Le 28/04/2020 à 07:30, Jordan Niethe a écrit :
On Tue, Apr 28, 2020 at 3:20 PM Christophe Leroy
<christophe.le...@c-s.fr> wrote:
Le 28/04/2020 à 03:57, Jordan Niethe a écrit :
The instructions for xmon's breakpoint are stored bpt_table[] which is in
the data section. This is problematic as the data section may be marked
as no execute. Move bpt_table[] to the text section.
Signed-off-by: Jordan Niethe <jniet...@gmail.com>
---
v6: - New to series. Was part of the previous patch.
- Make BPT_SIZE available in assembly
---
arch/powerpc/kernel/asm-offsets.c | 8 ++++++++
arch/powerpc/xmon/Makefile | 2 +-
arch/powerpc/xmon/xmon.c | 6 +-----
arch/powerpc/xmon/xmon_bpts.S | 9 +++++++++
arch/powerpc/xmon/xmon_bpts.h | 14 ++++++++++++++
5 files changed, 33 insertions(+), 6 deletions(-)
create mode 100644 arch/powerpc/xmon/xmon_bpts.S
create mode 100644 arch/powerpc/xmon/xmon_bpts.h
diff --git a/arch/powerpc/kernel/asm-offsets.c
b/arch/powerpc/kernel/asm-offsets.c
index c25e562f1cd9..2401f415f423 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -70,6 +70,10 @@
#include <asm/fixmap.h>
#endif
+#ifdef CONFIG_XMON
+#include "../xmon/xmon_bpts.h"
+#endif
+
#define STACK_PT_REGS_OFFSET(sym, val) \
DEFINE(sym, STACK_FRAME_OVERHEAD + offsetof(struct pt_regs, val))
@@ -783,5 +787,9 @@ int main(void)
DEFINE(VIRT_IMMR_BASE, (u64)__fix_to_virt(FIX_IMMR_BASE));
#endif
+#ifdef CONFIG_XMON
+ DEFINE(BPT_SIZE, BPT_SIZE);
+#endif
+
return 0;
}
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index c3842dbeb1b7..515a13ea6f28 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -21,7 +21,7 @@ endif
ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
-obj-y += xmon.o nonstdio.o spr_access.o
+obj-y += xmon.o nonstdio.o spr_access.o xmon_bpts.o
ifdef CONFIG_XMON_DISASSEMBLY
obj-y += ppc-dis.o ppc-opc.o
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index a064392df1b8..f7ce3ea8694c 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -62,6 +62,7 @@
#include "nonstdio.h"
#include "dis-asm.h"
+#include "xmon_bpts.h"
#ifdef CONFIG_SMP
static cpumask_t cpus_in_xmon = CPU_MASK_NONE;
@@ -108,7 +109,6 @@ struct bpt {
#define BP_TRAP 2
#define BP_DABR 4
-#define NBPTS 256
static struct bpt bpts[NBPTS];
static struct bpt dabr;
static struct bpt *iabr;
@@ -116,10 +116,6 @@ static unsigned bpinstr = 0x7fe00008; /* trap */
#define BP_NUM(bp) ((bp) - bpts + 1)
-#define BPT_SIZE (sizeof(unsigned int) * 2)
-#define BPT_WORDS (BPT_SIZE / sizeof(unsigned int))
-static unsigned int bpt_table[NBPTS * BPT_WORDS];
-
/* Prototypes */
static int cmds(struct pt_regs *);
static int mread(unsigned long, void *, int);
diff --git a/arch/powerpc/xmon/xmon_bpts.S b/arch/powerpc/xmon/xmon_bpts.S
new file mode 100644
index 000000000000..f3ad0ab50854
--- /dev/null
+++ b/arch/powerpc/xmon/xmon_bpts.S
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/ppc_asm.h>
+#include <asm/asm-compat.h>
+#include <asm/asm-offsets.h>
+#include "xmon_bpts.h"
+
+.global bpt_table
+bpt_table:
+ .space NBPTS * BPT_SIZE
No alignment required ? Standard alignment (probably 4 bytes ?) is
acceptable ?
No, I'll add a .balign 4 to be sure.
I think it is aligned to 4 by default. My question was to know whether 4
is enough.
I see BPT_SIZE is 8, should the alignment be at least 8 ?
diff --git a/arch/powerpc/xmon/xmon_bpts.h b/arch/powerpc/xmon/xmon_bpts.h
new file mode 100644
index 000000000000..b7e94375db86
--- /dev/null
+++ b/arch/powerpc/xmon/xmon_bpts.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef XMON_BPTS_H
+#define XMON_BPTS_H
+
+#define NBPTS 256
+#ifndef __ASSEMBLY__
+#define BPT_SIZE (sizeof(unsigned int) * 2)
+#define BPT_WORDS (BPT_SIZE / sizeof(unsigned int))
+
+extern unsigned int bpt_table[NBPTS * BPT_WORDS];
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* XMON_BPTS_H */
Christophe
