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
  ...

4 files changed, 13 insertions, 12 deletions

diff --git a/arch/nds32/kernel/fpu.c b/arch/nds32/kernel/fpu.c
index cf0b8760f261..62bdafbc53f4 100644
--- a/arch/nds32/kernel/fpu.c
+++ b/arch/nds32/kernel/fpu.c
@@ -243,7 +243,7 @@ inline void handle_fpu_exception(struct pt_regs *regs)
 	}
 
 	force_sig_fault(si_signo, si_code,
-			(void __user *)instruction_pointer(regs), current);
+			(void __user *)instruction_pointer(regs));
 done:
 	own_fpu();
 }
diff --git a/arch/nds32/kernel/signal.c b/arch/nds32/kernel/signal.c
index 5f7660aa2d68..fe61513982b4 100644
--- a/arch/nds32/kernel/signal.c
+++ b/arch/nds32/kernel/signal.c
@@ -163,7 +163,7 @@ asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 	return regs->uregs[0];
 
 badframe:
-	force_sig(SIGSEGV, current);
+	force_sig(SIGSEGV);
 	return 0;
 }
 
diff --git a/arch/nds32/kernel/traps.c b/arch/nds32/kernel/traps.c
index 5aa7c17da27a..f4d386b52622 100644
--- a/arch/nds32/kernel/traps.c
+++ b/arch/nds32/kernel/traps.c
@@ -205,7 +205,7 @@ int bad_syscall(int n, struct pt_regs *regs)
 	}
 
 	force_sig_fault(SIGILL, ILL_ILLTRP,
-			(void __user *)instruction_pointer(regs) - 4, current);
+			(void __user *)instruction_pointer(regs) - 4);
 	die_if_kernel("Oops - bad syscall", regs, n);
 	return regs->uregs[0];
 }
@@ -255,14 +255,15 @@ void __init early_trap_init(void)
 	cpu_cache_wbinval_page(base, true);
 }
 
-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
-		  int error_code, int si_code)
+static void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
 {
+	struct task_struct *tsk = current;
+
 	tsk->thread.trap_no = ENTRY_DEBUG_RELATED;
 	tsk->thread.error_code = error_code;
 
 	force_sig_fault(SIGTRAP, si_code,
-			(void __user *)instruction_pointer(regs), tsk);
+			(void __user *)instruction_pointer(regs));
 }
 
 void do_debug_trap(unsigned long entry, unsigned long addr,
@@ -274,7 +275,7 @@ void do_debug_trap(unsigned long entry, unsigned long addr,
 
 	if (user_mode(regs)) {
 		/* trap_signal */
-		send_sigtrap(current, regs, 0, TRAP_BRKPT);
+		send_sigtrap(regs, 0, TRAP_BRKPT);
 	} else {
 		/* kernel_trap */
 		if (!fixup_exception(regs))
@@ -288,7 +289,7 @@ void unhandled_interruption(struct pt_regs *regs)
 	show_regs(regs);
 	if (!user_mode(regs))
 		do_exit(SIGKILL);
-	force_sig(SIGKILL, current);
+	force_sig(SIGKILL);
 }
 
 void unhandled_exceptions(unsigned long entry, unsigned long addr,
@@ -299,7 +300,7 @@ void unhandled_exceptions(unsigned long entry, unsigned long addr,
 	show_regs(regs);
 	if (!user_mode(regs))
 		do_exit(SIGKILL);
-	force_sig(SIGKILL, current);
+	force_sig(SIGKILL);
 }
 
 extern int do_page_fault(unsigned long entry, unsigned long addr,
@@ -326,7 +327,7 @@ void do_revinsn(struct pt_regs *regs)
 	show_regs(regs);
 	if (!user_mode(regs))
 		do_exit(SIGILL);
-	force_sig(SIGILL, current);
+	force_sig(SIGILL);
 }
 
 #ifdef CONFIG_ALIGNMENT_TRAP
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c
index 68d5f2a27f38..064ae5d2159d 100644
--- a/arch/nds32/mm/fault.c
+++ b/arch/nds32/mm/fault.c
@@ -271,7 +271,7 @@ bad_area_nosemaphore:
 		tsk->thread.address = addr;
 		tsk->thread.error_code = error_code;
 		tsk->thread.trap_no = entry;
-		force_sig_fault(SIGSEGV, si_code, (void __user *)addr, tsk);
+		force_sig_fault(SIGSEGV, si_code, (void __user *)addr);
 		return;
 	}
 
@@ -340,7 +340,7 @@ do_sigbus:
 	tsk->thread.address = addr;
 	tsk->thread.error_code = error_code;
 	tsk->thread.trap_no = entry;
-	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr, tsk);
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)addr);
 
 	return;