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tracehook: exec 

This moves all the ptrace hooks related to exec into tracehook.h inlines.

This also lifts the calls for tracing out of the binfmt load_binary hooks
into search_binary_handler() after it calls into the binfmt module.  This
change has no effect, since all the binfmt modules' load_binary functions
did the call at the end on success, and now search_binary_handler() does
it immediately after return if successful.  We consolidate the repeated
code, and binfmt modules no longer need to import ptrace_notify().

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Roland McGrath 2008-07-25 19:45:44 -07:00 committed by Linus Torvalds
parent 88ac2921a7
commit 6341c393fc
8 changed files with 50 additions and 38 deletions
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6
arch/x86/ia32/ia32_aout.c
View File

@ -441,12 +441,6 @@ beyond_if:
regs->r8 = regs->r9 = regs->r10 = regs->r11 =
regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
set_fs(USER_DS);
if (unlikely(current->ptrace & PT_PTRACED)) {
if (current->ptrace & PT_TRACE_EXEC)
ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
else
send_sig(SIGTRAP, current, 0);
}
return 0;
}

6
fs/binfmt_aout.c
View File

@ -444,12 +444,6 @@ beyond_if:
regs->gp = ex.a_gpvalue;
#endif
start_thread(regs, ex.a_entry, current->mm->start_stack);
if (unlikely(current->ptrace & PT_PTRACED)) {
if (current->ptrace & PT_TRACE_EXEC)
ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
else
send_sig(SIGTRAP, current, 0);
}
return 0;
}

6
fs/binfmt_elf.c
View File

@ -1003,12 +1003,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
#endif
start_thread(regs, elf_entry, bprm->p);
if (unlikely(current->ptrace & PT_PTRACED)) {
if (current->ptrace & PT_TRACE_EXEC)
ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
else
send_sig(SIGTRAP, current, 0);
}
retval = 0;
out:
kfree(loc);

7
fs/binfmt_elf_fdpic.c
View File

@ -433,13 +433,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
start_thread(regs, entryaddr, current->mm->start_stack);
if (unlikely(current->ptrace & PT_PTRACED)) {
if (current->ptrace & PT_TRACE_EXEC)
ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
else
send_sig(SIGTRAP, current, 0);
}
retval = 0;
error:

3
fs/binfmt_flat.c
View File

@ -920,9 +920,6 @@ static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
start_thread(regs, start_addr, current->mm->start_stack);
if (current->ptrace & PT_PTRACED)
send_sig(SIGTRAP, current, 0);
return 0;
}

2
fs/binfmt_som.c
View File

@ -274,8 +274,6 @@ load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
map_hpux_gateway_page(current,current->mm);
start_thread_som(regs, som_entry, bprm->p);
if (current->ptrace & PT_PTRACED)
send_sig(SIGTRAP, current, 0);
return 0;
/* error cleanup */

12
fs/exec.c
View File

@ -42,13 +42,13 @@
#include <linux/module.h>
#include <linux/namei.h>
#include <linux/proc_fs.h>
#include <linux/ptrace.h>
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/tsacct_kern.h>
#include <linux/cn_proc.h>
#include <linux/audit.h>
#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@ -1071,13 +1071,8 @@ EXPORT_SYMBOL(prepare_binprm);
static int unsafe_exec(struct task_struct *p)
{
int unsafe = 0;
if (p->ptrace & PT_PTRACED) {
if (p->ptrace & PT_PTRACE_CAP)
unsafe |= LSM_UNSAFE_PTRACE_CAP;
else
unsafe |= LSM_UNSAFE_PTRACE;
}
int unsafe = tracehook_unsafe_exec(p);
if (atomic_read(&p->fs->count) > 1 ||
atomic_read(&p->files->count) > 1 ||
atomic_read(&p->sighand->count) > 1)
@ -1214,6 +1209,7 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
read_unlock(&binfmt_lock);
retval = fn(bprm, regs);
if (retval >= 0) {
tracehook_report_exec(fmt, bprm, regs);
put_binfmt(fmt);
allow_write_access(bprm->file);
if (bprm->file)

46
include/linux/tracehook.h
View File

@ -48,5 +48,51 @@
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/security.h>
struct linux_binprm;
/**
* tracehook_unsafe_exec - check for exec declared unsafe due to tracing
* @task: current task doing exec
*
* Return %LSM_UNSAFE_* bits applied to an exec because of tracing.
*
* Called with task_lock() held on @task.
*/
static inline int tracehook_unsafe_exec(struct task_struct *task)
{
int unsafe = 0;
int ptrace = task_ptrace(task);
if (ptrace & PT_PTRACED) {
if (ptrace & PT_PTRACE_CAP)
unsafe |= LSM_UNSAFE_PTRACE_CAP;
else
unsafe |= LSM_UNSAFE_PTRACE;
}
return unsafe;
}
/**
* tracehook_report_exec - a successful exec was completed
* @fmt: &struct linux_binfmt that performed the exec
* @bprm: &struct linux_binprm containing exec details
* @regs: user-mode register state
*
* An exec just completed, we are shortly going to return to user mode.
* The freshly initialized register state can be seen and changed in @regs.
* The name, file and other pointers in @bprm are still on hand to be
* inspected, but will be freed as soon as this returns.
*
* Called with no locks, but with some kernel resources held live
* and a reference on @fmt->module.
*/
static inline void tracehook_report_exec(struct linux_binfmt *fmt,
struct linux_binprm *bprm,
struct pt_regs *regs)
{
if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) &&
unlikely(task_ptrace(current) & PT_PTRACED))
send_sig(SIGTRAP, current, 0);
}
#endif /* <linux/tracehook.h> */