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Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c128
1 files changed, 94 insertions, 34 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 422370293cfd..879ff9c7ffd0 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -35,6 +35,10 @@
#include <linux/utsname.h>
#include <linux/coredump.h>
#include <linux/sched.h>
+#include <linux/sched/coredump.h>
+#include <linux/sched/task_stack.h>
+#include <linux/sched/cputime.h>
+#include <linux/cred.h>
#include <linux/dax.h>
#include <linux/uaccess.h>
#include <asm/param.h>
@@ -91,12 +95,18 @@ static struct linux_binfmt elf_format = {
#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
-static int set_brk(unsigned long start, unsigned long end)
+static int set_brk(unsigned long start, unsigned long end, int prot)
{
start = ELF_PAGEALIGN(start);
end = ELF_PAGEALIGN(end);
if (end > start) {
- int error = vm_brk(start, end - start);
+ /*
+ * Map the last of the bss segment.
+ * If the header is requesting these pages to be
+ * executable, honour that (ppc32 needs this).
+ */
+ int error = vm_brk_flags(start, end - start,
+ prot & PROT_EXEC ? VM_EXEC : 0);
if (error)
return error;
}
@@ -153,8 +163,6 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
unsigned long p = bprm->p;
int argc = bprm->argc;
int envc = bprm->envc;
- elf_addr_t __user *argv;
- elf_addr_t __user *envp;
elf_addr_t __user *sp;
elf_addr_t __user *u_platform;
elf_addr_t __user *u_base_platform;
@@ -294,38 +302,38 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
/* Now, let's put argc (and argv, envp if appropriate) on the stack */
if (__put_user(argc, sp++))
return -EFAULT;
- argv = sp;
- envp = argv + argc + 1;
- /* Populate argv and envp */
+ /* Populate list of argv pointers back to argv strings. */
p = current->mm->arg_end = current->mm->arg_start;
while (argc-- > 0) {
size_t len;
- if (__put_user((elf_addr_t)p, argv++))
+ if (__put_user((elf_addr_t)p, sp++))
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- if (__put_user(0, argv))
+ if (__put_user(0, sp++))
return -EFAULT;
- current->mm->arg_end = current->mm->env_start = p;
+ current->mm->arg_end = p;
+
+ /* Populate list of envp pointers back to envp strings. */
+ current->mm->env_end = current->mm->env_start = p;
while (envc-- > 0) {
size_t len;
- if (__put_user((elf_addr_t)p, envp++))
+ if (__put_user((elf_addr_t)p, sp++))
return -EFAULT;
len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
if (!len || len > MAX_ARG_STRLEN)
return -EINVAL;
p += len;
}
- if (__put_user(0, envp))
+ if (__put_user(0, sp++))
return -EFAULT;
current->mm->env_end = p;
/* Put the elf_info on the stack in the right place. */
- sp = (elf_addr_t __user *)envp + 1;
if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
return -EFAULT;
return 0;
@@ -524,6 +532,7 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
unsigned long load_addr = 0;
int load_addr_set = 0;
unsigned long last_bss = 0, elf_bss = 0;
+ int bss_prot = 0;
unsigned long error = ~0UL;
unsigned long total_size;
int i;
@@ -606,8 +615,10 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
* elf_bss and last_bss is the bss section.
*/
k = load_addr + eppnt->p_vaddr + eppnt->p_memsz;
- if (k > last_bss)
+ if (k > last_bss) {
last_bss = k;
+ bss_prot = elf_prot;
+ }
}
}
@@ -623,13 +634,14 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
/*
* Next, align both the file and mem bss up to the page size,
* since this is where elf_bss was just zeroed up to, and where
- * last_bss will end after the vm_brk() below.
+ * last_bss will end after the vm_brk_flags() below.
*/
elf_bss = ELF_PAGEALIGN(elf_bss);
last_bss = ELF_PAGEALIGN(last_bss);
/* Finally, if there is still more bss to allocate, do it. */
if (last_bss > elf_bss) {
- error = vm_brk(elf_bss, last_bss - elf_bss);
+ error = vm_brk_flags(elf_bss, last_bss - elf_bss,
+ bss_prot & PROT_EXEC ? VM_EXEC : 0);
if (error)
goto out;
}
@@ -674,6 +686,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
unsigned long error;
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
unsigned long elf_bss, elf_brk;
+ int bss_prot = 0;
int retval, i;
unsigned long elf_entry;
unsigned long interp_load_addr = 0;
@@ -882,7 +895,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
before this one. Map anonymous pages, if needed,
and clear the area. */
retval = set_brk(elf_bss + load_bias,
- elf_brk + load_bias);
+ elf_brk + load_bias,
+ bss_prot);
if (retval)
goto out_free_dentry;
nbyte = ELF_PAGEOFFSET(elf_bss);
@@ -911,17 +925,60 @@ static int load_elf_binary(struct linux_binprm *bprm)
elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
vaddr = elf_ppnt->p_vaddr;
+ /*
+ * If we are loading ET_EXEC or we have already performed
+ * the ET_DYN load_addr calculations, proceed normally.
