[POWERPC] ptrace shouldn't touch FP exec mode

One of the gratuitous difference between 32 and 64-bit ptrace is whether you can whack the MSR:FE0 and FE1 bits from ptrace. This patch forbids it unconditionally. In addition, the 64-bit kernels used to return the exception mode in the MSR on reads, but 32-bit kernels didn't. This patch makes it return those bits on both. Finally, since ptrace-ppc32.h and ptrace-ppc64.h are mostly empty now, and since the previous patch made ptrace32.c no longer need the MSR_DEBUGCHANGE definition, we just remove those 2 files and move back the remaining bits to ptrace.c (they were short lived heh ?). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] ptrace shouldn't touch FP exec mode
One of the gratuitous difference between 32 and 64-bit ptrace is whether you can whack the MSR:FE0 and FE1 bits from ptrace. This patch forbids it unconditionally. In addition, the 64-bit kernels used to return the exception mode in the MSR on reads, but 32-bit kernels didn't. This patch makes it return those bits on both. Finally, since ptrace-ppc32.h and ptrace-ppc64.h are mostly empty now, and since the previous patch made ptrace32.c no longer need the MSR_DEBUGCHANGE definition, we just remove those 2 files and move back the remaining bits to ptrace.c (they were short lived heh ?). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Benjamin Herrenschmidt · Paul Mackerras
1 parent 912000e73e
Showing 4 changed files with 39 additions and 94 deletions Side-by-side Diff
arch/powerpc/kernel/ptrace-ppc32.h
arch/powerpc/kernel/ptrace-ppc64.h
arch/powerpc/kernel/ptrace.c
arch/powerpc/kernel/ptrace32.c
-/*
- *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
- *    Extracted from ptrace.c and ptrace32.c
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License.  See the file README.legal in the main directory of
- * this archive for more details.
- */
-
-#ifndef _POWERPC_PTRACE_PPC32_H
-#define _POWERPC_PTRACE_PPC32_H
-
-/*
- * Set of msr bits that gdb can change on behalf of a process.
- */
-#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-#define MSR_DEBUGCHANGE	0
-#else
-#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)
-#endif
-
-/*
- * Max register writeable via put_reg
- */
-#define PT_MAX_PUT_REG	PT_MQ
-
-/*
- * Munging of MSR on return from get_regs
- *
- * Nothing to do on ppc32
- */
-#define PT_MUNGE_MSR(msr, task)	(msr)
-
-
-#endif /* _POWERPC_PTRACE_PPC32_H */
-/*
- *    Copyright (c) 2002 Stephen Rothwell, IBM Coproration
- *    Extracted from ptrace.c and ptrace32.c
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License.  See the file README.legal in the main directory of
- * this archive for more details.
- */
-
-#ifndef _POWERPC_PTRACE_PPC64_H
-#define _POWERPC_PTRACE_PPC64_H
-
-/*
- * Set of msr bits that gdb can change on behalf of a process.
- */
-#define MSR_DEBUGCHANGE	(MSR_FE0 | MSR_SE | MSR_BE | MSR_FE1)
-
-/*
- * Max register writeable via put_reg
- */
-#define PT_MAX_PUT_REG	PT_CCR
-
-/*
- * Munging of MSR on return from get_regs
- *
- * Put the correct FP bits in, they might be wrong as a result
- * of our lazy FP restore.
- */
-
-#define PT_MUNGE_MSR(msr, task)	({ (msr) | (task)->thread.fpexc_mode; })
-
-static inline int ptrace_set_debugreg(struct task_struct *task,
-				      unsigned long addr, unsigned long data)
-{
-	/* We only support one DABR and no IABRS at the moment */
-	if (addr > 0)
-		return -EINVAL;
-
-	/* The bottom 3 bits are flags */
-	if ((data & ~0x7UL) >= TASK_SIZE)
-		return -EIO;
-
-	/* Ensure translation is on */
-	if (data && !(data & DABR_TRANSLATION))
-		return -EIO;
-
-	task->thread.dabr = data;
-	return 0;
-}
-
-#endif /* _POWERPC_PTRACE_PPC64_H */
@@ -35,16 +35,28 @@
 #include <asm/pgtable.h>
 #include <asm/system.h>
  
