[S390] cleanup trap handling

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>

1 files changed, 59 insertions, 109 deletions

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index a9807dd86276..dc6cc1b0ae66 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -43,7 +43,7 @@
 #include <asm/debug.h>
 #include "entry.h"
 
-void (*pgm_check_table[128])(struct pt_regs *, long, unsigned long);
+void (*pgm_check_table[128])(struct pt_regs *regs);
 
 int show_unhandled_signals;
 
@@ -234,7 +234,7 @@ void show_regs(struct pt_regs *regs)
 
 static DEFINE_SPINLOCK(die_lock);
 
-void die(const char * str, struct pt_regs * regs, long err)
+void die(struct pt_regs *regs, const char *str)
 {
         static int die_counter;
 
@@ -243,7 +243,7 @@ void die(const char * str, struct pt_regs * regs, long err)
         console_verbose();
         spin_lock_irq(&die_lock);
         bust_spinlocks(1);
-        printk("%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
+        printk("%s: %04x [#%d] ", str, regs->int_code & 0xffff, ++die_counter);
 #ifdef CONFIG_PREEMPT
         printk("PREEMPT ");
 #endif
@@ -254,7 +254,7 @@ void die(const char * str, struct pt_regs * regs, long err)
         printk("DEBUG_PAGEALLOC");
 #endif
         printk("\n");
-        notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
+        notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
         show_regs(regs);
         bust_spinlocks(0);
         add_taint(TAINT_DIE);
@@ -267,8 +267,7 @@ void die(const char * str, struct pt_regs * regs, long err)
         do_exit(SIGSEGV);
 }
 
-static void inline report_user_fault(struct pt_regs *regs, long int_code,
-                                     int signr)
+static inline void report_user_fault(struct pt_regs *regs, int signr)
 {
         if ((task_pid_nr(current) > 1) && !show_unhandled_signals)
                 return;
@@ -276,7 +275,7 @@ static void inline 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("User process fault: interruption code 0x%X ", regs->int_code);
         print_vma_addr("in ", regs->psw.addr & PSW_ADDR_INSN);
         printk("\n");
         show_regs(regs);
@@ -287,19 +286,28 @@ int is_valid_bugaddr(unsigned long addr)
         return 1;
 }
 
-static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
-                                     struct pt_regs *regs, siginfo_t *info)
+static inline void __user *get_psw_address(struct pt_regs *regs)
 {
-        if (notify_die(DIE_TRAP, str, regs, pgm_int_code,
-                       pgm_int_code, signr) == NOTIFY_STOP)
+        return (void __user *)
+                ((regs->psw.addr - (regs->int_code >> 16)) & PSW_ADDR_INSN);
+}
+
+static void __kprobes do_trap(struct pt_regs *regs,
+                              int si_signo, int si_code, char *str)
+{
+        siginfo_t info;
+
+        if (notify_die(DIE_TRAP, str, regs, 0,
+                       regs->int_code, si_signo) == NOTIFY_STOP)
                 return;
 
         if (regs->psw.mask & PSW_MASK_PSTATE) {
-                struct task_struct *tsk = current;
-
-                tsk->thread.trap_no = pgm_int_code & 0xffff;
-                force_sig_info(signr, info, tsk);
-                report_user_fault(regs, pgm_int_code, signr);
+                info.si_signo = si_signo;
+                info.si_errno = 0;
+                info.si_code = si_code;
+                info.si_addr = get_psw_address(regs);
+                force_sig_info(si_signo, &info, current);
+                report_user_fault(regs, si_signo);
         } else {
                 const struct exception_table_entry *fixup;
                 fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
@@ -311,18 +319,11 @@ static inline void __kprobes do_trap(long pgm_int_code, int signr, char *str,
                         btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
                         if (btt == BUG_TRAP_TYPE_WARN)
                                 return;
-                        die(str, regs, pgm_int_code);
+                        die(regs, str);
                 }
         }
 }
 
-static inline void __user *get_psw_address(struct pt_regs *regs,
-                                           long pgm_int_code)
-{
-        return (void __user *)
-                ((regs->psw.addr - (pgm_int_code >> 16)) & PSW_ADDR_INSN);
-}
-
 void __kprobes do_per_trap(struct pt_regs *regs)
 {
         siginfo_t info;
@@ -339,26 +340,19 @@ void __kprobes do_per_trap(struct pt_regs *regs)
         force_sig_info(SIGTRAP, &info, current);
 }
 
