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[S390] cleanup trap handling

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Move the program interruption code and the translation exception identifier
to the pt_regs structure as 'int_code' and 'int_parm_long' and make the
first level interrupt handler in entry[64].S store the two values. That
makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct
and to reduce the number of arguments to a lot of functions. Finally
un-inline do_trap. Overall this saves 5812 bytes in the .text section of
the 64 bit kernel.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2011-12-27 11:27:18 +01:00
parent 679e2ea733
commit aa33c8cbba
12 changed files with 158 additions and 210 deletions
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101
arch/s390/mm/fault.c
View File

@ -125,8 +125,7 @@ static inline int user_space_fault(unsigned long trans_exc_code)
return trans_exc_code != 3;
}
static inline void report_user_fault(struct pt_regs *regs, long int_code,
int signr, unsigned long address)
static inline void report_user_fault(struct pt_regs *regs, long signr)
{
if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
return;
@ -134,10 +133,12 @@ static inline void report_user_fault(struct pt_regs *regs, long int_code,
return;
if (!printk_ratelimit())
return;
printk("User process fault: interruption code 0x%lX ", int_code);
printk(KERN_ALERT "User process fault: interruption code 0x%X ",
regs->int_code);
print_vma_addr(KERN_CONT "in ", regs->psw.addr & PSW_ADDR_INSN);
printk("\n");
printk("failing address: %lX\n", address);
printk(KERN_CONT "\n");
printk(KERN_ALERT "failing address: %lX\n",
regs->int_parm_long & __FAIL_ADDR_MASK);
show_regs(regs);
}
@ -145,24 +146,18 @@ static inline void report_user_fault(struct pt_regs *regs, long int_code,
* Send SIGSEGV to task. This is an external routine
* to keep the stack usage of do_page_fault small.
*/
static noinline void do_sigsegv(struct pt_regs *regs, long int_code,
int si_code, unsigned long trans_exc_code)
static noinline void do_sigsegv(struct pt_regs *regs, int si_code)
{
struct siginfo si;
unsigned long address;
address = trans_exc_code & __FAIL_ADDR_MASK;
current->thread.prot_addr = address;
current->thread.trap_no = int_code;
report_user_fault(regs, int_code, SIGSEGV, address);
report_user_fault(regs, SIGSEGV);
si.si_signo = SIGSEGV;
si.si_code = si_code;
si.si_addr = (void __user *) address;
si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK);
force_sig_info(SIGSEGV, &si, current);
}
static noinline void do_no_context(struct pt_regs *regs, long int_code,
unsigned long trans_exc_code)
static noinline void do_no_context(struct pt_regs *regs)
{
const struct exception_table_entry *fixup;
unsigned long address;
@ -178,55 +173,48 @@ static noinline void do_no_context(struct pt_regs *regs, long int_code,
* Oops. The kernel tried to access some bad page. We'll have to
* terminate things with extreme prejudice.
*/
address = trans_exc_code & __FAIL_ADDR_MASK;
if (!user_space_fault(trans_exc_code))
address = regs->int_parm_long & __FAIL_ADDR_MASK;
if (!user_space_fault(regs->int_parm_long))
printk(KERN_ALERT "Unable to handle kernel pointer dereference"
" at virtual kernel address %p\n", (void *)address);
else
printk(KERN_ALERT "Unable to handle kernel paging request"
" at virtual user address %p\n", (void *)address);
die("Oops", regs, int_code);
die(regs, "Oops");
do_exit(SIGKILL);
}
static noinline void do_low_address(struct pt_regs *regs, long int_code,
unsigned long trans_exc_code)
static noinline void do_low_address(struct pt_regs *regs)
{
/* Low-address protection hit in kernel mode means
NULL pointer write access in kernel mode. */
if (regs->psw.mask & PSW_MASK_PSTATE) {
/* Low-address protection hit in user mode 'cannot happen'. */
die ("Low-address protection", regs, int_code);
die (regs, "Low-address protection");
do_exit(SIGKILL);
}
do_no_context(regs, int_code, trans_exc_code);
do_no_context(regs);
}
static noinline void do_sigbus(struct pt_regs *regs, long int_code,
unsigned long trans_exc_code)
static noinline void do_sigbus(struct pt_regs *regs)
{
struct task_struct *tsk = current;
unsigned long address;
struct siginfo si;
/*
* Send a sigbus, regardless of whether we were in kernel
* or user mode.
*/
address = trans_exc_code & __FAIL_ADDR_MASK;
tsk->thread.prot_addr = address;
tsk->thread.trap_no = int_code;
si.si_signo = SIGBUS;
si.si_errno = 0;
si.si_code = BUS_ADRERR;
si.si_addr = (void __user *) address;
si.si_addr = (void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK);
force_sig_info(SIGBUS, &si, tsk);
}
static noinline void do_fault_error(struct pt_regs *regs, long int_code,
unsigned long trans_exc_code, int fault)
static noinline void do_fault_error(struct pt_regs *regs, int fault)
{
int si_code;
@ -238,24 +226,24 @@ static noinline void do_fault_error(struct pt_regs *regs, long int_code,
/* User mode accesses just cause a SIGSEGV */
si_code = (fault == VM_FAULT_BADMAP) ?
