* [PATCH v3 01/12] binfmt_flat: assorted cleanups
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
` (10 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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] 16+ messages in thread* [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 01/12] binfmt_flat: assorted cleanups Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:30 ` Joe Perches
2016-07-20 4:20 ` [PATCH v3 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers Nicolas Pitre
` (9 subsequent siblings)
11 siblings, 1 reply; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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 | 118 ++++++++++++++++++++++++-------------------------------
1 file changed, 51 insertions(+), 67 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 085059d879..36f5bb6b2c 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -15,6 +15,8 @@
* JAN/99 -- coded full program relocation (gerg@snapgear.com)
*/
+#define pr_fmt(fmt) "BINFMT_FLAT: : " fmt
+
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/sched.h>
@@ -44,16 +46,6 @@
/****************************************************************************/
-#if 0
-#define DEBUG 1
-#endif
-
-#ifdef DEBUG
-#define DBG_FLT(a...) printk(a)
-#else
-#define DBG_FLT(a...)
-#endif
-
/*
* User data (data section and bss) needs to be aligned.
* We pick 0x20 here because it is the max value elf2flt has always
@@ -106,8 +98,8 @@ 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, cprm->siginfo->si_signo);
+ pr_warning("Process %s:%d received signr %d and should have core dumped\n",
+ current->comm, current->pid, cprm->siginfo->si_signo);
return(1);
}
@@ -190,17 +182,17 @@ static int decompress_exec(
loff_t fpos;
int ret, retval;
- DBG_FLT("decompress_exec(offset=%lx,buf=%p,len=%lx)\n",offset, dst, len);
+ pr_debug("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);
if (strm.workspace == NULL) {
- DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
+ pr_debug("no memory for decompress workspace\n");
return -ENOMEM;
}
buf = kmalloc(LBUFSIZE, GFP_KERNEL);
if (buf == NULL) {
- DBG_FLT("binfmt_flat: no memory for read buffer\n");
+ pr_debug("no memory for read buffer\n");
retval = -ENOMEM;
goto out_free;
}
@@ -218,25 +210,25 @@ static int decompress_exec(
/* Check minimum size -- gzip header */
if (ret < 10) {
- DBG_FLT("binfmt_flat: file too small?\n");
+ pr_debug("file too small?\n");
goto out_free_buf;
}
/* Check gzip magic number */
if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
- DBG_FLT("binfmt_flat: unknown compression magic?\n");
+ pr_debug("unknown compression magic?\n");
goto out_free_buf;
}
/* Check gzip method */
if (buf[2] != 8) {
- DBG_FLT("binfmt_flat: unknown compression method?\n");
+ pr_debug("unknown compression method?\n");
goto out_free_buf;
}
/* Check gzip flags */
if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
(buf[3] & RESERVED)) {
- DBG_FLT("binfmt_flat: unknown flags?\n");
+ pr_debug("unknown flags?\n");
goto out_free_buf;
}
@@ -244,7 +236,7 @@ static int decompress_exec(
if (buf[3] & EXTRA_FIELD) {
ret += 2 + buf[10] + (buf[11] << 8);
if (unlikely(LBUFSIZE <= ret)) {
- DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
+ pr_debug("buffer overflow (EXTRA)?\n");
goto out_free_buf;
}
}
@@ -252,7 +244,7 @@ static int decompress_exec(
while (ret < LBUFSIZE && buf[ret++] != 0)
;
if (unlikely(LBUFSIZE == ret)) {
- DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
+ pr_debug("buffer overflow (ORIG_NAME)?\n");
goto out_free_buf;
}
}
@@ -260,7 +252,7 @@ static int decompress_exec(
while (ret < LBUFSIZE && buf[ret++] != 0)
;
if (unlikely(LBUFSIZE == ret)) {
- DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
+ pr_debug("buffer overflow (COMMENT)?\n");
goto out_free_buf;
}
}
