote(struct memelfnote *men, struct coredump_params *cprm)
{
struct elf_note en;
en.n_namesz = strlen(men->name) + 1;
en.n_descsz = men->datasz;
en.n_type = men->type;
- DUMP_WRITE(&en, sizeof(en), foffset);
- DUMP_WRITE(men->name, en.n_namesz, foffset);
- if (!alignfile(file, foffset))
- return 0;
- DUMP_WRITE(men->data, men->datasz, foffset);
- if (!alignfile(file, foffset))
- return 0;
-
- return 1;
+ return dump_emit(cprm, &en, sizeof(en)) &&
+ dump_emit(cprm, men->name, en.n_namesz) && alignfile(cprm) &&
+ dump_emit(cprm, men->data, men->datasz) && alignfile(cprm);
}
-#undef DUMP_WRITE
static void fill_elf_header(struct elfhdr *elf, int segs,
u16 machine, u32 flags)
@@ -1702,7 +1690,7 @@ static size_t get_note_info_size(struct elf_note_info *info)
* 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)
+ struct coredump_params *cprm)
{
bool first = 1;
struct elf_thread_core_info *t = info->thread;
@@ -1710,22 +1698,22 @@ static int write_note_info(struct elf_note_info *info,
do {
int i;
- if (!writenote(&t->notes[0], file, foffset))
+ if (!writenote(&t->notes[0], cprm))
return 0;
- if (first && !writenote(&info->psinfo, file, foffset))
+ if (first && !writenote(&info->psinfo, cprm))
return 0;
- if (first && !writenote(&info->signote, file, foffset))
+ if (first && !writenote(&info->signote, cprm))
return 0;
- if (first && !writenote(&info->auxv, file, foffset))
+ if (first && !writenote(&info->auxv, cprm))
return 0;
if (first && info->files.data &&
- !writenote(&info->files, file, foffset))
+ !writenote(&info->files, cprm))
return 0;
for (i = 1; i < info->thread_notes; ++i)
if (t->notes[i].data &&
- !writenote(&t->notes[i], file, foffset))
+ !writenote(&t->notes[i], cprm))
return 0;
first = 0;
@@ -1935,13 +1923,13 @@ static size_t get_note_info_size(struct elf_note_info *info)
}
static int write_note_info(struct elf_note_info *info,
- struct file *file, loff_t *foffset)
+ struct coredump_params *cprm)
{
int i;
struct list_head *t;
for (i = 0; i < info->numnote; i++)
- if (!writenote(info->notes + i, file, foffset))
+ if (!writenote(info->notes + i, cprm))
return 0;
/* write out the thread status notes section */
@@ -1950,7 +1938,7 @@ static int write_note_info(struct elf_note_info *info,
list_entry(t, struct elf_thread_status, list);
for (i = 0; i < tmp->num_notes; i++)
- if (!writenote(&tmp->notes[i], file, foffset))
+ if (!writenote(&tmp->notes[i], cprm))
return 0;
}
@@ -2136,13 +2124,10 @@ static int elf_core_dump(struct coredump_params *cprm)
offset = dataoff;
- size += sizeof(*elf);
- if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
+ if (!dump_emit(cprm, elf, sizeof(*elf)))
goto end_coredump;
- size += sizeof(*phdr4note);
- if (size > cprm->limit
- || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
+ if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
goto end_coredump;
/* Write program headers for segments dump */
@@ -2164,19 +2149,20 @@ static int elf_core_dump(struct coredump_params *cprm)
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;
- size += sizeof(phdr);
- if (size > cprm->limit
- || !dump_write(cprm->file, &phdr, sizeof(phdr)))
+ if (!dump_emit(cprm, &phdr, sizeof(phdr)))
goto end_coredump;
}
+ size = cprm->written;
if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
goto end_coredump;
+ cprm->written = foffset; /* will disappear */
/* write out the notes section */
- if (!write_note_info(&info, cprm->file, &foffset))
+ if (!write_note_info(&info, cprm))
goto end_coredump;
+ foffset = cprm->written;
if (elf_coredump_extra_notes_write(cprm->file, &foffset))
goto end_coredump;
diff --git a/fs/coredump.c b/fs/coredump.c
index 42c3b84..319f973 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -693,6 +693,20 @@ int dump_write(struct file *file, const void *addr, int nr)
}
EXPORT_SYMBOL(dump_write);
+int dump_emit(struct coredump_params *cprm, const void *addr, int nr)
+{
+ struct file *file = cprm->file;
+ if (dump_interrupted() || !access_ok(VERIFY_READ, addr, nr))
+ return 0;
+ if (cprm->written + nr > cprm->limit)
+ return 0;
+ if (file->f_op->write(file, addr, nr, &file->f_pos) != nr)
+ return 0;
+ cprm->written += nr;
+ return 1;
+}
+EXPORT_SYMBOL(dump_emit);
+
int dump_seek(struct file *file, loff_t off)
{
int ret = 1;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index e8112ae..8aa507e 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -61,6 +61,7 @@ struct coredump_params {
struct file *file;
unsigned long limit;
unsigned long mm_flags;
+ loff_t written;
};
/*
diff --git a/include/linux/coredump.h b/include/linux/coredump.h
index a98f1ca..2959376 100644
--- a/include/linux/coredump.h
+++ b/include/linux/coredump.h
@@ -10,8 +10,10 @@
* These are the only things you should do on a core-file: use only these
* functions to write out all the necessary info.
*/
+struct coredump_params;
extern int dump_write(struct file *file, const void *addr, int nr);
extern int dump_seek(struct file *file, loff_t off);
+extern int dump_emit(struct coredump_params *cprm, const void *addr, int nr);
#ifdef CONFIG_COREDUMP
extern void do_coredump(siginfo_t *siginfo);
#else
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