* [PATCH 01/10] binfmt_flat: assorted cleanups
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 02/10] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
` (8 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Remove excessive casts, do some code grouping, etc.
No functional changes.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 118 ++++++++++++++++++++++++++-----------------------------
1 file changed, 56 insertions(+), 62 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index caf9e39bb8..085059d879 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -80,7 +80,7 @@ struct lib_info {
unsigned long text_len; /* Length of text segment */
unsigned long entry; /* Start address for this module */
unsigned long build_date; /* When this one was compiled */
- short loaded; /* Has this library been loaded? */
+ bool loaded; /* Has this library been loaded? */
} lib_list[MAX_SHARED_LIBS];
};
@@ -107,7 +107,7 @@ static struct linux_binfmt flat_format = {
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) cprm->siginfo->si_signo);
+ current->comm, current->pid, cprm->siginfo->si_signo);
return(1);
}
@@ -190,7 +190,7 @@ static int decompress_exec(
loff_t fpos;
int ret, retval;
- DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
+ DBG_FLT("decompress_exec(offset=%lx,buf=%p,len=%lx)\n",offset, dst, len);
memset(&strm, 0, sizeof(strm));
strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
@@ -358,8 +358,8 @@ calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
text_len = p->lib_list[id].text_len;
if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
- printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
- (int) r,(int)(start_brk-start_data+text_len),(int)text_len);
+ printk("BINFMT_FLAT: reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
+ r, start_brk-start_data+text_len, text_len);
goto failed;
}
@@ -383,7 +383,7 @@ failed:
static void old_reloc(unsigned long rl)
{
#ifdef DEBUG
- char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
+ static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
#endif
flat_v2_reloc_t r;
unsigned long *ptr;
@@ -397,8 +397,8 @@ static void old_reloc(unsigned long rl)
#ifdef DEBUG
printk("Relocation of variable at DATASEG+%x "
- "(address %p, currently %x) into segment %s\n",
- r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
+ "(address %p, currently %lx) into segment %s\n",
+ r.reloc.offset, ptr, *ptr, segment[r.reloc.type]);
#endif
switch (r.reloc.type) {
@@ -417,7 +417,7 @@ static void old_reloc(unsigned long rl)
}
#ifdef DEBUG
- printk("Relocation became %x\n", (int)*ptr);
+ printk("Relocation became %lx\n", *ptr);
#endif
}
@@ -427,17 +427,15 @@ static int load_flat_file(struct linux_binprm * bprm,
struct lib_info *libinfo, int id, unsigned long *extra_stack)
{
struct flat_hdr * hdr;
- unsigned long textpos = 0, datapos = 0, result;
- unsigned long realdatastart = 0;
- unsigned long text_len, data_len, bss_len, stack_len, flags;
- unsigned long full_data;
- unsigned long len, memp = 0;
- unsigned long memp_size, extra, rlim;
- unsigned long *reloc = 0, *rp;
+ unsigned long textpos, datapos, realdatastart;
+ unsigned long text_len, data_len, bss_len, stack_len, full_data, flags;
+ unsigned long len, memp, memp_size, extra, rlim;
+ unsigned long *reloc, *rp;
struct inode *inode;
- int i, rev, relocs = 0;
+ int i, rev, relocs;
loff_t fpos;
unsigned long start_code, end_code;
+ ssize_t result;
int ret;
hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
@@ -481,8 +479,8 @@ static int load_flat_file(struct linux_binprm * bprm,
/* Don't allow old format executables to use shared libraries */
if (rev == OLD_FLAT_VERSION && id != 0) {
- printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
- (int) FLAT_VERSION);
+ printk("BINFMT_FLAT: shared libraries are not available before rev 0x%lx\n",
+ FLAT_VERSION);
ret = -ENOEXEC;
goto err;
}
@@ -517,11 +515,9 @@ static int load_flat_file(struct linux_binprm * bprm,
/* Flush all traces of the currently running executable */
if (id == 0) {
- result = flush_old_exec(bprm);
- if (result) {
- ret = result;
+ ret = flush_old_exec(bprm);
+ if (ret)
goto err;
- }
/* OK, This is the point of no return */
set_personality(PER_LINUX_32BIT);
@@ -549,33 +545,33 @@ static int load_flat_file(struct linux_binprm * bprm,
textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
MAP_PRIVATE|MAP_EXECUTABLE, 0);
if (!textpos || IS_ERR_VALUE(textpos)) {
- if (!textpos)
- textpos = (unsigned long) -ENOMEM;
- printk("Unable to mmap process text, errno %d\n", (int)-textpos);
ret = textpos;
+ if (!textpos)
+ ret = -ENOMEM;
+ printk("Unable to mmap process text, errno %d\n", ret);
goto err;
}
len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
len = PAGE_ALIGN(len);
- realdatastart = vm_mmap(0, 0, len,
+ realdatastart = vm_mmap(NULL, 0, len,
PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
+ ret = realdatastart;
if (!realdatastart)
- realdatastart = (unsigned long) -ENOMEM;
- printk("Unable to allocate RAM for process data, errno %d\n",