@@ -273,7 +265,7 @@ static int decompress_exec(
strm.total_out = 0;
if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
- DBG_FLT("binfmt_flat: zlib init failed?\n");
+ pr_debug("zlib init failed?\n");
goto out_free_buf;
}
@@ -290,7 +282,7 @@ static int decompress_exec(
}
if (ret < 0) {
- DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
+ pr_debug("decompression failed (%d), %s\n",
ret, strm.msg);
goto out_zlib;
}
@@ -327,24 +319,23 @@ calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
r &= 0x00ffffff; /* Trim ID off here */
}
if (id >= MAX_SHARED_LIBS) {
- printk("BINFMT_FLAT: reference 0x%x to shared library %d",
- (unsigned) r, id);
+ pr_err("reference 0x%lx to shared library %d", r, id);
goto failed;
}
if (curid != id) {
if (internalp) {
- printk("BINFMT_FLAT: reloc address 0x%x not in same module "
- "(%d != %d)", (unsigned) r, curid, id);
+ pr_err("reloc address 0x%lx not in same module "
+ "(%d != %d)", r, curid, id);
goto failed;
} else if ( ! p->lib_list[id].loaded &&
load_flat_shared_library(id, p) < 0) {
- printk("BINFMT_FLAT: failed to load library %d", id);
+ pr_err("failed to load library %d", id);
goto failed;
}
/* Check versioning information (i.e. time stamps) */
if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
p->lib_list[curid].build_date < p->lib_list[id].build_date) {
- printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
+ pr_err("library %d is younger than %d", id, curid);
goto failed;
}
}
@@ -358,7 +349,7 @@ 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%lx (0 - 0x%lx/0x%lx)",
+ pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
r, start_brk-start_data+text_len, text_len);
goto failed;
}
@@ -372,7 +363,7 @@ calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
return(addr);
failed:
- printk(", killing %s!\n", current->comm);
+ pr_cont(", killing %s!\n", current->comm);
send_sig(SIGSEGV, current, 0);
return RELOC_FAILED;
@@ -382,9 +373,7 @@ failed:
static void old_reloc(unsigned long rl)
{
-#ifdef DEBUG
static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
-#endif
flat_v2_reloc_t r;
unsigned long *ptr;
@@ -395,11 +384,9 @@ static void old_reloc(unsigned long rl)
ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
#endif
-#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]);
-#endif
+ pr_debug("Relocation of variable at DATASEG+%x "
+ "(address %p, currently %lx) into segment %s\n",
+ r.reloc.offset, ptr, *ptr, segment[r.reloc.type]);
switch (r.reloc.type) {
case OLD_FLAT_RELOC_TYPE_TEXT:
@@ -412,13 +399,11 @@ static void old_reloc(unsigned long rl)
*ptr += current->mm->end_data;
break;
default:
- printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
+ pr_err("Unknown relocation type=%x\n", r.reloc.type);
break;
}
-#ifdef DEBUG
- printk("Relocation became %lx\n", *ptr);
-#endif
+ pr_debug("Relocation became %lx\n", *ptr);
}
/****************************************************************************/
@@ -467,20 +452,19 @@ static int load_flat_file(struct linux_binprm * bprm,
}
if (flags & FLAT_FLAG_KTRACE)
- printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
+ pr_info("Loading file: %s\n", bprm->filename);
if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
- printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
- "0x%lx and 0x%lx)\n",
- rev, FLAT_VERSION, OLD_FLAT_VERSION);
+ pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
+ rev, FLAT_VERSION, OLD_FLAT_VERSION);
ret = -ENOEXEC;
goto err;
}
/* 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%lx\n",
- FLAT_VERSION);
+ pr_err("shared libraries are not available before rev 0x%lx\n",
+ FLAT_VERSION);
ret = -ENOEXEC;
goto err;
}
@@ -494,7 +478,7 @@ static int load_flat_file(struct linux_binprm * bprm,
#ifndef CONFIG_BINFMT_ZFLAT
if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
