Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...

5 files changed, 13 insertions, 18 deletions

diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c
index a43d42bf0a86..783b9247161f 100644
--- a/arch/um/kernel/exec.c
+++ b/arch/um/kernel/exec.c
@@ -32,7 +32,7 @@ void flush_thread(void)
 	if (ret) {
 		printk(KERN_ERR "flush_thread - clearing address space failed, "
 		       "err = %d\n", ret);
-		force_sig(SIGKILL, current);
+		force_sig(SIGKILL);
 	}
 	get_safe_registers(current_pt_regs()->regs.gp,
 			   current_pt_regs()->regs.fp);
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index 5f47422401e1..da1e96b1ec3e 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -112,13 +112,12 @@ long arch_ptrace(struct task_struct *child, long request,
 	return ret;
 }
 
-static void send_sigtrap(struct task_struct *tsk, struct uml_pt_regs *regs,
-		  int error_code)
+static void send_sigtrap(struct uml_pt_regs *regs, int error_code)
 {
 	/* Send us the fake SIGTRAP */
 	force_sig_fault(SIGTRAP, TRAP_BRKPT,
 			/* User-mode eip? */
-			UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL, tsk);
+			UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL);
 }
 
 /*
@@ -147,7 +146,7 @@ void syscall_trace_leave(struct pt_regs *regs)
 
 	/* Fake a debug trap */
 	if (ptraced & PT_DTRACE)
-		send_sigtrap(current, &regs->regs, 0);
+		send_sigtrap(&regs->regs, 0);
 
 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 		return;
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 7a1f2a936fd1..29e7f5f9f188 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -119,7 +119,7 @@ void uml_setup_stubs(struct mm_struct *mm)
 	return;
 
 out:
-	force_sigsegv(SIGSEGV, current);
+	force_sigsegv(SIGSEGV);
 }
 
 void arch_exit_mmap(struct mm_struct *mm)
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 8347161c2ae0..45f739bf302f 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -329,7 +329,7 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
 		       "process: %d\n", task_tgid_vnr(current));
 		/* We are under mmap_sem, release it such that current can terminate */
 		up_write(&current->mm->mmap_sem);
-		force_sig(SIGKILL, current);
+		force_sig(SIGKILL);
 		do_signal(&current->thread.regs);
 	}
 }
@@ -487,7 +487,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 
 kill:
 	printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
-	force_sig(SIGKILL, current);
+	force_sig(SIGKILL);
 }
 
 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 0e8b6158f224..58fe36856182 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -163,13 +163,12 @@ static void show_segv_info(struct uml_pt_regs *regs)
 static void bad_segv(struct faultinfo fi, unsigned long ip)
 {
 	current->thread.arch.faultinfo = fi;
-	force_sig_fault(SIGSEGV, SEGV_ACCERR, (void __user *) FAULT_ADDRESS(fi),
-			current);
+	force_sig_fault(SIGSEGV, SEGV_ACCERR, (void __user *) FAULT_ADDRESS(fi));
 }
 
 void fatal_sigsegv(void)
 {
-	force_sigsegv(SIGSEGV, current);
+	force_sigsegv(SIGSEGV);
 	do_signal(&current->thread.regs);
 	/*
 	 * This is to tell gcc that we're not returning - do_signal
@@ -268,13 +267,11 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 	if (err == -EACCES) {
 		current->thread.arch.faultinfo = fi;
-		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address,
-				current);
+		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
 	} else {
 		BUG_ON(err != -EFAULT);
 		current->thread.arch.faultinfo = fi;
-		force_sig_fault(SIGSEGV, si_code, (void __user *) address,
-				current);
+		force_sig_fault(SIGSEGV, si_code, (void __user *) address);
 	}
 
 out:
@@ -304,12 +301,11 @@ void relay_signal(int sig, struct siginfo *si, struct uml_pt_regs *regs)
 	if ((err == 0) && (siginfo_layout(sig, code) == SIL_FAULT)) {
 		struct faultinfo *fi = UPT_FAULTINFO(regs);
 		current->thread.arch.faultinfo = *fi;
-		force_sig_fault(sig, code, (void __user *)FAULT_ADDRESS(*fi),
-				current);
+		force_sig_fault(sig, code, (void __user *)FAULT_ADDRESS(*fi));
 	} else {
 		printk(KERN_ERR "Attempted to relay unknown signal %d (si_code = %d) with errno %d\n",
 		       sig, code, err);
-		force_sig(sig, current);
+		force_sig(sig);
 	}
 }