- (int)-realdatastart);
+ ret = -ENOMEM;
+ printk("Unable to allocate RAM for process data, "
+ "errno %d\n", ret);
vm_munmap(textpos, text_len);
- ret = realdatastart;
goto err;
}
datapos = ALIGN(realdatastart +
MAX_SHARED_LIBS * sizeof(unsigned long),
FLAT_DATA_ALIGN);
- DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
- (int)(data_len + bss_len + stack_len), (int)datapos);
+ DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%ld bytes): %lx\n",
+ data_len + bss_len + stack_len, datapos);
fpos = ntohl(hdr->data_start);
#ifdef CONFIG_BINFMT_ZFLAT
@@ -589,29 +585,30 @@ static int load_flat_file(struct linux_binprm * bprm,
full_data);
}
if (IS_ERR_VALUE(result)) {
- printk("Unable to read data+bss, errno %d\n", (int)-result);
+ ret = result;
+ printk("Unable to read data+bss, errno %d\n", ret);
vm_munmap(textpos, text_len);
vm_munmap(realdatastart, len);
- ret = result;
goto err;
}
- reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
+ reloc = (unsigned long *)
+ (datapos + (ntohl(hdr->reloc_start) - text_len));
memp = realdatastart;
memp_size = len;
} else {
len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
len = PAGE_ALIGN(len);
- textpos = vm_mmap(0, 0, len,
+ textpos = vm_mmap(NULL, 0, len,
PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
if (!textpos || IS_ERR_VALUE(textpos)) {
- if (!textpos)
- textpos = (unsigned long) -ENOMEM;
- printk("Unable to allocate RAM for process text/data, errno %d\n",
- (int)-textpos);
ret = textpos;
+ if (!textpos)
+ ret = -ENOMEM;
+ printk("Unable to allocate RAM for process text/data, "
+ "errno %d\n", ret);
goto err;
}
@@ -652,21 +649,19 @@ static int load_flat_file(struct linux_binprm * bprm,
full_data);
}
if (IS_ERR_VALUE(result)) {
- printk("Unable to read code+data+bss, errno %d\n",(int)-result);
+ ret = result;
+ printk("Unable to read code+data+bss, errno %d\n", ret);
vm_munmap(textpos, text_len + data_len + extra +
MAX_SHARED_LIBS * sizeof(unsigned long));
- ret = result;
goto err;
}
}
- if (flags & FLAT_FLAG_KTRACE)
- printk("Mapping is %x, Entry point is %x, data_start is %x\n",
- (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
-
- /* The main program needs a little extra setup in the task structure */
start_code = textpos + sizeof (struct flat_hdr);
end_code = textpos + text_len;
+ text_len -= sizeof(struct flat_hdr); /* the real code len */
+
+ /* The main program needs a little extra setup in the task structure */
if (id == 0) {
current->mm->start_code = start_code;
current->mm->end_code = end_code;
@@ -684,16 +679,14 @@ static int load_flat_file(struct linux_binprm * bprm,
current->mm->context.end_brk = memp + memp_size - stack_len;
}
- if (flags & FLAT_FLAG_KTRACE)
- printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
- id ? "Lib" : "Load", bprm->filename,
- (int) start_code, (int) end_code,
- (int) datapos,
- (int) (datapos + data_len),
- (int) (datapos + data_len),
- (int) (((datapos + data_len + bss_len) + 3) & ~3));
-
- text_len -= sizeof(struct flat_hdr); /* the real code len */
+ if (flags & FLAT_FLAG_KTRACE) {
+ printk("Mapping is %lx, Entry point is %x, data_start is %x\n",
+ textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
+ printk("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
+ id ? "Lib" : "Load", bprm->filename,
+ start_code, end_code, datapos, datapos + data_len,
+ datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
+ }
/* Store the current module values into the global library structure */
libinfo->lib_list[id].start_code = start_code;
@@ -869,6 +862,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
int i, j;
memset(&libinfo, 0, sizeof(libinfo));
+
/*
* We have to add the size of our arguments to our stack size
* otherwise it's too easy for users to create stack overflows
@@ -899,7 +893,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
- DBG_FLT("p=%x\n", (int)p);
+ DBG_FLT("p=%lx\n", p);
/* copy the arg pages onto the stack, this could be more efficient :-) */
for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
@@ -930,9 +924,9 @@ static int load_flat_binary(struct linux_binprm * bprm)
#ifdef FLAT_PLAT_INIT
FLAT_PLAT_INIT(regs);
#endif
- DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
- (int)regs, (int)start_addr, (int)current->mm->start_stack);
-
+
+ DBG_FLT("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
+ regs, start_addr, current->mm->start_stack);
start_thread(regs, start_addr, current->mm->start_stack);
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 02/10] elf_fdpic_transfer_args_to_stack(): make it generic
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-12 21:27 ` [PATCH 01/10] binfmt_flat: assorted cleanups Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 03/10] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
` (7 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
This copying of arguments and environment is common to both NOMMU
binary formats we support. Let's make the elf_fdpic version available
to the flat format as well.