- printk("Support for ZFLAT executables is not enabled.\n");
+ pr_err("Support for ZFLAT executables is not enabled.\n");
ret = -ENOEXEC;
goto err;
}
@@ -540,7 +524,7 @@ static int load_flat_file(struct linux_binprm * bprm,
* this should give us a ROM ptr, but if it doesn't we don't
* really care
*/
- DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
+ pr_debug("ROM mapping of file (we hope)\n");
textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
MAP_PRIVATE|MAP_EXECUTABLE, 0);
@@ -548,7 +532,7 @@ static int load_flat_file(struct linux_binprm * bprm,
ret = textpos;
if (!textpos)
ret = -ENOMEM;
- printk("Unable to mmap process text, errno %d\n", ret);
+ pr_err("Unable to mmap process text, errno %d\n", ret);
goto err;
}
@@ -561,7 +545,7 @@ static int load_flat_file(struct linux_binprm * bprm,
ret = realdatastart;
if (!realdatastart)
ret = -ENOMEM;
- printk("Unable to allocate RAM for process data, "
+ pr_err("Unable to allocate RAM for process data, "
"errno %d\n", ret);
vm_munmap(textpos, text_len);
goto err;
@@ -570,8 +554,8 @@ static int load_flat_file(struct linux_binprm * bprm,
MAX_SHARED_LIBS * sizeof(unsigned long),
FLAT_DATA_ALIGN);
- DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%ld bytes): %lx\n",
- data_len + bss_len + stack_len, datapos);
+ pr_debug("Allocated data+bss+stack (%ld bytes): %lx\n",
+ data_len + bss_len + stack_len, datapos);
fpos = ntohl(hdr->data_start);
#ifdef CONFIG_BINFMT_ZFLAT
@@ -586,7 +570,7 @@ static int load_flat_file(struct linux_binprm * bprm,
}
if (IS_ERR_VALUE(result)) {
ret = result;
- printk("Unable to read data+bss, errno %d\n", ret);
+ pr_err("Unable to read data+bss, errno %d\n", ret);
vm_munmap(textpos, text_len);
vm_munmap(realdatastart, len);
goto err;
@@ -607,7 +591,7 @@ static int load_flat_file(struct linux_binprm * bprm,
ret = textpos;
if (!textpos)
ret = -ENOMEM;
- printk("Unable to allocate RAM for process text/data, "
+ pr_err("Unable to allocate RAM for process text/data, "
"errno %d\n", ret);
goto err;
}
@@ -650,7 +634,7 @@ static int load_flat_file(struct linux_binprm * bprm,
}
if (IS_ERR_VALUE(result)) {
ret = result;
- printk("Unable to read code+data+bss, errno %d\n", ret);
+ pr_err("Unable to read code+data+bss, errno %d\n", ret);
vm_munmap(textpos, text_len + data_len + extra +
MAX_SHARED_LIBS * sizeof(unsigned long));
goto err;
@@ -680,12 +664,12 @@ static int load_flat_file(struct linux_binprm * bprm,
}
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);
+ pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
+ textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
+ pr_info("%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 */
@@ -893,7 +877,7 @@ 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=%lx\n", p);
+ pr_debug("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--)
@@ -925,8 +909,8 @@ static int load_flat_binary(struct linux_binprm * bprm)
FLAT_PLAT_INIT(regs);
#endif
- DBG_FLT("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
- regs, start_addr, current->mm->start_stack);
+ pr_debug("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] 16+ messages in thread* Re: [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form
2016-07-20 4:20 ` [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
@ 2016-07-20 4:30 ` Joe Perches
2016-07-20 5:05 ` Nicolas Pitre
0 siblings, 1 reply; 16+ messages in thread
From: Joe Perches @ 2016-07-20 4:30 UTC (permalink / raw)
To: Nicolas Pitre, linux-fsdevel, linux-kernel
Cc: Alexander Viro, David Howells, Greg Ungerer
On Wed, 2016-07-20 at 00:20 -0400, Nicolas Pitre wrote:
> diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
[]
> @@ -15,6 +15,8 @@
> * JAN/99 -- coded full program relocation (gerg@snapgear.com)
> */
>
> +#define pr_fmt(fmt) "BINFMT_FLAT: : " fmt
Why the double colon?