-#ifdef CONFIG_PPC64
-#include "ptrace-ppc64.h"
+/*
+ * does not yet catch signals sent when the child dies.
+ * in exit.c or in signal.c.
+ */
+
+/*
+ * Set of msr bits that gdb can change on behalf of a process.
+ */
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+#define MSR_DEBUGCHANGE	0
 #else
-#include "ptrace-ppc32.h"
+#define MSR_DEBUGCHANGE	(MSR_SE | MSR_BE)
 #endif
  
 /*
- * does not yet catch signals sent when the child dies.
- * in exit.c or in signal.c.
+ * Max register writeable via put_reg
  */
+#ifdef CONFIG_PPC32
+#define PT_MAX_PUT_REG	PT_MQ
+#else
+#define PT_MAX_PUT_REG	PT_CCR
+#endif
  
 /*
  * Get contents of register REGNO in task TASK.
@@ -58,7 +70,7 @@
  
 	if (regno == PT_MSR) {
 		tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
-		return PT_MUNGE_MSR(tmp, task);
+		return tmp | task->thread.fpexc_mode;
 	}
  
 	if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
@@ -273,6 +285,27 @@
 	}
 	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
 }
+
+#ifdef CONFIG_PPC64
+static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
+			       unsigned long data)
+{
+	/* We only support one DABR and no IABRS at the moment */
+	if (addr > 0)
+		return -EINVAL;
+
+	/* The bottom 3 bits are flags */
+	if ((data & ~0x7UL) >= TASK_SIZE)
+		return -EIO;
+
+	/* Ensure translation is on */
+	if (data && !(data & DABR_TRANSLATION))
+		return -EIO;
+
+	task->thread.dabr = data;
+	return 0;
+}
+#endif
  
 /*
  * Called by kernel/ptrace.c when detaching..
@@ -33,8 +33,6 @@
 #include <asm/pgtable.h>
 #include <asm/system.h>
  