SEGV_MAPERR : SEGV_ACCERR;
do_sigsegv(regs, int_code, si_code, trans_exc_code);
do_sigsegv(regs, si_code);
return;
}
case VM_FAULT_BADCONTEXT:
do_no_context(regs, int_code, trans_exc_code);
do_no_context(regs);
break;
default: /* fault & VM_FAULT_ERROR */
if (fault & VM_FAULT_OOM) {
if (!(regs->psw.mask & PSW_MASK_PSTATE))
do_no_context(regs, int_code, trans_exc_code);
do_no_context(regs);
else
pagefault_out_of_memory();
} else if (fault & VM_FAULT_SIGBUS) {
/* Kernel mode? Handle exceptions or die */
if (!(regs->psw.mask & PSW_MASK_PSTATE))
do_no_context(regs, int_code, trans_exc_code);
do_no_context(regs);
else
do_sigbus(regs, int_code, trans_exc_code);
do_sigbus(regs);
} else
BUG();
break;
@ -273,12 +261,12 @@ static noinline void do_fault_error(struct pt_regs *regs, long int_code,
* 11 Page translation -> Not present (nullification)
* 3b Region third trans. -> Not present (nullification)
*/
static inline int do_exception(struct pt_regs *regs, int access,
unsigned long trans_exc_code)
static inline int do_exception(struct pt_regs *regs, int access)
{
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct *vma;
unsigned long trans_exc_code;
unsigned long address;
unsigned int flags;
int fault;
@ -288,6 +276,7 @@ static inline int do_exception(struct pt_regs *regs, int access,
tsk = current;
mm = tsk->mm;
trans_exc_code = regs->int_parm_long;
/*
* Verify that the fault happened in user space, that
@ -387,45 +376,46 @@ out:
return fault;
}
void __kprobes do_protection_exception(struct pt_regs *regs, long pgm_int_code,
unsigned long trans_exc_code)
void __kprobes do_protection_exception(struct pt_regs *regs)
{
unsigned long trans_exc_code;
int fault;
trans_exc_code = regs->int_parm_long;
/* Protection exception is suppressing, decrement psw address. */
regs->psw.addr = __rewind_psw(regs->psw, pgm_int_code >> 16);
regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
/*
* Check for low-address protection. This needs to be treated
* as a special case because the translation exception code
* field is not guaranteed to contain valid data in this case.
*/
if (unlikely(!(trans_exc_code & 4))) {
do_low_address(regs, pgm_int_code, trans_exc_code);
do_low_address(regs);
return;
}
fault = do_exception(regs, VM_WRITE, trans_exc_code);
fault = do_exception(regs, VM_WRITE);
if (unlikely(fault))
do_fault_error(regs, 4, trans_exc_code, fault);
do_fault_error(regs, fault);
}
void __kprobes do_dat_exception(struct pt_regs *regs, long pgm_int_code,
unsigned long trans_exc_code)
void __kprobes do_dat_exception(struct pt_regs *regs)
{
int access, fault;
access = VM_READ | VM_EXEC | VM_WRITE;
fault = do_exception(regs, access, trans_exc_code);
fault = do_exception(regs, access);
if (unlikely(fault))
do_fault_error(regs, pgm_int_code & 255, trans_exc_code, fault);
do_fault_error(regs, fault);
}
#ifdef CONFIG_64BIT
void __kprobes do_asce_exception(struct pt_regs *regs, long pgm_int_code,
unsigned long trans_exc_code)
void __kprobes do_asce_exception(struct pt_regs *regs)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long trans_exc_code;
trans_exc_code = regs->int_parm_long;
if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm))
goto no_context;
@ -440,12 +430,12 @@ void __kprobes do_asce_exception(struct pt_regs *regs, long pgm_int_code,
/* User mode accesses just cause a SIGSEGV */
if (regs->psw.mask & PSW_MASK_PSTATE) {
do_sigsegv(regs, pgm_int_code, SEGV_MAPERR, trans_exc_code);
do_sigsegv(regs, SEGV_MAPERR);
return;
}
no_context:
do_no_context(regs, pgm_int_code, trans_exc_code);
do_no_context(regs);
}
#endif
@ -459,14 +449,15 @@ int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write)
regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT;
regs.psw.addr = (unsigned long) __builtin_return_address(0);
regs.psw.addr |= PSW_ADDR_AMODE;
uaddr &= PAGE_MASK;
regs.int_code = pgm_int_code;
regs.int_parm_long = (uaddr & PAGE_MASK) | 2;
access = write ? VM_WRITE : VM_READ;
fault = do_exception(&regs, access, uaddr | 2);
fault = do_exception(&regs, access);
if (unlikely(fault)) {
if (fault & VM_FAULT_OOM)
return -EFAULT;
else if (fault & VM_FAULT_SIGBUS)
do_sigbus(&regs, pgm_int_code, uaddr);
do_sigbus(&regs);
}
return fault ? -EFAULT : 0;
}