Much more common would be
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> @@ -106,8 +98,8 @@ 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, cprm->siginfo->si_signo);
> + pr_warning("Process %s:%d received signr %d and should have core dumped\n",
> + current->comm, current->pid, cprm->siginfo->si_signo);
Prefer pr_warn
> return(1);
> }
>
> @@ -190,17 +182,17 @@ static int decompress_exec(
> loff_t fpos;
> int ret, retval;
>
> - DBG_FLT("decompress_exec(offset=%lx,buf=%p,len=%lx)\n",offset, dst, len);
> + pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n",offset, dst, len);
Generally unnecessary as the function tracer works well
>
> memset(&strm, 0, sizeof(strm));
> strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
> if (strm.workspace == NULL) {
> - DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
> + pr_debug("no memory for decompress workspace\n");
> return -ENOMEM;
> }
> buf = kmalloc(LBUFSIZE, GFP_KERNEL);
> if (buf == NULL) {
> - DBG_FLT("binfmt_flat: no memory for read buffer\n");
> + pr_debug("no memory for read buffer\n");
Unnecessary OOM messages as allocs do a stack dump
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form
2016-07-20 4:30 ` Joe Perches
@ 2016-07-20 5:05 ` Nicolas Pitre
0 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 5:05 UTC (permalink / raw)
To: Joe Perches
Cc: linux-fsdevel, linux-kernel, Alexander Viro, David Howells, Greg Ungerer
[-- Attachment #1: Type: text/plain, Size: 2219 bytes --]
On Tue, 19 Jul 2016, Joe Perches wrote:
> On Wed, 2016-07-20 at 00:20 -0400, Nicolas Pitre wrote:
> > diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
> []
> > @@ -15,6 +15,8 @@
> > * JAN/99 -- coded full program relocation (gerg@snapgear.com)
> > */
> >
> > +#define pr_fmt(fmt) "BINFMT_FLAT: : " fmt
>
> Why the double colon?
Go figure.
> Much more common would be
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Sure. I used the all-caps version as that's what most former printk's
used. But if you say KBUILD_MODNAME is more common then I have no issue
with that.
>
> > @@ -106,8 +98,8 @@ 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, cprm->siginfo->si_signo);
> > + pr_warning("Process %s:%d received signr %d and should have core dumped\n",
> > + current->comm, current->pid, cprm->siginfo->si_signo);
>
> Prefer pr_warn
OK.
Updated in my repo and pushed out.
> > return(1);
> > }
> >
> > @@ -190,17 +182,17 @@ static int decompress_exec(
> > loff_t fpos;
> > int ret, retval;
> >
> > - DBG_FLT("decompress_exec(offset=%lx,buf=%p,len=%lx)\n",offset, dst, len);
> > + pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n",offset, dst, len);
>
> Generally unnecessary as the function tracer works well
Not necessarily on uClinux where you might not aford it.
And this patch is about converting existing printk()'s so if some of
them should be removed then it would be best to do that separately.
> > memset(&strm, 0, sizeof(strm));
> > strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
> > if (strm.workspace == NULL) {
> > - DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
> > + pr_debug("no memory for decompress workspace\n");
> > return -ENOMEM;
> > }
> > buf = kmalloc(LBUFSIZE, GFP_KERNEL);
> > if (buf == NULL) {
> > - DBG_FLT("binfmt_flat: no memory for read buffer\n");
> > + pr_debug("no memory for read buffer\n");
>
> Unnecessary OOM messages as allocs do a stack dump
Again this should probably be done separately.