-#include "ptrace-ppc64.h"
-
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
1		-/*
2		- * Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
3		- * Extracted from ptrace.c and ptrace32.c
4		- *
5		- * This file is subject to the terms and conditions of the GNU General
6		- * Public License. See the file README.legal in the main directory of
7		- * this archive for more details.
8		- */
9		-
10		-#ifndef _POWERPC_PTRACE_PPC32_H
11		-#define _POWERPC_PTRACE_PPC32_H
12		-
13		-/*
14		- * Set of msr bits that gdb can change on behalf of a process.
15		- */
16		-#if defined(CONFIG_40x) \|\| defined(CONFIG_BOOKE)
17		-#define MSR_DEBUGCHANGE 0
18		-#else
19		-#define MSR_DEBUGCHANGE (MSR_SE \| MSR_BE)
20		-#endif
21		-
22		-/*
23		- * Max register writeable via put_reg
24		- */
25		-#define PT_MAX_PUT_REG PT_MQ
26		-
27		-/*
28		- * Munging of MSR on return from get_regs
29		- *
30		- * Nothing to do on ppc32
31		- */
32		-#define PT_MUNGE_MSR(msr, task) (msr)
33		-
34		-
35		-#endif /* _POWERPC_PTRACE_PPC32_H */
1		-/*
2		- * Copyright (c) 2002 Stephen Rothwell, IBM Coproration
3		- * Extracted from ptrace.c and ptrace32.c
4		- *
5		- * This file is subject to the terms and conditions of the GNU General
6		- * Public License. See the file README.legal in the main directory of
7		- * this archive for more details.
8		- */
9		-
10		-#ifndef _POWERPC_PTRACE_PPC64_H
11		-#define _POWERPC_PTRACE_PPC64_H
12		-
13		-/*
14		- * Set of msr bits that gdb can change on behalf of a process.
15		- */
16		-#define MSR_DEBUGCHANGE (MSR_FE0 \| MSR_SE \| MSR_BE \| MSR_FE1)
17		-
18		-/*
19		- * Max register writeable via put_reg
20		- */
21		-#define PT_MAX_PUT_REG PT_CCR
22		-
23		-/*
24		- * Munging of MSR on return from get_regs
25		- *
26		- * Put the correct FP bits in, they might be wrong as a result
27		- * of our lazy FP restore.
28		- */
29		-
30		-#define PT_MUNGE_MSR(msr, task) ({ (msr) \| (task)->thread.fpexc_mode; })
31		-
32		-static inline int ptrace_set_debugreg(struct task_struct *task,
33		- unsigned long addr, unsigned long data)
34		-{
35		- /* We only support one DABR and no IABRS at the moment */
36		- if (addr > 0)
37		- return -EINVAL;
38		-
39		- /* The bottom 3 bits are flags */
40		- if ((data & ~0x7UL) >= TASK_SIZE)
41		- return -EIO;
42		-
43		- /* Ensure translation is on */
44		- if (data && !(data & DABR_TRANSLATION))
45		- return -EIO;
46		-
47		- task->thread.dabr = data;
48		- return 0;
49		-}
50		-
51		-#endif /* _POWERPC_PTRACE_PPC64_H */
...	...	@@ -35,16 +35,28 @@
35	35	#include <asm/pgtable.h>
36	36	#include <asm/system.h>
37	37
38		-#ifdef CONFIG_PPC64
39		-#include "ptrace-ppc64.h"
	38	+/*
	39	+ * does not yet catch signals sent when the child dies.
	40	+ * in exit.c or in signal.c.
	41	+ */
	42	+
	43	+/*
	44	+ * Set of msr bits that gdb can change on behalf of a process.
	45	+ */
	46	+#if defined(CONFIG_40x) \|\| defined(CONFIG_BOOKE)
	47	+#define MSR_DEBUGCHANGE 0
40	48	#else
41		-#include "ptrace-ppc32.h"
	49	+#define MSR_DEBUGCHANGE (MSR_SE \| MSR_BE)
42	50	#endif
43	51
44	52	/*
45		- * does not yet catch signals sent when the child dies.
46		- * in exit.c or in signal.c.
	53	+ * Max register writeable via put_reg
47	54	*/
	55	+#ifdef CONFIG_PPC32
	56	+#define PT_MAX_PUT_REG PT_MQ
	57	+#else
	58	+#define PT_MAX_PUT_REG PT_CCR
	59	+#endif
48	60
49	61	/*
50	62	* Get contents of register REGNO in task TASK.
...	...	@@ -58,7 +70,7 @@
58	70
59	71	if (regno == PT_MSR) {
60	72	tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
61		- return PT_MUNGE_MSR(tmp, task);
	73	+ return tmp \| task->thread.fpexc_mode;
62	74	}
63	75
64	76	if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
...	...	@@ -273,6 +285,27 @@
273	285	}
274	286	clear_tsk_thread_flag(task, TIF_SINGLESTEP);
275	287	}
	288	+
	289	+#ifdef CONFIG_PPC64
	290	+static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
	291	+ unsigned long data)
	292	+{
	293	+ /* We only support one DABR and no IABRS at the moment */
	294	+ if (addr > 0)
	295	+ return -EINVAL;
	296	+
	297	+ /* The bottom 3 bits are flags */
	298	+ if ((data & ~0x7UL) >= TASK_SIZE)
	299	+ return -EIO;
	300	+
	301	+ /* Ensure translation is on */
	302	+ if (data && !(data & DABR_TRANSLATION))
	303	+ return -EIO;
	304	+
	305	+ task->thread.dabr = data;
	306	+ return 0;
	307	+}
	308	+#endif
276	309
277	310	/*
278	311	* Called by kernel/ptrace.c when detaching..
...	...	@@ -33,8 +33,6 @@
33	33	#include <asm/pgtable.h>
34	34	#include <asm/system.h>
35	35
36		-#include "ptrace-ppc64.h"
37		-
38	36	/*
39	37	* does not yet catch signals sent when the child dies.
40	38	* in exit.c or in signal.c.