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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-10 21:42:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-10 21:42:03 -0700
commit398364a35daed7361e76c3666fb9a97792edce09 (patch)
tree7a63b4df27d2dc75da8549499c79805128183f28 /fs
parentd2b6b4c832f7e3067709e8d4970b7b82b44419ac (diff)
parentad97f9df0fee4ddc9ef056dda4dcbc6630d9f972 (diff)
downloadlinux-398364a35daed7361e76c3666fb9a97792edce09.tar.bz2
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
Pull m68nommu updates from Greg Ungerer: "A series of cleanups for the FLAT format binary loader, binfmt_flat, from Christoph. The end goal is to support no-MMU on RISC-V, and the last patch enables that" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: riscv: add binfmt_flat support binfmt_flat: don't offset the data start binfmt_flat: move the MAX_SHARED_LIBS definition to binfmt_flat.c binfmt_flat: remove the persistent argument from flat_get_addr_from_rp binfmt_flat: provide an asm-generic/flat.h binfmt_flat: make support for old format binaries optional binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option binfmt_flat: add endianess annotations binfmt_flat: use fixed size type for the on-disk format binfmt_flat: consolidate two version of flat_v2_reloc_t binfmt_flat: remove the unused OLD_FLAT_FLAG_RAM definition binfmt_flat: remove the uapi <linux/flat.h> header binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable binfmt_flat: remove flat_old_ram_flag binfmt_flat: provide a default version of flat_get_relocate_addr binfmt_flat: remove flat_set_persistent binfmt_flat: remove flat_reloc_valid
Diffstat (limited to 'fs')
-rw-r--r--fs/Kconfig.binfmt18
-rw-r--r--fs/binfmt_flat.c99
2 files changed, 79 insertions, 38 deletions
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index f87ddd1b6d72..62dc4f577ba1 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -91,12 +91,28 @@ config BINFMT_SCRIPT
Most systems will not boot if you say M or N here. If unsure, say Y.
+config ARCH_HAS_BINFMT_FLAT
+ bool
+
config BINFMT_FLAT
bool "Kernel support for flat binaries"
- depends on !MMU || ARM || M68K
+ depends on ARCH_HAS_BINFMT_FLAT
help
Support uClinux FLAT format binaries.
+config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+ bool
+
+config BINFMT_FLAT_OLD_ALWAYS_RAM
+ bool
+
+config BINFMT_FLAT_OLD
+ bool "Enable support for very old legacy flat binaries"
+ depends on BINFMT_FLAT
+ help
+ Support decade old uClinux FLAT format binaries. Unless you know
+ you have some of those say N here.
+
config BINFMT_ZFLAT
bool "Enable ZFLAT support"
depends on BINFMT_FLAT
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index e4b59e76afb0..8c6b50f34466 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -42,6 +42,11 @@
#include <asm/unaligned.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
+#include <asm/flat.h>
+
+#ifndef flat_get_relocate_addr
+#define flat_get_relocate_addr(rel) (rel)
+#endif
/****************************************************************************/
@@ -63,6 +68,12 @@
#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
+#ifdef CONFIG_BINFMT_SHARED_FLAT
+#define MAX_SHARED_LIBS (4)
+#else
+#define MAX_SHARED_LIBS (1)
+#endif
+
struct lib_info {
struct {
unsigned long start_code; /* Start of text segment */
@@ -120,14 +131,15 @@ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start
sp -= bprm->envc + 1;
sp -= bprm->argc + 1;
- sp -= flat_argvp_envp_on_stack() ? 2 : 0;
+ if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
+ sp -= 2; /* argvp + envp */
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()) {
+ if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
unsigned long argv, envp;
argv = (unsigned long)(sp + 2);
envp = (unsigned long)(sp + 2 + bprm->argc + 1);
@@ -345,7 +357,7 @@ calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
start_code = p->lib_list[id].start_code;
text_len = p->lib_list[id].text_len;
- if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
+ if (r > start_brk - start_data + text_len) {
pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
r, start_brk-start_data+text_len, text_len);
goto failed;
@@ -368,6 +380,7 @@ failed:
/****************************************************************************/
+#ifdef CONFIG_BINFMT_FLAT_OLD
static void old_reloc(unsigned long rl)
{
static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
@@ -405,6 +418,7 @@ static void old_reloc(unsigned long rl)
pr_debug("Relocation became %lx\n", val);
}
+#endif /* CONFIG_BINFMT_FLAT_OLD */
/****************************************************************************/
@@ -415,7 +429,8 @@ static int load_flat_file(struct linux_binprm *bprm,
unsigned long textpos, datapos, realdatastart;
u32 text_len, data_len, bss_len, stack_len, full_data, flags;
unsigned long len, memp, memp_size, extra, rlim;
- u32 __user *reloc, *rp;
+ __be32 __user *reloc;
+ u32 __user *rp;
struct inode *inode;
int i, rev, relocs;
loff_t fpos;
@@ -454,6 +469,7 @@ static int load_flat_file(struct linux_binprm *bprm,
if (flags & FLAT_FLAG_KTRACE)
pr_info("Loading file: %s\n", bprm->filename);
+#ifdef CONFIG_BINFMT_FLAT_OLD
if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
rev, FLAT_VERSION, OLD_FLAT_VERSION);
@@ -470,6 +486,23 @@ static int load_flat_file(struct linux_binprm *bprm,
}
/*
+ * fix up the flags for the older format, there were all kinds
+ * of endian hacks, this only works for the simple cases
+ */
+ if (rev == OLD_FLAT_VERSION &&
+ (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
+ flags = FLAT_FLAG_RAM;
+
+#else /* CONFIG_BINFMT_FLAT_OLD */
+ if (rev != FLAT_VERSION) {
+ pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
+ rev, FLAT_VERSION);
+ ret = -ENOEXEC;
+ goto err;
+ }
+#endif /* !CONFIG_BINFMT_FLAT_OLD */
+
+ /*
* 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.
