[REVIEW][PATCH 11/22] signal/openrisc: Use force_sig_fault where appropriate

From: Eric W. Biederman
Date: Fri Apr 20 2018 - 10:46:28 EST


Filling in struct siginfo before calling force_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 force_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 force_sig_info.

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

Cc: Jonas Bonn <jonas@xxxxxxxxxxxx>
Cc: Stefan Kristiansson <stefan.kristiansson@xxxxxxxxxxxxx>
Cc: Stafford Horne <shorne@xxxxxxxxx>
Cc: openrisc@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/openrisc/kernel/traps.c | 33 ++++-----------------------------
arch/openrisc/mm/fault.c | 19 +++++--------------
2 files changed, 9 insertions(+), 43 deletions(-)

diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c
index 1610b1d65a11..fac246e6f37a 100644
--- a/arch/openrisc/kernel/traps.c
+++ b/arch/openrisc/kernel/traps.c
@@ -250,28 +250,16 @@ void __init trap_init(void)

asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
{
- siginfo_t info;
- clear_siginfo(&info);
- info.si_signo = SIGTRAP;
- info.si_code = TRAP_TRACE;
- info.si_addr = (void *)address;
- force_sig_info(SIGTRAP, &info, current);
+ force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)address, current);

regs->pc += 4;
}

asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)
{
- siginfo_t info;
-
if (user_mode(regs)) {
/* Send a SIGBUS */
- clear_siginfo(&info);
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRALN;
- info.si_addr = (void __user *)address;
- force_sig_info(SIGBUS, &info, current);
+ force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address, current);
} else {
printk("KERNEL: Unaligned Access 0x%.8lx\n", address);
show_registers(regs);
@@ -282,16 +270,9 @@ asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address)

asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address)
{
- siginfo_t info;
-
if (user_mode(regs)) {
/* Send a SIGBUS */
- clear_siginfo(&info);
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRERR;
- info.si_addr = (void *)address;
- force_sig_info(SIGBUS, &info, current);
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, current);
} else { /* Kernel mode */
printk("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);
show_registers(regs);
@@ -466,7 +447,6 @@ static inline void simulate_swa(struct pt_regs *regs, unsigned long address,
asmlinkage void do_illegal_instruction(struct pt_regs *regs,
unsigned long address)
{
- siginfo_t info;
unsigned int op;
unsigned int insn = *((unsigned int *)address);

@@ -487,12 +467,7 @@ asmlinkage void do_illegal_instruction(struct pt_regs *regs,

if (user_mode(regs)) {
/* Send a SIGILL */
- clear_siginfo(&info);
- info.si_signo = SIGILL;
- info.si_errno = 0;
- info.si_code = ILL_ILLOPC;
- info.si_addr = (void *)address;
- force_sig_info(SIGBUS, &info, current);
+ force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address, current);
} else { /* Kernel mode */
printk("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",
address);
diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index 68be33e4ae17..9f011d16cc46 100644
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -52,11 +52,10 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct *vma;
- siginfo_t info;
+ int si_code;
int fault;
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;

- clear_siginfo(&info);
tsk = current;

/*
@@ -98,7 +97,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
}

mm = tsk->mm;
- info.si_code = SEGV_MAPERR;
+ si_code = SEGV_MAPERR;

/*
* If we're in an interrupt or have no user
@@ -140,7 +139,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
*/

good_area:
- info.si_code = SEGV_ACCERR;
+ si_code = SEGV_ACCERR;

/* first do some preliminary protection checks */

@@ -214,11 +213,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
/* User mode accesses just cause a SIGSEGV */

if (user_mode(regs)) {
- info.si_signo = SIGSEGV;
- info.si_errno = 0;
- /* info.si_code has been set above */
- info.si_addr = (void *)address;
- force_sig_info(SIGSEGV, &info, tsk);
+ force_sig_fault(SIGSEGV, si_code, (void __user *)address, tsk);
return;
}

@@ -283,11 +278,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRERR;
- info.si_addr = (void *)address;
- force_sig_info(SIGBUS, &info, tsk);
+ force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address, tsk);

/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
--
2.14.1