linux-kernel - [PATCH 5/5] kgdbts: unify/generalize gdb breakpoint adjustment

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1302760895-13459-6-git-send-email-vapier@gentoo.org>
Date:	Thu, 14 Apr 2011 02:01:35 -0400
From:	Mike Frysinger <vapier@...too.org>
To:	Roland McGrath <roland@...hat.com>,
	Oleg Nesterov <oleg@...hat.com>, linux-kernel@...r.kernel.org,
	kgdb-bugreport@...ts.sourceforge.net,
	Jason Wessel <jason.wessel@...driver.com>
Cc:	x86@...nel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>, linux-sh@...r.kernel.org,
	Paul Mundt <lethal@...ux-sh.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH 5/5] kgdbts: unify/generalize gdb breakpoint adjustment

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 <vapier@...too.org>
---
 arch/blackfin/include/asm/kgdb.h |    1 +
 arch/sh/include/asm/kgdb.h       |    1 +
 arch/x86/include/asm/kgdb.h      |    1 +
 drivers/misc/kgdbts.c            |   29 +++++++++++------------------
 4 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/arch/blackfin/include/asm/kgdb.h b/arch/blackfin/include/asm/kgdb.h
index 3ac0c72..aaf8845 100644
--- 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
index 4235e22..f361395 100644
--- 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
index 396f5b5..77e95f5 100644
--- 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
index 59c118c..d475ce0 100644
--- 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;
 }
 
-- 
1.7.5.rc1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/