@@ -480,13 +513,6 @@ static int load_flat_file(struct linux_binprm *bprm,
goto err;
}
- /*
- * fix up the flags for the older format, there were all kinds
- * of endian hacks, this only works for the simple cases
- */
- if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
- flags = FLAT_FLAG_RAM;
-
#ifndef CONFIG_BINFMT_ZFLAT
if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
pr_err("Support for ZFLAT executables is not enabled.\n");
@@ -547,7 +573,7 @@ static int load_flat_file(struct linux_binprm *bprm,
goto err;
}
- len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
+ len = data_len + extra;
len = PAGE_ALIGN(len);
realdatastart = vm_mmap(NULL, 0, len,
PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
@@ -561,9 +587,7 @@ static int load_flat_file(struct linux_binprm *bprm,
vm_munmap(textpos, text_len);
goto err;
}
- datapos = ALIGN(realdatastart +
- MAX_SHARED_LIBS * sizeof(unsigned long),
- FLAT_DATA_ALIGN);
+ datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
data_len + bss_len + stack_len, datapos);
@@ -587,13 +611,13 @@ static int load_flat_file(struct linux_binprm *bprm,
goto err;
}
- reloc = (u32 __user *)
+ reloc = (__be32 __user *)
(datapos + (ntohl(hdr->reloc_start) - text_len));
memp = realdatastart;
memp_size = len;
} else {
- len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
+ len = text_len + data_len + extra;
len = PAGE_ALIGN(len);
textpos = vm_mmap(NULL, 0, len,
PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
@@ -608,11 +632,9 @@ static int load_flat_file(struct linux_binprm *bprm,
}
realdatastart = textpos + ntohl(hdr->data_start);
- datapos = ALIGN(realdatastart +
- MAX_SHARED_LIBS * sizeof(u32),
- FLAT_DATA_ALIGN);
+ datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN);
- reloc = (u32 __user *)
+ reloc = (__be32 __user *)
(datapos + (ntohl(hdr->reloc_start) - text_len));
memp = textpos;
memp_size = len;
@@ -627,8 +649,9 @@ static int load_flat_file(struct linux_binprm *bprm,
(text_len + full_data
- sizeof(struct flat_hdr)),
0);
- memmove((void *) datapos, (void *) realdatastart,
- full_data);
+ if (datapos != realdatastart)
+ memmove((void *)datapos, (void *)realdatastart,
+ full_data);
#else
/*
* This is used on MMU systems mainly for testing.
@@ -684,8 +707,7 @@ static int load_flat_file(struct linux_binprm *bprm,
if (IS_ERR_VALUE(result)) {
ret = result;
pr_err("Unable to read code+data+bss, errno %d\n", ret);
- vm_munmap(textpos, text_len + data_len + extra +
- MAX_SHARED_LIBS * sizeof(u32));
+ vm_munmap(textpos, text_len + data_len + extra);
goto err;
}
}
@@ -775,20 +797,18 @@ static int load_flat_file(struct linux_binprm *bprm,
* __start to address 4 so that is okay).
*/
if (rev > OLD_FLAT_VERSION) {
- u32 __maybe_unused persistent = 0;
for (i = 0; i < relocs; i++) {
u32 addr, relval;
+ __be32 tmp;
/*
* Get the address of the pointer to be
* relocated (of course, the address has to be
* relocated first).
*/
- if (get_user(relval, reloc + i))
+ if (get_user(tmp, reloc + i))
return -EFAULT;
- relval = ntohl(relval);
- if (flat_set_persistent(relval, &persistent))
- continue;
+ relval = ntohl(tmp);
addr = flat_get_relocate_addr(relval);
rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
if (rp == (u32 __user *)RELOC_FAILED) {
@@ -797,8 +817,7 @@ static int load_flat_file(struct linux_binprm *bprm,
}
/* Get the pointer's value. */
- ret = flat_get_addr_from_rp(rp, relval, flags,
- &addr, &persistent);
+ ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
if (unlikely(ret))
goto err;
@@ -807,8 +826,13 @@ static int load_flat_file(struct linux_binprm *bprm,
* Do the relocation. PIC relocs in the data section are
* already in target order
*/
- if ((flags & FLAT_FLAG_GOTPIC) == 0)
- addr = ntohl(addr);
+ if ((flags & FLAT_FLAG_GOTPIC) == 0) {
+ /*
+ * Meh, the same value can have a different
+ * byte order based on a flag..
+ */
+ addr = ntohl((__force __be32)addr);
+ }
addr = calc_reloc(addr, libinfo, id, 0);
if (addr == RELOC_FAILED) {
ret = -ENOEXEC;
@@ -821,14 +845,15 @@ static int load_flat_file(struct linux_binprm *bprm,
goto err;
}
}
+#ifdef CONFIG_BINFMT_FLAT_OLD
} else {
for (i = 0; i < relocs; i++) {
- u32 relval;
+ __be32 relval;
if (get_user(relval, reloc + i))
return -EFAULT;
- relval = ntohl(relval);
- old_reloc(relval);
+ old_reloc(ntohl(relval));
}
+#endif /* CONFIG_BINFMT_FLAT_OLD */
}
flush_icache_range(start_code, end_code);