While at it, improve the code a bit not to copy below the actual
data area.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_elf_fdpic.c | 38 ++------------------------------------
fs/exec.c | 33 +++++++++++++++++++++++++++++++++
include/linux/binfmts.h | 2 ++
3 files changed, 37 insertions(+), 36 deletions(-)
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 203589311b..464a972e88 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -67,8 +67,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
struct elf_fdpic_params *);
#ifndef CONFIG_MMU
-static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
- unsigned long *);
static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
struct file *,
struct mm_struct *);
@@ -515,8 +513,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
sp = mm->start_stack;
/* stack the program arguments and environment */
- if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
+ if (transfer_args_to_stack(bprm, &sp) < 0)
return -EFAULT;
+ sp &= ~15;
#endif
/*
@@ -711,39 +710,6 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
/*****************************************************************************/
/*
- * transfer the program arguments and environment from the holding pages onto
- * the stack
- */
-#ifndef CONFIG_MMU
-static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
- unsigned long *_sp)
-{
- unsigned long index, stop, sp;
- char *src;
- int ret = 0;
-
- stop = bprm->p >> PAGE_SHIFT;
- sp = *_sp;
-
- for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
- src = kmap(bprm->page[index]);
- sp -= PAGE_SIZE;
- if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
- ret = -EFAULT;
- kunmap(bprm->page[index]);
- if (ret < 0)
- goto out;
- }
-
- *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
-
-out:
- return ret;
-}
-#endif
-
-/*****************************************************************************/
-/*
* load the appropriate binary image (executable or interpreter) into memory
* - we assume no MMU is available
* - if no other PIC bits are set in params->hdr->e_flags
diff --git a/fs/exec.c b/fs/exec.c
index 887c1c955d..ef0df2f092 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -762,6 +762,39 @@ out_unlock:
}
EXPORT_SYMBOL(setup_arg_pages);
+#else
+
+/*
+ * Transfer the program arguments and environment from the holding pages
+ * onto the stack. The provided stack pointer is adjusted accordingly.
+ */
+int transfer_args_to_stack(struct linux_binprm *bprm,
+ unsigned long *sp_location)
+{
+ unsigned long index, stop, sp;
+ int ret = 0;
+
+ stop = bprm->p >> PAGE_SHIFT;
+ sp = *sp_location;
+
+ for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
+ unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;
+ char *src = kmap(bprm->page[index]) + offset;
+ sp -= PAGE_SIZE - offset;
+ if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0)
+ ret = -EFAULT;
+ kunmap(bprm->page[index]);
+ if (ret)
+ goto out;
+ }
+
+ *sp_location = sp;
+
+out:
+ return ret;
+}
+EXPORT_SYMBOL(transfer_args_to_stack);
+
#endif /* CONFIG_MMU */
static struct file *do_open_execat(int fd, struct filename *name, int flags)
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 314b3caa70..1303b570b1 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -113,6 +113,8 @@ extern int suid_dumpable;
extern int setup_arg_pages(struct linux_binprm * bprm,
unsigned long stack_top,
int executable_stack);
+extern int transfer_args_to_stack(struct linux_binprm *bprm,
+ unsigned long *sp_location);
extern int bprm_change_interp(char *interp, struct linux_binprm *bprm);
extern int copy_strings_kernel(int argc, const char *const *argv,
struct linux_binprm *bprm);
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 03/10] binfmt_flat: use generic transfer_args_to_stack()
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-12 21:27 ` [PATCH 01/10] binfmt_flat: assorted cleanups Nicolas Pitre
2016-07-12 21:27 ` [PATCH 02/10] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 04/10] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
` (6 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
This gets rid of the rather ugly, open coded and suboptimal copy code.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 085059d879..64feb873f0 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -854,10 +854,8 @@ static int load_flat_binary(struct linux_binprm * bprm)
{
struct lib_info libinfo;
struct pt_regs *regs = current_pt_regs();
- unsigned long p = bprm->p;
- unsigned long stack_len;
+ unsigned long sp, stack_len;
unsigned long start_addr;
- unsigned long *sp;
int res;
int i, j;
@@ -892,15 +890,15 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
- p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
- DBG_FLT("p=%lx\n", p);
+ sp = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
+ DBG_FLT("sp=%lx\n", sp);
- /* copy the arg pages onto the stack, this could be more efficient :-) */
- for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
- * (char *) --p =
- ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
+ /* copy the arg pages onto the stack */
+ res = transfer_args_to_stack(bprm, &sp);
+ if (res)
+ return res;
- sp = (unsigned long *) create_flat_tables(p, bprm);
+ sp = create_flat_tables(sp, bprm);
/* Fake some return addresses to ensure the call chain will
* initialise library in order for us. We are required to call
@@ -912,14 +910,14 @@ static int load_flat_binary(struct linux_binprm * bprm)
for (i = MAX_SHARED_LIBS-1; i>0; i--) {
if (libinfo.lib_list[i].loaded) {
/* Push previos first to call address */
- --sp; put_user(start_addr, sp);
+ --sp; put_user(start_addr, (unsigned long *)sp);
start_addr = libinfo.lib_list[i].entry;
}
}
#endif
/* Stash our initial stack pointer into the mm structure */
- current->mm->start_stack = (unsigned long )sp;
+ current->mm->start_stack = sp;
#ifdef FLAT_PLAT_INIT
FLAT_PLAT_INIT(regs);
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 04/10] binfmt_flat: clean up create_flat_tables() and stack accesses
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (2 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 03/10] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 05/10] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
` (5 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
In addition to better code clarity, this brings proper usage of
user memory accessors everywhere the stack is touched. This is essential
for making this work on MMU systems.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 117 ++++++++++++++++++++++++++++++-------------------------
1 file changed, 63 insertions(+), 54 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 64feb873f0..9538901fe8 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -115,50 +115,58 @@ static int flat_core_dump(struct coredump_params *cprm)
/*
* create_flat_tables() parses the env- and arg-strings in new user
* memory and creates the pointer tables from them, and puts their
- * addresses on the "stack", returning the new stack pointer value.