Nicolas
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v3 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 01/12] binfmt_flat: assorted cleanups Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 02/12] binfmt_flat: convert printk invocations to their modern form Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 04/12] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
` (8 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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 | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 36f5bb6b2c..9c76d9a222 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -470,6 +470,17 @@ static int load_flat_file(struct linux_binprm * bprm,
}
/*
+ * Make sure the header params are sane.
+ * 28 bits (256 MB) is way more than reasonable in this case.
+ * If some top bits are set we have probable binary corruption.
+ */
+ if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
+ pr_err("bad header\n");
+ ret = -ENOEXEC;
+ goto err;
+ }
+
+ /*
* fix up the flags for the older format, there were all kinds
* of endian hacks, this only works for the simple cases
*/
--
2.7.4
^ permalink raw reply related [flat|nested] 16+ messages in thread* [PATCH v3 04/12] elf_fdpic_transfer_args_to_stack(): make it generic
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (2 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 05/12] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
` (7 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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] 16+ messages in thread* [PATCH v3 05/12] binfmt_flat: use generic transfer_args_to_stack()
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (3 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 04/12] elf_fdpic_transfer_args_to_stack(): make it generic Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 06/12] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
` (6 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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 9c76d9a222..fdd33ba9e3 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -849,10 +849,8 @@ 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;
@@ -887,15 +885,15 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
- p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
- pr_debug("p=%lx\n", p);
+ sp = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
+ pr_debug("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
@@ -907,14 +905,14 @@ 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] 16+ messages in thread* [PATCH v3 06/12] binfmt_flat: clean up create_flat_tables() and stack accesses
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (4 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 05/12] binfmt_flat: use generic transfer_args_to_stack() Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 07/12] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
` (5 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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 fdd33ba9e3..90a10d7149 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -107,50 +107,58 @@ 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;
}
/****************************************************************************/
@@ -849,7 +857,7 @@ 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;
@@ -863,11 +871,10 @@ 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)
@@ -885,16 +892,18 @@ static int load_flat_binary(struct linux_binprm * bprm)
set_binfmt(&flat_format);
- sp = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
- pr_debug("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;
+ pr_debug("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).
@@ -905,14 +914,14 @@ 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] 16+ messages in thread* [PATCH v3 07/12] binfmt_flat: use proper user space accessors with relocs processing code
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (5 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 06/12] binfmt_flat: clean up create_flat_tables() and stack accesses Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 08/12] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
` (4 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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.
The architecture specific handlers for ARM and M68K are also
covered. SuperH and Xtensa are left out as they doesn't implement
__get_user_unaligned() and __put_user_unaligned() yet. The other
architectures that use BFLT don't have any MMU.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
---
arch/arm/include/asm/flat.h | 5 +++--
arch/m68k/include/asm/flat.h | 5 +++--
fs/binfmt_flat.c | 31 +++++++++++++++++++------------
3 files changed, 25 insertions(+), 16 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/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 90a10d7149..34f815540e 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -423,7 +423,7 @@ 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;
@@ -595,7 +595,7 @@ 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;
@@ -620,7 +620,7 @@ 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;
@@ -713,15 +713,20 @@ 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;
}
}
}
@@ -738,19 +743,21 @@ 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] 16+ messages in thread* [PATCH v3 08/12] binfmt_flat: use proper user space accessors with old relocs code
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (6 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 07/12] binfmt_flat: use proper user space accessors with relocs processing code Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
` (3 subsequent siblings)
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
---
fs/binfmt_flat.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 34f815540e..28fc272d9a 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -383,36 +383,39 @@ static void old_reloc(unsigned long rl)
{
static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
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);
pr_debug("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]);
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:
pr_err("Unknown relocation type=%x\n", r.reloc.type);
break;
}
+ __put_user(val, ptr);
- pr_debug("Relocation became %lx\n", *ptr);
-}
+ pr_debug("Relocation became %lx\n", val);
+}
/****************************************************************************/
@@ -783,8 +786,13 @@ 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] 16+ messages in thread* [PATCH v3 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (7 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 08/12] binfmt_flat: use proper user space accessors with old relocs code Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 7:15 ` Greg Ungerer
2016-07-20 4:20 ` [PATCH v3 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
` (2 subsequent siblings)
11 siblings, 1 reply; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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 28fc272d9a..0d89830f76 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -798,10 +798,11 @@ 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] 16+ messages in thread* Re: [PATCH v3 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss
2016-07-20 4:20 ` [PATCH v3 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
@ 2016-07-20 7:15 ` Greg Ungerer
0 siblings, 0 replies; 16+ messages in thread
From: Greg Ungerer @ 2016-07-20 7:15 UTC (permalink / raw)
To: Nicolas Pitre, linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells
On 20/07/16 14:20, Nicolas Pitre wrote:
> This is needed on systems with a MMU.
