The patch titled
binfmt: introduce coredump parameter structure
has been removed from the -mm tree. Its filename was
binfmt-introduce-coredump-parameter-structure.patch
This patch was dropped because an updated version will be merged
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: binfmt: introduce coredump parameter structure
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
These patches are for fixing coredump mm->flags consistency issue.
---
1787 if (mm->core_state || !get_dumpable(mm)) { <- (1)
1788 up_write(&mm->mmap_sem);
1789 put_cred(cred);
1790 goto fail;
1791 }
1792
[...]
1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2)
1799 flag = O_EXCL; /* Stop rewrite attacks */
1800 cred->fsuid = 0; /* Dump root private */
1801 }
---
Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).
To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core. This series also introduce
coredump parameter structure for simplify bimfmt->core_dump interface.
This patch:
Introduce coredump parameter data structure (struct coredump_params) for
simplifying binfmt->core_dump() arguments. This also cleanup DUMP_WRITE()
in elf_core_dump() by style issue.
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Suggested-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@xxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Mike Frysinger <vapier@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Paul Mundt <lethal@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_aout.c | 13 +++++++------
fs/binfmt_elf.c | 38 ++++++++++++++++++++++----------------
fs/binfmt_elf_fdpic.c | 28 ++++++++++++++--------------
fs/binfmt_flat.c | 6 +++---
fs/binfmt_som.c | 2 +-
fs/exec.c | 38 +++++++++++++++++++++-----------------
include/linux/binfmts.h | 10 +++++++++-
7 files changed, 77 insertions(+), 58 deletions(-)
diff -puN fs/binfmt_aout.c~binfmt-introduce-coredump-parameter-structure fs/binfmt_aout.c
--- a/fs/binfmt_aout.c~binfmt-introduce-coredump-parameter-structure
+++ a/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, st
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 */
diff -puN fs/binfmt_elf.c~binfmt-introduce-coredump-parameter-structure fs/binfmt_elf.c
--- a/fs/binfmt_elf.c~binfmt-introduce-coredump-parameter-structure
+++ a/fs/binfmt_elf.c
@@ -45,7 +45,7 @@ static unsigned long elf_map(struct file
* don't even try.
*/
#if defined(USE_ELF_CORE_DUMP) && defined(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
@@ -1277,10 +1277,6 @@ static int writenote(struct memelfnote *
}
#undef DUMP_WRITE
-#define DUMP_WRITE(addr, nr) \
- if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
- goto end_coredump;
-
static void fill_elf_header(struct elfhdr *elf, int segs,
u16 machine, u32 flags, u8 osabi)
{
@@ -1906,7 +1902,7 @@ static struct vm_area_struct *next_vma(s
* 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;
@@ -1952,7 +1948,7 @@ static int elf_core_dump(long signr, str
* 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;
@@ -1961,7 +1957,10 @@ static int elf_core_dump(long signr, str
fs = get_fs();
set_fs(KERNEL_DS);
- DUMP_WRITE(elf, sizeof(*elf));
+ size += sizeof(*elf);
+ if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
+ goto end_coredump;
+
offset += sizeof(*elf); /* Elf header */
offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
foffset = offset;
@@ -1975,7 +1974,10 @@ static int elf_core_dump(long signr, str
fill_elf_note_phdr(&phdr, sz, offset);
offset += sz;
- DUMP_WRITE(&phdr, sizeof(phdr));
+ size += sizeof(phdr);
+ if (size > cprm->limit ||
+ !dump_write(cprm->file, &phdr, sizeof(phdr)))
+ goto end_coredump;
}
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
@@ -2006,7 +2008,10 @@ static int elf_core_dump(long signr, str
phdr.p_flags |= PF_X;
phdr.p_align = ELF_EXEC_PAGESIZE;
- DUMP_WRITE(&phdr, sizeof(phdr));
+ size += sizeof(phdr);
+ if (size > cprm->limit ||
+ !dump_write(cprm->file, &phdr, sizeof(phdr)))
+ goto end_coredump;
}
#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
@@ -2014,14 +2019,14 @@ static int elf_core_dump(long signr, str
#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;
@@ -2038,12 +2043,13 @@ static int elf_core_dump(long signr, str
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;
}
diff -puN fs/binfmt_elf_fdpic.c~binfmt-introduce-coredump-parameter-structure fs/binfmt_elf_fdpic.c
--- a/fs/binfmt_elf_fdpic.c~binfmt-introduce-coredump-parameter-structure
+++ a/fs/binfmt_elf_fdpic.c
@@ -76,7 +76,7 @@ static int elf_fdpic_map_file_by_direct_
struct file *, struct mm_struct *);
#if defined(USE_ELF_CORE_DUMP) && defined(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 = {
@@ -1582,8 +1582,7 @@ static int elf_fdpic_dump_segments(struc
* 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 +1641,7 @@ static int elf_fdpic_core_dump(long sign
goto cleanup;
#endif
- if (signr) {
+ if (cprm->signr) {
struct core_thread *ct;
struct elf_thread_status *tmp;
@@ -1661,14 +1660,14 @@ static int elf_fdpic_core_dump(long sign
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 +1702,7 @@ static int elf_fdpic_core_dump(long sign
/* 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 +1773,7 @@ static int elf_fdpic_core_dump(long sign
/* 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 */
@@ -1783,25 +1782,26 @@ static int elf_fdpic_core_dump(long sign
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
ELF_CORE_WRITE_EXTRA_DATA;
#endif
- if (file->f_pos != offset) {
+ if (cprm->file->f_pos != offset) {
/* Sanity check */
printk(KERN_WARNING
"elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
- file->f_pos, offset);
+ cprm->file->f_pos, offset);
}
end_coredump:
diff -puN fs/binfmt_flat.c~binfmt-introduce-coredump-parameter-structure fs/binfmt_flat.c
--- a/fs/binfmt_flat.c~binfmt-introduce-coredump-parameter-structure
+++ a/fs/binfmt_flat.c
@@ -87,7 +87,7 @@ static int load_flat_shared_library(int
#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);
}
diff -puN fs/binfmt_som.c~binfmt-introduce-coredump-parameter-structure fs/binfmt_som.c
--- a/fs/binfmt_som.c~binfmt-introduce-coredump-parameter-structure
+++ a/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
diff -puN fs/exec.c~binfmt-introduce-coredump-parameter-structure fs/exec.c
--- a/fs/exec.c~binfmt-introduce-coredump-parameter-structure
+++ a/fs/exec.c
@@ -1761,17 +1761,20 @@ void do_coredump(long signr, int exit_co
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);
@@ -1827,15 +1830,15 @@ void do_coredump(long signr, int exit_co
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
@@ -1868,25 +1871,25 @@ void do_coredump(long signr, int exit_co
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.,
@@ -1899,21 +1902,22 @@ void do_coredump(long signr, int exit_co
*/
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);
diff -puN include/linux/binfmts.h~binfmt-introduce-coredump-parameter-structure include/linux/binfmts.h
--- a/include/linux/binfmts.h~binfmt-introduce-coredump-parameter-structure
+++ a/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;
};
_
Patches currently in -mm which might be from mhiramat@xxxxxxxxxx are
linux-next.patch
binfmt-introduce-coredump-parameter-structure.patch
binfmt-pass-mm-flags-as-a-coredump-parameter-for-consistency.patch
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