+ * addresses on the "stack", recording the new stack pointer value.
*/
-static unsigned long create_flat_tables(
- unsigned long pp,
- struct linux_binprm * bprm)
+static int create_flat_tables(struct linux_binprm * bprm, unsigned long arg_start)
{
- unsigned long *argv,*envp;
- unsigned long * sp;
- char * p = (char*)pp;
- int argc = bprm->argc;
- int envc = bprm->envc;
- char uninitialized_var(dummy);
-
- sp = (unsigned long *)p;
- sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
- sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN);
- argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
- envp = argv + (argc + 1);
+ char __user *p;
+ unsigned long __user *sp;
+ long i, len;
+ p = (char __user *)arg_start;
+ sp = (unsigned long __user *)current->mm->start_stack;
+
+ sp -= bprm->envc + 1;
+ sp -= bprm->argc + 1;
+ sp -= flat_argvp_envp_on_stack() ? 2 : 0;
+ sp -= 1; /* &argc */
+
+ current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
+ sp = (unsigned long __user *)current->mm->start_stack;
+
+ __put_user(bprm->argc, sp++);
if (flat_argvp_envp_on_stack()) {
- put_user((unsigned long) envp, sp + 2);
- put_user((unsigned long) argv, sp + 1);
- }
-
- put_user(argc, sp);
- current->mm->arg_start = (unsigned long) p;
- while (argc-->0) {
- put_user((unsigned long) p, argv++);
- do {
- get_user(dummy, p); p++;
- } while (dummy);
- }
- put_user((unsigned long) NULL, argv);
- current->mm->arg_end = current->mm->env_start = (unsigned long) p;
- while (envc-->0) {
- put_user((unsigned long)p, envp); envp++;
- do {
- get_user(dummy, p); p++;
- } while (dummy);
- }
- put_user((unsigned long) NULL, envp);
- current->mm->env_end = (unsigned long) p;
- return (unsigned long)sp;
+ unsigned long argv, envp;
+ argv = (unsigned long)(sp + 2);
+ envp = (unsigned long)(sp + 2 + bprm->argc + 1);
+ __put_user(argv, sp++);
+ __put_user(envp, sp++);
+ }
+
+ current->mm->arg_start = (unsigned long)p;
+ for (i = bprm->argc; i > 0; i--) {
+ __put_user((unsigned long)p, sp++);
+ len = strnlen_user(p, MAX_ARG_STRLEN);
+ if (!len || len > MAX_ARG_STRLEN)
+ return -EINVAL;
+ p += len;
+ }
+ __put_user(0, sp++);
+ current->mm->arg_end = (unsigned long)p;
+
+ current->mm->env_start = (unsigned long) p;
+ for (i = bprm->envc; i > 0; i--) {
+ __put_user((unsigned long)p, sp++);
+ len = strnlen_user(p, MAX_ARG_STRLEN);
+ if (!len || len > MAX_ARG_STRLEN)
+ return -EINVAL;
+ p += len;
+ }
+ __put_user(0, sp++);
+ current->mm->env_end = (unsigned long)p;
+
+ return 0;
}
/****************************************************************************/
@@ -854,7 +862,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
{
struct lib_info libinfo;
struct pt_regs *regs = current_pt_regs();
- unsigned long sp, stack_len;
+ unsigned long stack_len;
unsigned long start_addr;
int res;
int i, j;
@@ -868,11 +876,10 @@ static int load_flat_binary(struct linux_binprm * bprm)
* pedantic and include space for the argv/envp array as it may have
* a lot of entries.
*/
-#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
- stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
- stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
- stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
- stack_len += FLAT_STACK_ALIGN - 1; /* reserve for upcoming alignment */
+ stack_len = PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+ stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
+ stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
+ stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
res = load_flat_file(bprm, &libinfo, 0, &stack_len);
if (res < 0)
@@ -890,16 +897,18 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
- sp = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
- DBG_FLT("sp=%lx\n", sp);
+ /* Stash our initial stack pointer into the mm structure */
+ current->mm->start_stack =
+ ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
+ DBG_FLT("sp=%lx\n", current->mm->start_stack);
/* copy the arg pages onto the stack */
- res = transfer_args_to_stack(bprm, &sp);
+ res = transfer_args_to_stack(bprm, ¤t->mm->start_stack);
+ if (!res)
+ res = create_flat_tables(bprm, current->mm->start_stack);
if (res)
return res;
- sp = create_flat_tables(sp, bprm);
-
/* Fake some return addresses to ensure the call chain will
* initialise library in order for us. We are required to call
* lib 1 first, then 2, ... and finally the main program (id 0).
