ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS

The IBPB control code in x86 removed the usage. Remove the functionality
which was introduced for this.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.559149393@linutronix.de

diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 6c2ffed..de20ede 100644 (file)
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -64,15 +64,12 @@ extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead);
 #define PTRACE_MODE_NOAUDIT    0x04
 #define PTRACE_MODE_FSCREDS    0x08
 #define PTRACE_MODE_REALCREDS  0x10
-#define PTRACE_MODE_SCHED      0x20
-#define PTRACE_MODE_IBPB       0x40
 
 /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */
 #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS)
 #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS)
 #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS)
 #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS)
-#define PTRACE_MODE_SPEC_IBPB (PTRACE_MODE_ATTACH_REALCREDS | PTRACE_MODE_IBPB)
 
 /**
  * ptrace_may_access - check whether the caller is permitted to access
@@ -90,20 +87,6 @@ extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead);
  */
 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
 
-/**
- * ptrace_may_access - check whether the caller is permitted to access
- * a target task.
- * @task: target task
- * @mode: selects type of access and caller credentials
- *
- * Returns true on success, false on denial.
- *
- * Similar to ptrace_may_access(). Only to be called from context switch
- * code. Does not call into audit and the regular LSM hooks due to locking
- * constraints.
- */
-extern bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode);
-
 static inline int ptrace_reparented(struct task_struct *child)
 {
        return !same_thread_group(child->real_parent, child->parent);

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 80b34df..c2cee9d 100644 (file)
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -261,9 +261,6 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
 
 static int ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
 {
-       if (mode & PTRACE_MODE_SCHED)
-               return false;
-
        if (mode & PTRACE_MODE_NOAUDIT)
                return has_ns_capability_noaudit(current, ns, CAP_SYS_PTRACE);
        else
@@ -331,16 +328,9 @@ ok:
             !ptrace_has_cap(mm->user_ns, mode)))
            return -EPERM;
 
-       if (mode & PTRACE_MODE_SCHED)
-               return 0;
        return security_ptrace_access_check(task, mode);
 }
 
-bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode)
-{
-       return __ptrace_may_access(task, mode | PTRACE_MODE_SCHED);
-}
-
 bool ptrace_may_access(struct task_struct *task, unsigned int mode)
 {
        int err;