x86/traps: Introduce fill_trap_info(), simplify DO_ERROR_INFO()

Extract the fill-siginfo code from DO_ERROR_INFO() into the new helper,
fill_trap_info().

It can calculate si_code and si_addr looking at trapnr, so we can remove
these arguments from DO_ERROR_INFO() and simplify the source code. The
generated code is the same, __builtin_constant_p(trapnr) == T.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>

1 files changed, 38 insertions, 15 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index ab8dad719b9e..1cf8a4c409b6 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -136,6 +136,33 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
         return -1;
 }
 
+static void fill_trap_info(struct pt_regs *regs, int signr, int trapnr,
+                           siginfo_t *info)
+{
+        unsigned long siaddr;
+        int sicode;
+
+        switch (trapnr) {
+        case X86_TRAP_DE:
+                sicode = FPE_INTDIV;
+                siaddr = regs->ip;
+                break;
+        case X86_TRAP_UD:
+                sicode = ILL_ILLOPN;
+                siaddr = regs->ip;
+                break;
+        case X86_TRAP_AC:
+                sicode = BUS_ADRALN;
+                siaddr = 0;
+                break;
+        }
+
+        info->si_signo = signr;
+        info->si_errno = 0;
+        info->si_code = sicode;
+        info->si_addr = (void __user *)siaddr;
+}
+
 static void __kprobes
 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
         long error_code, siginfo_t *info)
@@ -191,30 +218,26 @@ dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	\
         do_error_trap(regs, error_code, str, trapnr, signr, NULL);      \
 }
 
-#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr)         \
+#define DO_ERROR_INFO(trapnr, signr, str, name)                         \
 dotraplinkage void do_##name(struct pt_regs *regs, long error_code)     \
 {                                                                       \
         siginfo_t info;                                                 \
                                                                         \
-        info.si_signo = signr;                                          \
-        info.si_errno = 0;                                              \
-        info.si_code = sicode;                                          \
-        info.si_addr = (void __user *)siaddr;                           \
-                                                                        \
+        fill_trap_info(regs, signr, trapnr, &info);                     \
         do_error_trap(regs, error_code, str, trapnr, signr, &info);     \
 }
 
-DO_ERROR_INFO(X86_TRAP_DE,     SIGFPE,  "divide error",                 divide_error,                FPE_INTDIV, regs->ip )
-DO_ERROR     (X86_TRAP_OF,     SIGSEGV, "overflow",                     overflow                                          )
-DO_ERROR     (X86_TRAP_BR,     SIGSEGV, "bounds",                       bounds                                            )
-DO_ERROR_INFO(X86_TRAP_UD,     SIGILL,  "invalid opcode",               invalid_op,                  ILL_ILLOPN, regs->ip )
-DO_ERROR     (X86_TRAP_OLD_MF, SIGFPE,  "coprocessor segment overrun",  coprocessor_segment_overrun                       )
-DO_ERROR     (X86_TRAP_TS,     SIGSEGV, "invalid TSS",                  invalid_TSS                                       )
-DO_ERROR     (X86_TRAP_NP,     SIGBUS,  "segment not present",          segment_not_present                               )
+DO_ERROR_INFO(X86_TRAP_DE,     SIGFPE,  "divide error",                 divide_error)
+DO_ERROR     (X86_TRAP_OF,     SIGSEGV, "overflow",                     overflow)
+DO_ERROR     (X86_TRAP_BR,     SIGSEGV, "bounds",                       bounds)
+DO_ERROR_INFO(X86_TRAP_UD,     SIGILL,  "invalid opcode",               invalid_op)
+DO_ERROR     (X86_TRAP_OLD_MF, SIGFPE,  "coprocessor segment overrun",  coprocessor_segment_overrun)
+DO_ERROR     (X86_TRAP_TS,     SIGSEGV, "invalid TSS",                  invalid_TSS)
+DO_ERROR     (X86_TRAP_NP,     SIGBUS,  "segment not present",          segment_not_present)
 #ifdef CONFIG_X86_32
-DO_ERROR     (X86_TRAP_SS,     SIGBUS,  "stack segment",                stack_segment                                     )
+DO_ERROR     (X86_TRAP_SS,     SIGBUS,  "stack segment",                stack_segment)
 #endif
-DO_ERROR_INFO(X86_TRAP_AC,     SIGBUS,  "alignment check",              alignment_check,             BUS_ADRALN, 0        )
+DO_ERROR_INFO(X86_TRAP_AC,     SIGBUS,  "alignment check",              alignment_check)
 
 #ifdef CONFIG_X86_64
 /* Runs on IST stack */