@@ -910,14 +919,14 @@ static int load_flat_binary(struct linux_binprm * bprm)
for (i = MAX_SHARED_LIBS-1; i>0; i--) {
if (libinfo.lib_list[i].loaded) {
/* Push previos first to call address */
- --sp; put_user(start_addr, (unsigned long *)sp);
+ unsigned long __user *sp;
+ current->mm->start_stack -= sizeof(unsigned long);
+ sp = (unsigned long __user *)current->mm->start_stack;
+ __put_user(start_addr, sp);
start_addr = libinfo.lib_list[i].entry;
}
}
#endif
-
- /* Stash our initial stack pointer into the mm structure */
- current->mm->start_stack = sp;
#ifdef FLAT_PLAT_INIT
FLAT_PLAT_INIT(regs);
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 05/10] binfmt_flat: use proper user space accessors with relocs processing code
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (3 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 04/10] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 22:21 ` kbuild test robot
2016-07-12 21:27 ` [PATCH 06/10] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
` (4 subsequent siblings)
9 siblings, 1 reply; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Relocs are fixed up in place in user space memory. The appropriate
accessors are required for this code to work with an active MMU.
Only those architectures with trivial architecture-specific handlers are
covered by this patch. Incidentally, those NOMMU architectures that can
also have a MMU are amongst the trivial ones so it should be fine.
---
arch/arm/include/asm/flat.h | 5 +++--
arch/m68k/include/asm/flat.h | 5 +++--
arch/sh/include/asm/flat.h | 5 +++--
arch/xtensa/include/asm/flat.h | 5 +++--
fs/binfmt_flat.c | 31 +++++++++++++++++++------------
5 files changed, 31 insertions(+), 20 deletions(-)
diff --git a/arch/arm/include/asm/flat.h b/arch/arm/include/asm/flat.h
index e847d23351..acf1d14b89 100644
--- a/arch/arm/include/asm/flat.h
+++ b/arch/arm/include/asm/flat.h
@@ -8,8 +8,9 @@
#define flat_argvp_envp_on_stack() 1
#define flat_old_ram_flag(flags) (flags)
#define flat_reloc_valid(reloc, size) ((reloc) <= (size))
-#define flat_get_addr_from_rp(rp, relval, flags, persistent) ((void)persistent,get_unaligned(rp))
-#define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp)
+#define flat_get_addr_from_rp(rp, relval, flags, persistent) \
+ ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
+#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
#define flat_get_relocate_addr(rel) (rel)
#define flat_set_persistent(relval, p) 0
diff --git a/arch/m68k/include/asm/flat.h b/arch/m68k/include/asm/flat.h
index f9454b89a5..f3f592d03e 100644
--- a/arch/m68k/include/asm/flat.h
+++ b/arch/m68k/include/asm/flat.h
@@ -8,8 +8,9 @@
#define flat_argvp_envp_on_stack() 1
#define flat_old_ram_flag(flags) (flags)
#define flat_reloc_valid(reloc, size) ((reloc) <= (size))
-#define flat_get_addr_from_rp(rp, relval, flags, p) get_unaligned(rp)
-#define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp)
+#define flat_get_addr_from_rp(rp, relval, flags, p) \
+ ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
+#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
#define flat_get_relocate_addr(rel) (rel)
static inline int flat_set_persistent(unsigned long relval,
diff --git a/arch/sh/include/asm/flat.h b/arch/sh/include/asm/flat.h
index 5d84df5e27..0f4f49ed6b 100644
--- a/arch/sh/include/asm/flat.h
+++ b/arch/sh/include/asm/flat.h
@@ -15,8 +15,9 @@
#define flat_argvp_envp_on_stack() 0
#define flat_old_ram_flag(flags) (flags)
#define flat_reloc_valid(reloc, size) ((reloc) <= (size))
-#define flat_get_addr_from_rp(rp, relval, flags, p) get_unaligned(rp)
-#define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp)
+#define flat_get_addr_from_rp(rp, relval, flags, p) \
+ ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
+#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
#define flat_get_relocate_addr(rel) (rel)
#define flat_set_persistent(relval, p) ({ (void)p; 0; })
diff --git a/arch/xtensa/include/asm/flat.h b/arch/xtensa/include/asm/flat.h
index 94c44abf15..fffad219af 100644
--- a/arch/xtensa/include/asm/flat.h
+++ b/arch/xtensa/include/asm/flat.h
@@ -4,8 +4,9 @@
#define flat_argvp_envp_on_stack() 0
#define flat_old_ram_flag(flags) (flags)
#define flat_reloc_valid(reloc, size) ((reloc) <= (size))
-#define flat_get_addr_from_rp(rp, relval, flags, p) get_unaligned(rp)
-#define flat_put_addr_at_rp(rp, val, relval ) put_unaligned(val, rp)
+#define flat_get_addr_from_rp(rp, relval, flags, p) \
+ ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
+#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
#define flat_get_relocate_addr(rel) (rel)
#define flat_set_persistent(relval, p) 0
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 9538901fe8..fc0ee3ed5d 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -438,7 +438,7 @@ static int load_flat_file(struct linux_binprm * bprm,
unsigned long textpos, datapos, realdatastart;
unsigned long text_len, data_len, bss_len, stack_len, full_data, flags;
unsigned long len, memp, memp_size, extra, rlim;
- unsigned long *reloc, *rp;
+ unsigned long __user *reloc, *rp;
struct inode *inode;
int i, rev, relocs;
loff_t fpos;
@@ -600,7 +600,7 @@ static int load_flat_file(struct linux_binprm * bprm,
goto err;
}
- reloc = (unsigned long *)
+ reloc = (unsigned long __user *)
(datapos + (ntohl(hdr->reloc_start) - text_len));
memp = realdatastart;
memp_size = len;
@@ -625,7 +625,7 @@ static int load_flat_file(struct linux_binprm * bprm,
MAX_SHARED_LIBS * sizeof(unsigned long),
FLAT_DATA_ALIGN);
- reloc = (unsigned long *)
+ reloc = (unsigned long __user *)
(datapos + (ntohl(hdr->reloc_start) - text_len));
memp = textpos;
memp_size = len;
@@ -718,15 +718,20 @@ static int load_flat_file(struct linux_binprm * bprm,
* image.
