diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-11 07:42:03 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-11 07:42:03 +0300 |
commit | 398364a35daed7361e76c3666fb9a97792edce09 (patch) | |
tree | 7a63b4df27d2dc75da8549499c79805128183f28 /fs | |
parent | d2b6b4c832f7e3067709e8d4970b7b82b44419ac (diff) | |
parent | ad97f9df0fee4ddc9ef056dda4dcbc6630d9f972 (diff) |
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.binfmt | 18 | ||||
-rw-r--r-- | fs/binfmt_flat.c | 99 |
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); |