[REVIEW][PATCH 17/22] signal/sparc: Use send_sig_fault where appropriate

From: Eric W. Biederman
Date: Fri Apr 20 2018 - 10:48:32 EST


Filling in struct siginfo before calling send_sig_info a tedious and
error prone process, where once in a great while the wrong fields
are filled out, and siginfo has been inconsistently cleared.

Simplify this process by using the helper send_sig_fault. Which
takes as a parameters all of the information it needs, ensures
all of the fiddly bits of filling in struct siginfo are done properly
and then calls send_sig_info.

In short about a 5 line reduction in code for every time send_sig_info
is called, which makes the calling function clearer.

Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: sparclinux@xxxxxxxxxxxxxxx
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/sparc/kernel/traps_32.c | 93 ++++++++--------------------------------
arch/sparc/kernel/unaligned_32.c | 12 ++----
2 files changed, 20 insertions(+), 85 deletions(-)

diff --git a/arch/sparc/kernel/traps_32.c b/arch/sparc/kernel/traps_32.c
index 03e522274b8b..06f43cf9695f 100644
--- a/arch/sparc/kernel/traps_32.c
+++ b/arch/sparc/kernel/traps_32.c
@@ -116,8 +116,6 @@ void do_hw_interrupt(struct pt_regs *regs, unsigned long type)
void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
if(psr & PSR_PS)
die_if_kernel("Kernel illegal instruction", regs);
#ifdef TRAP_DEBUG
@@ -125,29 +123,15 @@ void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned lon
regs->pc, *(unsigned long *)regs->pc);
#endif

- clear_siginfo(&info);
- info.si_signo = SIGILL;
- info.si_errno = 0;
- info.si_code = ILL_ILLOPC;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- send_sig_info(SIGILL, &info, current);
+ send_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc, 0, current);
}

void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
if(psr & PSR_PS)
die_if_kernel("Penguin instruction from Penguin mode??!?!", regs);
- clear_siginfo(&info);
- info.si_signo = SIGILL;
- info.si_errno = 0;
- info.si_code = ILL_PRVOPC;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- send_sig_info(SIGILL, &info, current);
+ send_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)pc, 0, current);
}

/* XXX User may want to be allowed to do this. XXX */
@@ -155,8 +139,6 @@ void do_priv_instruction(struct pt_regs *regs, unsigned long pc, unsigned long n
void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
if(regs->psr & PSR_PS) {
printk("KERNEL MNA at pc %08lx npc %08lx called by %08lx\n", pc, npc,
regs->u_regs[UREG_RETPC]);
@@ -168,13 +150,9 @@ void do_memaccess_unaligned(struct pt_regs *regs, unsigned long pc, unsigned lon
instruction_dump ((unsigned long *) regs->pc);
printk ("do_MNA!\n");
#endif
- clear_siginfo(&info);
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRALN;
- info.si_addr = /* FIXME: Should dig out mna address */ (void *)0;
- info.si_trapno = 0;
- send_sig_info(SIGBUS, &info, current);
+ send_sig_fault(SIGBUS, BUS_ADRALN,
+ /* FIXME: Should dig out mna address */ (void *)0,
+ 0, current);
}

static unsigned long init_fsr = 0x0UL;
@@ -230,9 +208,9 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
static int calls;
- siginfo_t info;
unsigned long fsr;
int ret = 0;
+ int code;
#ifndef CONFIG_SMP
struct task_struct *fpt = last_task_used_math;
#else
@@ -307,25 +285,20 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
}

fsr = fpt->thread.fsr;
- clear_siginfo(&info);
- info.si_signo = SIGFPE;
- info.si_errno = 0;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- info.si_code = FPE_FLTUNK;
+ code = FPE_FLTUNK;
if ((fsr & 0x1c000) == (1 << 14)) {
if (fsr & 0x10)
- info.si_code = FPE_FLTINV;
+ code = FPE_FLTINV;
else if (fsr & 0x08)
- info.si_code = FPE_FLTOVF;
+ code = FPE_FLTOVF;
else if (fsr & 0x04)
- info.si_code = FPE_FLTUND;
+ code = FPE_FLTUND;
else if (fsr & 0x02)
- info.si_code = FPE_FLTDIV;
+ code = FPE_FLTDIV;
else if (fsr & 0x01)
- info.si_code = FPE_FLTRES;
+ code = FPE_FLTRES;
}
- send_sig_info(SIGFPE, &info, fpt);
+ send_sig_fault(SIGFPE, code, (void __user *)pc, 0, fpt);
#ifndef CONFIG_SMP
last_task_used_math = NULL;
#endif
@@ -337,17 +310,9 @@ void do_fpe_trap(struct pt_regs *regs, unsigned long pc, unsigned long npc,
void handle_tag_overflow(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
if(psr & PSR_PS)
die_if_kernel("Penguin overflow trap from kernel mode", regs);
- clear_siginfo(&info);
- info.si_signo = SIGEMT;
- info.si_errno = 0;
- info.si_code = EMT_TAGOVF;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- send_sig_info(SIGEMT, &info, current);
+ send_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)pc, 0, current);
}

void handle_watchpoint(struct pt_regs *regs, unsigned long pc, unsigned long npc,
@@ -383,47 +348,23 @@ void handle_reg_access(struct pt_regs *regs, unsigned long pc, unsigned long npc
void handle_cp_disabled(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
- clear_siginfo(&info);
- info.si_signo = SIGILL;
- info.si_errno = 0;
- info.si_code = ILL_COPROC;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- send_sig_info(SIGILL, &info, current);
+ send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
}

void handle_cp_exception(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
#ifdef TRAP_DEBUG
printk("Co-Processor Exception at PC %08lx NPC %08lx PSR %08lx\n",
pc, npc, psr);
#endif
- clear_siginfo(&info);
- info.si_signo = SIGILL;
- info.si_errno = 0;
- info.si_code = ILL_COPROC;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- send_sig_info(SIGILL, &info, current);
+ send_sig_fault(SIGILL, ILL_COPROC, (void __user *)pc, 0, current);
}

void handle_hw_divzero(struct pt_regs *regs, unsigned long pc, unsigned long npc,
unsigned long psr)
{
- siginfo_t info;
-
- clear_siginfo(&info);
- info.si_signo = SIGFPE;
- info.si_errno = 0;
- info.si_code = FPE_INTDIV;
- info.si_addr = (void __user *)pc;
- info.si_trapno = 0;
- send_sig_info(SIGFPE, &info, current);
+ send_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)pc, 0, current);
}

#ifdef CONFIG_DEBUG_BUGVERBOSE
diff --git a/arch/sparc/kernel/unaligned_32.c b/arch/sparc/kernel/unaligned_32.c
index 0e4cf7217413..64ac8c0c1429 100644
--- a/arch/sparc/kernel/unaligned_32.c
+++ b/arch/sparc/kernel/unaligned_32.c
@@ -311,15 +311,9 @@ static inline int ok_for_user(struct pt_regs *regs, unsigned int insn,

static void user_mna_trap_fault(struct pt_regs *regs, unsigned int insn)
{
- siginfo_t info;
-
- clear_siginfo(&info);
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRALN;
- info.si_addr = (void __user *)safe_compute_effective_address(regs, insn);
- info.si_trapno = 0;
- send_sig_info(SIGBUS, &info, current);
+ send_sig_fault(SIGBUS, BUS_ADRALN,
+ (void __user *)safe_compute_effective_address(regs, insn),
+ 0, current);
}

asmlinkage void user_unaligned_trap(struct pt_regs *regs, unsigned int insn)
--
2.14.1