*/
if (flags & FLAT_FLAG_GOTPIC) {
- for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
- unsigned long addr;
- if (*rp) {
- addr = calc_reloc(*rp, libinfo, id, 0);
+ for (rp = (unsigned long __user *)datapos; ; rp++) {
+ unsigned long addr, rp_val;
+ if (get_user(rp_val, rp))
+ return -EFAULT;
+ if (rp_val == 0xffffffff)
+ break;
+ if (rp_val) {
+ addr = calc_reloc(rp_val, libinfo, id, 0);
if (addr == RELOC_FAILED) {
ret = -ENOEXEC;
goto err;
}
- *rp = addr;
+ if (put_user(addr, rp))
+ return -EFAULT;
}
}
}
@@ -743,19 +748,21 @@ static int load_flat_file(struct linux_binprm * bprm,
* __start to address 4 so that is okay).
*/
if (rev > OLD_FLAT_VERSION) {
- unsigned long persistent = 0;
+ unsigned long __maybe_unused persistent = 0;
for (i=0; i < relocs; i++) {
unsigned long addr, relval;
/* Get the address of the pointer to be
relocated (of course, the address has to be
relocated first). */
- relval = ntohl(reloc[i]);
+ if (get_user(relval, reloc + i))
+ return -EFAULT;
+ relval = ntohl(relval);
if (flat_set_persistent (relval, &persistent))
continue;
addr = flat_get_relocate_addr(relval);
- rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
- if (rp == (unsigned long *)RELOC_FAILED) {
+ rp = (unsigned long __user *)calc_reloc(addr, libinfo, id, 1);
+ if (rp == (unsigned long __user *)RELOC_FAILED) {
ret = -ENOEXEC;
goto err;
}
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH 05/10] binfmt_flat: use proper user space accessors with relocs processing code
2016-07-12 21:27 ` [PATCH 05/10] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
@ 2016-07-12 22:21 ` kbuild test robot
0 siblings, 0 replies; 12+ messages in thread
From: kbuild test robot @ 2016-07-12 22:21 UTC (permalink / raw)
To: Nicolas Pitre
Cc: kbuild-all, linux-fsdevel, linux-kernel, Alexander Viro,
David Howells, Greg Ungerer
[-- Attachment #1: Type: text/plain, Size: 3062 bytes --]
Hi,
[auto build test ERROR on arm/for-next]
[also build test ERROR on v4.7-rc7 next-20160712]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Nicolas-Pitre/binfmt_flat-assorted-cleanups/20160713-055609
base: http://repo.or.cz/linux-2.6/linux-2.6-arm.git for-next
config: sh-allyesconfig (attached as .config)
compiler: sh4-linux-gnu-gcc (Debian 5.3.1-8) 5.3.1 20160205
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sh
All error/warnings (new ones prefixed by >>):
In file included from include/linux/flat.h:12:0,
from fs/binfmt_flat.c:36:
fs/binfmt_flat.c: In function 'load_flat_file':
>> arch/sh/include/asm/flat.h:19:26: error: implicit declaration of function '__get_user_unaligned' [-Werror=implicit-function-declaration]
({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
^
>> fs/binfmt_flat.c:771:11: note: in expansion of macro 'flat_get_addr_from_rp'
addr = flat_get_addr_from_rp(rp, relval, flags,
^
>> arch/sh/include/asm/flat.h:20:46: error: implicit declaration of function '__put_user_unaligned' [-Werror=implicit-function-declaration]
#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
^
>> fs/binfmt_flat.c:787:5: note: in expansion of macro 'flat_put_addr_at_rp'
flat_put_addr_at_rp(rp, addr, relval);
^
>> arch/sh/include/asm/flat.h:19:26: warning: '__val' may be used uninitialized in this function [-Wmaybe-uninitialized]
({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
^
arch/sh/include/asm/flat.h:19:19: note: '__val' was declared here
({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
^
>> fs/binfmt_flat.c:771:11: note: in expansion of macro 'flat_get_addr_from_rp'
addr = flat_get_addr_from_rp(rp, relval, flags,
^
cc1: some warnings being treated as errors
vim +/__get_user_unaligned +19 arch/sh/include/asm/flat.h
13 #define __ASM_SH_FLAT_H
14
15 #define flat_argvp_envp_on_stack() 0
16 #define flat_old_ram_flag(flags) (flags)
17 #define flat_reloc_valid(reloc, size) ((reloc) <= (size))
18 #define flat_get_addr_from_rp(rp, relval, flags, p) \
> 19 ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; })
> 20 #define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp)
21 #define flat_get_relocate_addr(rel) (rel)
22 #define flat_set_persistent(relval, p) ({ (void)p; 0; })
23
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 40227 bytes --]
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 06/10] binfmt_flat: use proper user space accessors with old relocs code
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (4 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 05/10] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 07/10] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
` (3 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index fc0ee3ed5d..c85f8f1239 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -394,38 +394,41 @@ static void old_reloc(unsigned long rl)
static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
#endif
flat_v2_reloc_t r;
- unsigned long *ptr;
+ unsigned long __user *ptr;
+ unsigned long val;
