kgdbts: unify/generalize gdb breakpoint adjustment

vapier · torvalds · commit 63ab25ebbc50 · 2011-05-26T17:12:36.000-07:00
The Blackfin arch, like the x86 arch, needs to adjust the PC manually
after a breakpoint is hit as normally this is handled by the remote gdb.
However, rather than starting another arch ifdef mess, create a common
GDB_ADJUSTS_BREAK_OFFSET define for any arch to opt-in via their kgdb.h.

Signed-off-by: Mike Frysinger &lt;vapier@gentoo.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Acked-by: Paul Mundt &lt;lethal@linux-sh.org&gt;
Acked-by: Dongdong Deng &lt;dongdong.deng@windriver.com&gt;
Cc: Sergei Shtylyov &lt;sshtylyov@mvista.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/arch/blackfin/include/asm/kgdb.h b/arch/blackfin/include/asm/kgdb.h
@@ -108,6 +108,7 @@ static inline void arch_kgdb_breakpoint(void)
 #else
 # define CACHE_FLUSH_IS_SAFE	1
 #endif
+#define GDB_ADJUSTS_BREAK_OFFSET
 #define HW_INST_WATCHPOINT_NUM	6
 #define HW_WATCHPOINT_NUM	8
 #define TYPE_INST_WATCHPOINT	0
diff --git a/arch/sh/include/asm/kgdb.h b/arch/sh/include/asm/kgdb.h
@@ -34,5 +34,6 @@ static inline void arch_kgdb_breakpoint(void)
 
 #define CACHE_FLUSH_IS_SAFE	1
 #define BREAK_INSTR_SIZE	2
+#define GDB_ADJUSTS_BREAK_OFFSET
 
 #endif /* __ASM_SH_KGDB_H */
diff --git a/arch/x86/include/asm/kgdb.h b/arch/x86/include/asm/kgdb.h
@@ -77,6 +77,7 @@ static inline void arch_kgdb_breakpoint(void)
 }
 #define BREAK_INSTR_SIZE	1
 #define CACHE_FLUSH_IS_SAFE	1
+#define GDB_ADJUSTS_BREAK_OFFSET
 
 extern int kgdb_ll_trap(int cmd, const char *str,
 			struct pt_regs *regs, long err, int trap, int sig);
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
@@ -285,33 +285,26 @@ static void hw_break_val_write(void)
 static int check_and_rewind_pc(char *put_str, char *arg)
 {
 	unsigned long addr = lookup_addr(arg);
+	unsigned long ip;
 	int offset = 0;
 
 	kgdb_hex2mem(&put_str[1], (char *)kgdbts_gdb_regs,
 		 NUMREGBYTES);
 	gdb_regs_to_pt_regs(kgdbts_gdb_regs, &kgdbts_regs);
-	v2printk("Stopped at IP: %lx\n", instruction_pointer(&kgdbts_regs));
-#ifdef CONFIG_X86
-	/* On x86 a breakpoint stop requires it to be decremented */
-	if (addr + 1 == kgdbts_regs.ip)
-		offset = -1;
-#elif defined(CONFIG_SUPERH)
-	/* On SUPERH a breakpoint stop requires it to be decremented */
-	if (addr + 2 == kgdbts_regs.pc)
-		offset = -2;
+	ip = instruction_pointer(&kgdbts_regs);
+	v2printk("Stopped at IP: %lx\n", ip);
+#ifdef GDB_ADJUSTS_BREAK_OFFSET
+	/* On some arches, a breakpoint stop requires it to be decremented */
+	if (addr + BREAK_INSTR_SIZE == ip)
+		offset = -BREAK_INSTR_SIZE;
 #endif
-	if (strcmp(arg, "silent") &&
-		instruction_pointer(&kgdbts_regs) + offset != addr) {
+	if (strcmp(arg, "silent") && ip + offset != addr) {
 		eprintk("kgdbts: BP mismatch %lx expected %lx\n",
-			   instruction_pointer(&kgdbts_regs) + offset, addr);
+			   ip + offset, addr);
 		return 1;
 	}
-#ifdef CONFIG_X86
-	/* On x86 adjust the instruction pointer if needed */
-	kgdbts_regs.ip += offset;
-#elif defined(CONFIG_SUPERH)
-	kgdbts_regs.pc += offset;
-#endif
+	/* Readjust the instruction pointer if needed */
+	instruction_pointer_set(&kgdbts_regs, ip + offset);
 	return 0;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -77,6 +77,7 @@ static inline void arch_kgdb_breakpoint(void)`
`77`	`77`	`}`
`78`	`78`	`#define BREAK_INSTR_SIZE 1`
`79`	`79`	`#define CACHE_FLUSH_IS_SAFE 1`
	`80`	`+#define GDB_ADJUSTS_BREAK_OFFSET`
`80`	`81`
`81`	`82`	`extern int kgdb_ll_trap(int cmd, const char *str,`
`82`	`83`	`struct pt_regs *regs, long err, int trap, int sig);`