Final si_trapno bits

As a part of a fix for the ABI of the newly added SIGTRAP TRAP_PERF a
si_trapno was reduced to an ordinary extention of the _sigfault case
of struct siginfo.

When Linus saw the complete set of changes come in as a fix he requested
that the set of changes be trimmed down to just what was necessary to
fix the SIGTRAP TRAP_PERF ABI.

I had intended to get the rest of the changes into the merge window for
v5.14 but I dropped the ball.

I have made the changes to stop using __ARCH_SI_TRAPNO be per
architecture so they are easier to review.  In doing so I found one
place on alpha where I used send_sig_fault instead of
send_sig_fault_trapno(... si_trapno = 0).  That would not have changed
the userspace behavior but it did make the kernel code less clear.

My rule in these patches is everywhere that siginfo layout calls
for SIL_FAULT_TRAPNO the code uses either force_sig_fault_trapno
or send_sig_fault_trapno.

And of course I have rebased and compile tested Marco's compile time
assert patches.

v1: https://lkml.kernel.org/r/m1zgxfs7zq.fsf_-_@fess.ebiederm.org
v2: https://lkml.kernel.org/r/m14kfjh8et.fsf_-_@fess.ebiederm.org
v3: https://lkml.kernel.org/r/m1tuni8ano.fsf_-_@fess.ebiederm.org
v4: https://lkml.kernel.org/r/m1a6ot5e2h.fsf_-_@fess.ebiederm.org
Link: https://lkml.kernel.org/r/87a6mnzbx2.fsf_-_@disp2133

Eric W. Biederman (5):
      signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP
      signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK
      signal: Remove the generic __ARCH_SI_TRAPNO support
      signal: Verify the alignment and size of siginfo_t
      signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency

Marco Elver (3):
      sparc64: Add compile-time asserts for siginfo_t offsets
      arm: Add compile-time asserts for siginfo_t offsets
      arm64: Add compile-time asserts for siginfo_t offsets

 arch/alpha/include/uapi/asm/siginfo.h |  2 --
 arch/alpha/kernel/osf_sys.c           |  2 +-
 arch/alpha/kernel/signal.c            |  4 +--
 arch/alpha/kernel/traps.c             | 26 +++++++--------
 arch/alpha/mm/fault.c                 |  4 +--
 arch/arm/kernel/signal.c              | 39 ++++++++++++++++++++++
 arch/arm64/kernel/signal.c            | 39 ++++++++++++++++++++++
 arch/arm64/kernel/signal32.c          | 39 ++++++++++++++++++++++
 arch/mips/include/uapi/asm/siginfo.h  |  2 --
 arch/sparc/include/uapi/asm/siginfo.h |  3 --
 arch/sparc/kernel/process_64.c        |  2 +-
 arch/sparc/kernel/signal32.c          | 37 +++++++++++++++++++++
 arch/sparc/kernel/signal_64.c         | 36 ++++++++++++++++++++
 arch/sparc/kernel/sys_sparc_32.c      |  2 +-
 arch/sparc/kernel/sys_sparc_64.c      |  2 +-
 arch/sparc/kernel/traps_32.c          | 22 ++++++-------
 arch/sparc/kernel/traps_64.c          | 44 +++++++++++--------------
 arch/sparc/kernel/unaligned_32.c      |  2 +-
 arch/sparc/mm/fault_32.c              |  2 +-
 arch/sparc/mm/fault_64.c              |  2 +-
 arch/x86/kernel/signal_compat.c       |  6 ++++
 fs/signalfd.c                         |  4 +--
 include/linux/sched/signal.h          | 11 ++-----
 include/linux/signal.h                |  2 +-
 include/uapi/asm-generic/siginfo.h    |  5 +++
 kernel/signal.c                       | 62 +++++++++++++++++++++++++----------
 26 files changed, 305 insertions(+), 96 deletions(-)

5 files changed, 18 insertions, 20 deletions

diff --git a/arch/alpha/include/uapi/asm/siginfo.h b/arch/alpha/include/uapi/asm/siginfo.h
index 6e1a2af2f962..e08eae88182b 100644
--- a/arch/alpha/include/uapi/asm/siginfo.h
+++ b/arch/alpha/include/uapi/asm/siginfo.h
@@ -2,8 +2,6 @@
 #ifndef _ALPHA_SIGINFO_H
 #define _ALPHA_SIGINFO_H
 
