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
  ...

2 files changed, 6 insertions, 8 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 58e4f1f00bbc..794f364cb882 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -760,8 +760,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
 			set_signal_archinfo(address, error_code);
 
 			/* XXX: hwpoison faults will set the wrong code. */
-			force_sig_fault(signal, si_code, (void __user *)address,
-					tsk);
+			force_sig_fault(signal, si_code, (void __user *)address);
 		}
 
 		/*
@@ -922,7 +921,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
 		if (si_code == SEGV_PKUERR)
 			force_sig_pkuerr((void __user *)address, pkey);
 
-		force_sig_fault(SIGSEGV, si_code, (void __user *)address, tsk);
+		force_sig_fault(SIGSEGV, si_code, (void __user *)address);
 
 		return;
 	}
@@ -1019,8 +1018,6 @@ static void
 do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
 	  vm_fault_t fault)
 {
-	struct task_struct *tsk = current;
-
 	/* Kernel mode? Handle exceptions or die: */
 	if (!(error_code & X86_PF_USER)) {
 		no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
@@ -1035,6 +1032,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
 
 #ifdef CONFIG_MEMORY_FAILURE
 	if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
+		struct task_struct *tsk = current;
 		unsigned lsb = 0;
 
 		pr_err(
@@ -1044,11 +1042,11 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
 			lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
 		if (fault & VM_FAULT_HWPOISON)
 			lsb = PAGE_SHIFT;
-		force_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, tsk);
+		force_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb);
 		return;
 	}
 #endif
-	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, tsk);
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);
 }
 
 static noinline void
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 0d1c47cbbdd6..895fb7a9294d 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -912,7 +912,7 @@ void mpx_notify_unmap(struct mm_struct *mm, unsigned long start,
 
 	ret = mpx_unmap_tables(mm, start, end);
 	if (ret)
-		force_sig(SIGSEGV, current);
+		force_sig(SIGSEGV);
 }
 
 /* MPX cannot handle addresses above 47 bits yet. */