[PATCH 5/6] signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK
From: Eric W. Biederman
Date: Thu Jul 15 2021 - 14:13:00 EST
While reviewing the signal handlers on alpha it became clear that
si_trapno is only set to a non-zero value when sending SIGFPE and when
sending SITGRAP with si_code TRAP_UNK.
Add send_sig_fault_trapno and send SIGTRAP TRAP_UNK, and SIGFPE with it.
Remove the define of __ARCH_SI_TRAPNO and remove the always zero
si_trapno parameter from send_sig_fault and force_sig_fault.
v1: https://lkml.kernel.org/r/m1eeers7q7.fsf_-_@xxxxxxxxxxxxxxxxx
v2: https://lkml.kernel.org/r/20210505141101.11519-7-ebiederm@xxxxxxxxxxxx
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
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 ++--
include/linux/sched/signal.h | 2 ++
kernel/signal.c | 21 +++++++++++++++++++++
7 files changed, 41 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 @@ do_entUnaUser(void __user * va, unsigned long opcode,
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 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
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
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 99a9ab2b169a..6657184cef07 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -330,6 +330,8 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data);
int force_sig_ptrace_errno_trap(int errno, void __user *addr);
int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno);
+int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
+ struct task_struct *t);
extern int send_sig_info(int, struct kernel_siginfo *, struct task_struct *);
extern void force_sigsegv(int sig);
diff --git a/kernel/signal.c b/kernel/signal.c
index 87a374225277..ae06a424aa72 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1824,6 +1824,23 @@ int force_sig_fault_trapno(int sig, int code, void __user *addr, int trapno)
return force_sig_info(&info);
}
+/* For the rare architectures that include trap information using
+ * si_trapno.
+ */
+int send_sig_fault_trapno(int sig, int code, void __user *addr, int trapno,
+ struct task_struct *t)
+{
+ struct kernel_siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = sig;
+ info.si_errno = 0;
+ info.si_code = code;
+ info.si_addr = addr;
+ info.si_trapno = trapno;
+ return send_sig_info(info.si_signo, &info, t);
+}
+
int kill_pgrp(struct pid *pid, int sig, int priv)
{
int ret;
@@ -3262,6 +3279,10 @@ enum siginfo_layout siginfo_layout(unsigned sig, int si_code)
else if (IS_ENABLED(CONFIG_SPARC) &&
(sig == SIGILL) && (si_code == ILL_ILLTRP))
layout = SIL_FAULT_TRAPNO;
+ else if (IS_ENABLED(CONFIG_ALPHA) &&
+ ((sig == SIGFPE) ||
+ ((sig == SIGTRAP) && (si_code == TRAP_UNK))))
+ layout = SIL_FAULT_TRAPNO;
#ifdef __ARCH_SI_TRAPNO
else if (layout == SIL_FAULT)
layout = SIL_FAULT_TRAPNO;
--
2.20.1