-static void default_trap_handler(struct pt_regs *regs, long pgm_int_code,
-                                 unsigned long trans_exc_code)
+static void default_trap_handler(struct pt_regs *regs)
 {
         if (regs->psw.mask & PSW_MASK_PSTATE) {
-                report_user_fault(regs, pgm_int_code, SIGSEGV);
+                report_user_fault(regs, SIGSEGV);
                 do_exit(SIGSEGV);
         } else
-                die("Unknown program exception", regs, pgm_int_code);
+                die(regs, "Unknown program exception");
 }
 
 #define DO_ERROR_INFO(name, signr, sicode, str) \
-static void name(struct pt_regs *regs, long pgm_int_code, \
-                 unsigned long trans_exc_code) \
+static void name(struct pt_regs *regs) \
 { \
-        siginfo_t info; \
-        info.si_signo = signr; \
-        info.si_errno = 0; \
-        info.si_code = sicode; \
-        info.si_addr = get_psw_address(regs, pgm_int_code); \
-        do_trap(pgm_int_code, signr, str, regs, &info);     \
+        do_trap(regs, signr, sicode, str); \
 }
 
 DO_ERROR_INFO(addressing_exception, SIGILL, ILL_ILLADR,
@@ -388,42 +382,34 @@ DO_ERROR_INFO(special_op_exception, SIGILL, ILL_ILLOPN,
 DO_ERROR_INFO(translation_exception, SIGILL, ILL_ILLOPN,
               "translation exception")
 
-static inline void do_fp_trap(struct pt_regs *regs, void __user *location,
-                              int fpc, long pgm_int_code)
+static inline void do_fp_trap(struct pt_regs *regs, int fpc)
 {
-        siginfo_t si;
-
-        si.si_signo = SIGFPE;
-        si.si_errno = 0;
-        si.si_addr = location;
-        si.si_code = 0;
+        int si_code = 0;
         /* FPC[2] is Data Exception Code */
         if ((fpc & 0x00000300) == 0) {
                 /* bits 6 and 7 of DXC are 0 iff IEEE exception */
                 if (fpc & 0x8000) /* invalid fp operation */
-                        si.si_code = FPE_FLTINV;
+                        si_code = FPE_FLTINV;
                 else if (fpc & 0x4000) /* div by 0 */
-                        si.si_code = FPE_FLTDIV;
+                        si_code = FPE_FLTDIV;
                 else if (fpc & 0x2000) /* overflow */
-                        si.si_code = FPE_FLTOVF;
+                        si_code = FPE_FLTOVF;
                 else if (fpc & 0x1000) /* underflow */
-                        si.si_code = FPE_FLTUND;
+                        si_code = FPE_FLTUND;
                 else if (fpc & 0x0800) /* inexact */
-                        si.si_code = FPE_FLTRES;
+                        si_code = FPE_FLTRES;
         }
-        do_trap(pgm_int_code, SIGFPE,
-                "floating point exception", regs, &si);
+        do_trap(regs, SIGFPE, si_code, "floating point exception");
 }
 
-static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
-                                 unsigned long trans_exc_code)
+static void __kprobes illegal_op(struct pt_regs *regs)
 {
         siginfo_t info;
         __u8 opcode[6];
         __u16 __user *location;
         int signal = 0;
 
-        location = get_psw_address(regs, pgm_int_code);
+        location = get_psw_address(regs);
 
         if (regs->psw.mask & PSW_MASK_PSTATE) {
                 if (get_user(*((__u16 *) opcode), (__u16 __user *) location))
@@ -467,44 +453,31 @@ static void __kprobes illegal_op(struct pt_regs *regs, long pgm_int_code,
                  * If we get an illegal op in kernel mode, send it through the
                  * kprobes notifier. If kprobes doesn't pick it up, SIGILL
                  */
-                if (notify_die(DIE_BPT, "bpt", regs, pgm_int_code,
+                if (notify_die(DIE_BPT, "bpt", regs, 0,
                                3, SIGTRAP) != NOTIFY_STOP)
                         signal = SIGILL;
         }
 