>
> Signed-off-by: Nicolas Pitre <nico@linaro.org>
> Reviewed-by: Greg Ungerer <gerg@linux-m68k.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 28fc272d9a..0d89830f76 100644
> --- a/fs/binfmt_flat.c
> +++ b/fs/binfmt_flat.c
> @@ -798,10 +798,11 @@ 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 +
nit: this adds a trailing white space ^
(Yes, the memset did have this before as well)
Regards
Greg
> (memp + memp_size - stack_len - /* end brk */
> libinfo->lib_list[id].start_brk) + /* start brk */
> - stack_len);
> + stack_len))
> + return -EFAULT;
>
> return 0;
> err:
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* [PATCH v3 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (8 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 09/12] binfmt_flat: use clear_user() rather than memset() to clear .bss Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 11/12] binfmt_flat: add MMU-specific support Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 12/12] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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 0d89830f76..fef94aaa36 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -897,12 +897,19 @@ 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] 16+ messages in thread* [PATCH v3 11/12] binfmt_flat: add MMU-specific support
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (9 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 10/12] binfmt_flat: update libraries' data segment pointer with userspace accessors Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
2016-07-20 4:20 ` [PATCH v3 12/12] binfmt_flat: allow compressed flat binary format to work on MMU systems Nicolas Pitre
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel; +Cc: Alexander Viro, David Howells, Greg Ungerer
Not much else to do at this point except for the different stack setups.
SuperH and Xtensa could be added to the allowed list if they implement
__put_user_unaligned() and __get_user_unaligned().
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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..4c09d93d95 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
+ depends on !FRV || BROKEN
help
Support uClinux FLAT format binaries.
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index fef94aaa36..d04188267a 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -541,7 +541,7 @@ 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
@@ -682,7 +682,9 @@ 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) {
@@ -873,7 +875,7 @@ 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;
@@ -887,7 +889,9 @@ 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);
@@ -915,6 +919,11 @@ 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;
@@ -924,6 +933,7 @@ 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] 16+ messages in thread* [PATCH v3 12/12] binfmt_flat: allow compressed flat binary format to work on MMU systems
2016-07-20 4:20 [PATCH v3 00/12] allow BFLT executables on systems with a MMU Nicolas Pitre
` (10 preceding siblings ...)
2016-07-20 4:20 ` [PATCH v3 11/12] binfmt_flat: add MMU-specific support Nicolas Pitre
@ 2016-07-20 4:20 ` Nicolas Pitre
11 siblings, 0 replies; 16+ messages in thread
From: Nicolas Pitre @ 2016-07-20 4:20 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 top performance on an MMU system are unlikely to choose this
executable format anyway.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.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 d04188267a..8dac70921b 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -37,6 +37,7 @@
#include <linux/init.h>
#include <linux/flat.h>
#include <linux/syscalls.h>
+#include <linux/vmalloc.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>
@@ -632,6 +633,7 @@ 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
@@ -639,14 +641,52 @@ 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] 16+ messages in thread