+ */
if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
elf_flags |= MAP_FIXED;
} else if (loc->elf_ex.e_type == ET_DYN) {
- /* Try and get dynamic programs out of the way of the
- * default mmap base, as well as whatever program they
- * might try to exec. This is because the brk will
- * follow the loader, and is not movable. */
- load_bias = ELF_ET_DYN_BASE - vaddr;
- if (current->flags & PF_RANDOMIZE)
- load_bias += arch_mmap_rnd();
- load_bias = ELF_PAGESTART(load_bias);
+ /*
+ * This logic is run once for the first LOAD Program
+ * Header for ET_DYN binaries to calculate the
+ * randomization (load_bias) for all the LOAD
+ * Program Headers, and to calculate the entire
+ * size of the ELF mapping (total_size). (Note that
+ * load_addr_set is set to true later once the
+ * initial mapping is performed.)
+ *
+ * There are effectively two types of ET_DYN
+ * binaries: programs (i.e. PIE: ET_DYN with INTERP)
+ * and loaders (ET_DYN without INTERP, since they
+ * _are_ the ELF interpreter). The loaders must
+ * be loaded away from programs since the program
+ * may otherwise collide with the loader (especially
+ * for ET_EXEC which does not have a randomized
+ * position). For example to handle invocations of
+ * "./ld.so someprog" to test out a new version of
+ * the loader, the subsequent program that the
+ * loader loads must avoid the loader itself, so
+ * they cannot share the same load range. Sufficient
+ * room for the brk must be allocated with the
+ * loader as well, since brk must be available with
+ * the loader.
+ *
+ * Therefore, programs are loaded offset from
+ * ELF_ET_DYN_BASE and loaders are loaded into the
+ * independently randomized mmap region (0 load_bias
+ * without MAP_FIXED).
+ */
+ if (elf_interpreter) {
+ load_bias = ELF_ET_DYN_BASE;
+ if (current->flags & PF_RANDOMIZE)
+ load_bias += arch_mmap_rnd();
+ elf_flags |= MAP_FIXED;
+ } else
+ load_bias = 0;
+
+ /*
+ * Since load_bias is used for all subsequent loading
+ * calculations, we must lower it by the first vaddr
+ * so that the remaining calculations based on the
+ * ELF vaddrs will be correctly offset. The result
+ * is then page aligned.
+ */
+ load_bias = ELF_PAGESTART(load_bias - vaddr);
+
total_size = total_mapping_size(elf_phdata,
loc->elf_ex.e_phnum);
if (!total_size) {
@@ -976,8 +1033,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
if (end_data < k)
end_data = k;
k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
- if (k > elf_brk)
+ if (k > elf_brk) {
+ bss_prot = elf_prot;
elf_brk = k;
+ }
}
loc->elf_ex.e_entry += load_bias;
@@ -993,7 +1052,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
* mapping in the interpreter, to make sure it doesn't wind
* up getting placed where the bss needs to go.
*/
- retval = set_brk(elf_bss, elf_brk);
+ retval = set_brk(elf_bss, elf_brk, bss_prot);
if (retval)
goto out_free_dentry;
if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
@@ -1428,17 +1487,18 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
* group-wide total, not its individual thread total.
*/
thread_group_cputime(p, &cputime);
- cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
- cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
+ prstatus->pr_utime = ns_to_timeval(cputime.utime);
+ prstatus->pr_stime = ns_to_timeval(cputime.stime);
} else {
- cputime_t utime, stime;
+ u64 utime, stime;
task_cputime(p, &utime, &stime);
- cputime_to_timeval(utime, &prstatus->pr_utime);
- cputime_to_timeval(stime, &prstatus->pr_stime);
+ prstatus->pr_utime = ns_to_timeval(utime);
+ prstatus->pr_stime = ns_to_timeval(stime);
}
- cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
- cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
+
+ prstatus->pr_cutime = ns_to_timeval(p->signal->cutime);
+ prstatus->pr_cstime = ns_to_timeval(p->signal->cstime);
}
static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
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