r.value = rl;
#if defined(CONFIG_COLDFIRE)
- ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
+ ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
#else
- ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
+ ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
#endif
+ __get_user(val, ptr);
#ifdef DEBUG
printk("Relocation of variable at DATASEG+%x "
"(address %p, currently %lx) into segment %s\n",
- r.reloc.offset, ptr, *ptr, segment[r.reloc.type]);
+ r.reloc.offset, ptr, val, segment[r.reloc.type]);
#endif
switch (r.reloc.type) {
case OLD_FLAT_RELOC_TYPE_TEXT:
- *ptr += current->mm->start_code;
+ val += current->mm->start_code;
break;
case OLD_FLAT_RELOC_TYPE_DATA:
- *ptr += current->mm->start_data;
+ val += current->mm->start_data;
break;
case OLD_FLAT_RELOC_TYPE_BSS:
- *ptr += current->mm->end_data;
+ val += current->mm->end_data;
break;
default:
printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
break;
}
+ __put_user(val, ptr);
#ifdef DEBUG
- printk("Relocation became %lx\n", *ptr);
+ printk("Relocation became %lx\n", val);
#endif
}
@@ -788,8 +791,13 @@ static int load_flat_file(struct linux_binprm * bprm,
}
}
} else {
- for (i=0; i < relocs; i++)
- old_reloc(ntohl(reloc[i]));
+ for (i=0; i < relocs; i++) {
+ unsigned long relval;
+ if (get_user(relval, reloc + i))
+ return -EFAULT;
+ relval = ntohl(relval);
+ old_reloc(relval);
+ }
}
flush_icache_range(start_code, end_code);
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 07/10] binfmt_flat: use clear_user() rather than memset() to clear .bss
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (5 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 06/10] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 08/10] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
` (2 subsequent siblings)
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
This is needed on systems with a MMU.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index c85f8f1239..e981e66bb5 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -803,10 +803,11 @@ static int load_flat_file(struct linux_binprm * bprm,
flush_icache_range(start_code, end_code);
/* zero the BSS, BRK and stack areas */
- memset((void*)(datapos + data_len), 0, bss_len +
+ if (clear_user((void __user *)(datapos + data_len), bss_len +
(memp + memp_size - stack_len - /* end brk */
libinfo->lib_list[id].start_brk) + /* start brk */
- stack_len);
+ stack_len))
+ return -EFAULT;
return 0;
err:
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 08/10] binfmt_flat: update libraries' data segment pointer with userspace accessors
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (6 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 07/10] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 09/10] binfmt_flat: add MMU-specific support Nicolas Pitre
2016-07-12 21:27 ` [PATCH 10/10] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
This is needed on systems with a MMU. This also gets rid of the
strangest C code I've seen lateli i.e. an integer indexed with a
pointer value within square brackets. That really looked backwards.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index e981e66bb5..3221ed9d7c 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -902,12 +902,19 @@ static int load_flat_binary(struct linux_binprm * bprm)
return res;
/* Update data segment pointers for all libraries */
- for (i=0; i<MAX_SHARED_LIBS; i++)
- if (libinfo.lib_list[i].loaded)
- for (j=0; j<MAX_SHARED_LIBS; j++)
- (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
- (libinfo.lib_list[j].loaded)?
- libinfo.lib_list[j].start_data:UNLOADED_LIB;
+ for (i=0; i<MAX_SHARED_LIBS; i++) {
+ if (!libinfo.lib_list[i].loaded)
+ continue;
+ for (j=0; j<MAX_SHARED_LIBS; j++) {
+ unsigned long val = libinfo.lib_list[j].loaded ?
+ libinfo.lib_list[j].start_data : UNLOADED_LIB;
+ unsigned long __user *p = (unsigned long __user *)
+ libinfo.lib_list[i].start_data;
+ p -= j + 1;
+ if (put_user(val, p))
+ return -EFAULT;
+ }
+ }
install_exec_creds(bprm);
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 09/10] binfmt_flat: add MMU-specific support
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (7 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 08/10] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
2016-07-12 21:27 ` [PATCH 10/10] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Not much else to do at this point.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/Kconfig.binfmt | 3 ++-
fs/binfmt_flat.c | 16 +++++++++++++---
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 72c03354c1..1faba6a755 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -89,7 +89,8 @@ config BINFMT_SCRIPT
config BINFMT_FLAT
bool "Kernel support for flat binaries"
- depends on !MMU && (!FRV || BROKEN)
+ depends on !MMU || ARM || M68K || SUPERH || XTENSA
+ depends on !FRV || BROKEN
help
Support uClinux FLAT format binaries.