-#define __ARCH_SI_TRAPNO
-
 #include <asm-generic/siginfo.h>
 
 #endif
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index d5367a1c6300..bbdb1a9a5fd8 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -876,7 +876,7 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer,
 			if (fex & IEEE_TRAP_ENABLE_DZE) si_code = FPE_FLTDIV;
 			if (fex & IEEE_TRAP_ENABLE_INV) si_code = FPE_FLTINV;
 
-			send_sig_fault(SIGFPE, si_code,
+			send_sig_fault_trapno(SIGFPE, si_code,
 				       (void __user *)NULL,  /* FIXME */
 				       0, current);
  		}
diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index 948b89789da8..bc077babafab 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -219,7 +219,7 @@ do_sigreturn(struct sigcontext __user *sc)
 
 	/* Send SIGTRAP if we're single-stepping: */
 	if (ptrace_cancel_bpt (current)) {
-		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc,
 			       current);
 	}
 	return;
@@ -247,7 +247,7 @@ do_rt_sigreturn(struct rt_sigframe __user *frame)
 
 	/* Send SIGTRAP if we're single-stepping: */
 	if (ptrace_cancel_bpt (current)) {
-		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *) regs->pc,
 			       current);
 	}
 	return;
diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c
index 921d4b6e4d95..e9e3de18793b 100644
--- a/arch/alpha/kernel/traps.c
+++ b/arch/alpha/kernel/traps.c
@@ -227,7 +227,7 @@ do_entArith(unsigned long summary, unsigned long write_mask,
 	}
 	die_if_kernel("Arithmetic fault", regs, 0, NULL);
 
-	send_sig_fault(SIGFPE, si_code, (void __user *) regs->pc, 0, current);
+	send_sig_fault_trapno(SIGFPE, si_code, (void __user *) regs->pc, 0, current);
 }
 
 asmlinkage void
@@ -268,13 +268,13 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 			regs->pc -= 4;	/* make pc point to former bpt */
 		}
 
-		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc, 0,
+		send_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc,
 			       current);
 		return;
 
 	      case 1: /* bugcheck */
-		send_sig_fault(SIGTRAP, TRAP_UNK, (void __user *) regs->pc, 0,
-			       current);
+		send_sig_fault_trapno(SIGTRAP, TRAP_UNK,
+				      (void __user *) regs->pc, 0, current);
 		return;
 		
 	      case 2: /* gentrap */
@@ -335,8 +335,8 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 			break;
 		}
 
-		send_sig_fault(signo, code, (void __user *) regs->pc, regs->r16,
-			       current);
+		send_sig_fault_trapno(signo, code, (void __user *) regs->pc,
+				      regs->r16, current);
 		return;
 
 	      case 4: /* opDEC */
@@ -360,9 +360,9 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 			if (si_code == 0)
 				return;
 			if (si_code > 0) {
-				send_sig_fault(SIGFPE, si_code,
-					       (void __user *) regs->pc, 0,
-					       current);
+				send_sig_fault_trapno(SIGFPE, si_code,
+						      (void __user *) regs->pc,
+						      0, current);
 				return;
 			}
 		}
@@ -387,7 +387,7 @@ do_entIF(unsigned long type, struct pt_regs *regs)
 		      ;
 	}
 
-	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc, 0, current);
+	send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc, current);
 }
 
 /* There is an ifdef in the PALcode in MILO that enables a 
@@ -402,7 +402,7 @@ do_entDbg(struct pt_regs *regs)
 {
 	die_if_kernel("Instruction fault", regs, 0, NULL);
 
-	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc, 0);
+	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)regs->pc);
 }
 
 
@@ -964,12 +964,12 @@ give_sigsegv:
 			si_code = SEGV_MAPERR;
 		mmap_read_unlock(mm);
 	}
-	send_sig_fault(SIGSEGV, si_code, va, 0, current);
+	send_sig_fault(SIGSEGV, si_code, va, current);
 	return;
 
 give_sigbus:
 	regs->pc -= 4;
-	send_sig_fault(SIGBUS, BUS_ADRALN, va, 0, current);
+	send_sig_fault(SIGBUS, BUS_ADRALN, va, current);
 	return;
 }
 
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 09172f017efc..eee5102c3d88 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -219,13 +219,13 @@ retry:
 	mmap_read_unlock(mm);
 	/* Send a sigbus, regardless of whether we were in kernel
 	   or user mode.  */
-	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *) address, 0);
+	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *) address);
 	if (!user_mode(regs))
 		goto no_context;
 	return;
 
  do_sigsegv:
-	force_sig_fault(SIGSEGV, si_code, (void __user *) address, 0);
+	force_sig_fault(SIGSEGV, si_code, (void __user *) address);
 	return;
 
 #ifdef CONFIG_ALPHA_LARGE_VMALLOC