 #ifdef CONFIG_MATHEMU
         if (signal == SIGFPE)
-                do_fp_trap(regs, location,
-                           current->thread.fp_regs.fpc, pgm_int_code);
-        else if (signal == SIGSEGV) {
-                info.si_signo = signal;
-                info.si_errno = 0;
-                info.si_code = SEGV_MAPERR;
-                info.si_addr = (void __user *) location;
-                do_trap(pgm_int_code, signal,
-                        "user address fault", regs, &info);
-        } else
+                do_fp_trap(regs, current->thread.fp_regs.fpc);
+        else if (signal == SIGSEGV)
+                do_trap(regs, signal, SEGV_MAPERR, "user address fault");
+        else
 #endif
-        if (signal) {
-                info.si_signo = signal;
-                info.si_errno = 0;
-                info.si_code = ILL_ILLOPC;
-                info.si_addr = (void __user *) location;
-                do_trap(pgm_int_code, signal,
-                        "illegal operation", regs, &info);
-        }
+        if (signal)
+                do_trap(regs, signal, ILL_ILLOPC, "illegal operation");
 }
 
 
 #ifdef CONFIG_MATHEMU
-void specification_exception(struct pt_regs *regs, long pgm_int_code,
-                             unsigned long trans_exc_code)
+void specification_exception(struct pt_regs *regs)
 {
         __u8 opcode[6];
         __u16 __user *location = NULL;
         int signal = 0;
 
-        location = (__u16 __user *) get_psw_address(regs, pgm_int_code);
+        location = (__u16 __user *) get_psw_address(regs);
 
         if (regs->psw.mask & PSW_MASK_PSTATE) {
                 get_user(*((__u16 *) opcode), location);
@@ -539,30 +512,21 @@ void specification_exception(struct pt_regs *regs, long pgm_int_code,
                 signal = SIGILL;
 
         if (signal == SIGFPE)
-                do_fp_trap(regs, location,
-                           current->thread.fp_regs.fpc, pgm_int_code);
-        else if (signal) {
-                siginfo_t info;
-                info.si_signo = signal;
-                info.si_errno = 0;
-                info.si_code = ILL_ILLOPN;
-                info.si_addr = location;
-                do_trap(pgm_int_code, signal,
-                        "specification exception", regs, &info);
-        }
+                do_fp_trap(regs, current->thread.fp_regs.fpc);
+        else if (signal)
+                do_trap(regs, signal, ILL_ILLOPN, "specification exception");
 }
 #else
 DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
               "specification exception");
 #endif
 
-static void data_exception(struct pt_regs *regs, long pgm_int_code,
-                           unsigned long trans_exc_code)
+static void data_exception(struct pt_regs *regs)
 {
         __u16 __user *location;
         int signal = 0;
 
-        location = get_psw_address(regs, pgm_int_code);
+        location = get_psw_address(regs);
 
         if (MACHINE_HAS_IEEE)
                 asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
@@ -627,32 +591,18 @@ static void data_exception(struct pt_regs *regs, long pgm_int_code,
         else
                 signal = SIGILL;
         if (signal == SIGFPE)
-                do_fp_trap(regs, location,
-                           current->thread.fp_regs.fpc, pgm_int_code);
-        else if (signal) {
-                siginfo_t info;
-                info.si_signo = signal;
-                info.si_errno = 0;
-                info.si_code = ILL_ILLOPN;
-                info.si_addr = location;
-                do_trap(pgm_int_code, signal, "data exception", regs, &info);
-        }
+                do_fp_trap(regs, current->thread.fp_regs.fpc);
+        else if (signal)
+                do_trap(regs, signal, ILL_ILLOPN, "data exception");
 }
 
-static void space_switch_exception(struct pt_regs *regs, long pgm_int_code,
-                                   unsigned long trans_exc_code)
+static void space_switch_exception(struct pt_regs *regs)
 {
-        siginfo_t info;
-
         /* Set user psw back to home space mode. */
         if (regs->psw.mask & PSW_MASK_PSTATE)
                 regs->psw.mask |= PSW_ASC_HOME;
         /* Send SIGILL. */
-        info.si_signo = SIGILL;
-        info.si_errno = 0;
-        info.si_code = ILL_PRVOPC;
-        info.si_addr = get_psw_address(regs, pgm_int_code);
-        do_trap(pgm_int_code, SIGILL, "space switch event", regs, &info);
+        do_trap(regs, SIGILL, ILL_PRVOPC, "space switch event");
 }
 
 void __kprobes kernel_stack_overflow(struct pt_regs * regs)