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 3221ed9d7c..4cb0c4b6ae 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -546,7 +546,7 @@ static int load_flat_file(struct linux_binprm * bprm,
* case, and then the fully copied to RAM case which lumps
* it all together.
*/
- if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
+ if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
/*
* this should give us a ROM ptr, but if it doesn't we don't
* really care
@@ -687,7 +687,9 @@ static int load_flat_file(struct linux_binprm * bprm,
*/
current->mm->start_brk = datapos + data_len + bss_len;
current->mm->brk = (current->mm->start_brk + 3) & ~3;
+#ifndef CONFIG_MMU
current->mm->context.end_brk = memp + memp_size - stack_len;
+#endif
}
if (flags & FLAT_FLAG_KTRACE) {
@@ -878,7 +880,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
{
struct lib_info libinfo;
struct pt_regs *regs = current_pt_regs();
- unsigned long stack_len;
+ unsigned long stack_len = 0;
unsigned long start_addr;
int res;
int i, j;
@@ -892,7 +894,9 @@ static int load_flat_binary(struct linux_binprm * bprm)
* pedantic and include space for the argv/envp array as it may have
* a lot of entries.
*/
- stack_len = PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+#ifndef CONFIG_MMU
+ stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+#endif
stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
@@ -920,6 +924,11 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
+#ifdef CONFIG_MMU
+ res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
+ if (!res)
+ res = create_flat_tables(bprm, bprm->p);
+#else
/* Stash our initial stack pointer into the mm structure */
current->mm->start_stack =
((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
@@ -929,6 +938,7 @@ static int load_flat_binary(struct linux_binprm * bprm)
res = transfer_args_to_stack(bprm, ¤t->mm->start_stack);
if (!res)
res = create_flat_tables(bprm, current->mm->start_stack);
+#endif
if (res)
return res;
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 10/10] binfmt_flat: allow compressed flat binary format to work on MMU systems
2016-07-12 21:27 [PATCH 00/10] allow BFLT executables on systems with a MMU Nicolas Pitre
` (8 preceding siblings ...)
2016-07-12 21:27 ` [PATCH 09/10] binfmt_flat: add MMU-specific support Nicolas Pitre
@ 2016-07-12 21:27 ` Nicolas Pitre
9 siblings, 0 replies; 12+ messages in thread
From: Nicolas Pitre @ 2016-07-12 21:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Let's take the simple and obvious approach by decompressing the binary
into a kernel buffer and then copying it to user space. Those who are
looking for more performance on a MMU system are unlikely to choose this
executable format anyway.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 4cb0c4b6ae..24deae4dcb 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -35,6 +35,7 @@
#include <linux/init.h>
#include <linux/flat.h>
#include <linux/syscalls.h>
+#include <linux/vmalloc.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>
@@ -637,6 +638,7 @@ static int load_flat_file(struct linux_binprm * bprm,
* load it all in and treat it like a RAM load from now on
*/
if (flags & FLAT_FLAG_GZIP) {
+#ifndef CONFIG_MMU
result = decompress_exec(bprm, sizeof (struct flat_hdr),
(((char *) textpos) + sizeof (struct flat_hdr)),
(text_len + full_data
@@ -644,14 +646,52 @@ static int load_flat_file(struct linux_binprm * bprm,
0);
memmove((void *) datapos, (void *) realdatastart,
full_data);
+#else
+ /*
+ * This is used on MMU systems mainly for testing.
+ * Let's use a kernel buffer to simplify things.
+ */
+ long unz_text_len = text_len - sizeof(struct flat_hdr);
+ long unz_len = unz_text_len + full_data;
+ char *unz_data = vmalloc(unz_len);
+ if (!unz_data) {
+ result = -ENOMEM;
+ } else {
+ result = decompress_exec(bprm, sizeof(struct flat_hdr),
+ unz_data, unz_len, 0);
+ if (result == 0 &&
+ (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
+ unz_data, unz_text_len) ||
+ copy_to_user((void __user *)datapos,
+ unz_data + unz_text_len, full_data)))
+ result = -EFAULT;
+ vfree(unz_data);
+ }
+#endif
} else if (flags & FLAT_FLAG_GZDATA) {
result = read_code(bprm->file, textpos, 0, text_len);
- if (!IS_ERR_VALUE(result))
+ if (!IS_ERR_VALUE(result)) {
+#ifndef CONFIG_MMU
result = decompress_exec(bprm, text_len, (char *) datapos,
full_data, 0);
+#else
+ char *unz_data = vmalloc(full_data);
+ if (!unz_data) {
+ result = -ENOMEM;
+ } else {
+ result = decompress_exec(bprm, text_len,
+ unz_data, full_data, 0);
+ if (result == 0 &&
+ copy_to_user((void __user *)datapos,
+ unz_data, full_data))
+ result = -EFAULT;
+ vfree(unz_data);
+ }
+#endif
+ }
}
else
-#endif
+#endif /* CONFIG_BINFMT_ZFLAT */
{
result = read_code(bprm->file, textpos, 0, text_len);
if (!IS_ERR_VALUE(result))
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread