Since it doesn't make sense both to set kgdb_may_fault flag before setting up
the jump buffer and to resotre the preempt count if a fault hasn't happened,
get rid of kgdb_[un]set_may_fault() introducing the inline wrapper around
kgdb_fault_setjmp() call to enable the kernel faults and save/restore the
preempt count if the preemption is enabled (removing kgdb_fault_preempt_count
global variable at the same time) and directly clearing kgdb_may_fault on the
normal, non-faulted exit path from the memory manipulation functions...
Also, while at it, do some more cleanups:
- add newlines after block declarations;
- get rid of unneeded braces;
- clean up grammar/style in comments...
Signed-off-by: Sergei Shtylyov <[EMAIL PROTECTED]>
---
Just remembered that I intended to add newlines after block decrations. :-)
The patch is against the linux_2_6_21_uprev branch as usual...
kernel/kgdb.c | 120 +++++++++++++++++++++++++++++++---------------------------
1 files changed, 65 insertions(+), 55 deletions(-)
Index: linux-2.6/kernel/kgdb.c
===================================================================
--- linux-2.6.orig/kernel/kgdb.c
+++ linux-2.6/kernel/kgdb.c
@@ -10,6 +10,7 @@
* Copyright (C) 2004-2006 Tom Rini <[EMAIL PROTECTED]>
* Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
* Copyright (C) 2005-2007 Wind River Systems, Inc.
+ * Copyright (C) 2007 MontaVista Software, Inc.
*
* Contributors at various stages not listed above:
* Jason Wessel ( [EMAIL PROTECTED] )
@@ -65,12 +66,9 @@ extern int pid_max;
int kgdb_initialized;
/* Is a host GDB connected to us? */
int kgdb_connected;
-/* Could we be about to try and access a bad memory location? If so we
- * also need to flag this has happend. */
+/* Could we be about to try and access a bad memory location?
+ * If so we also need to flag this has happened. */
int kgdb_may_fault;
-#ifdef CONFIG_PREEMPT
-static int kgdb_fault_preempt_count;
-#endif
/* All the KGDB handlers are installed */
int kgdb_from_module_registered = 0;
@@ -196,6 +194,7 @@ static void get_packet(char *buffer)
unsigned char xmitcsum;
int count;
char ch;
+
if (!kgdb_io_ops.read_char)
return;
do {
@@ -235,20 +234,6 @@ static void get_packet(char *buffer)
} while (checksum != xmitcsum);
}
-static void kgdb_set_may_fault(void) {
- kgdb_may_fault = 1;
-#ifdef CONFIG_PREEMPT
- kgdb_fault_preempt_count = preempt_count();
-#endif
-}
-
-static void kgdb_unset_may_fault(void) {
- kgdb_may_fault = 0;
-#ifdef CONFIG_PREEMPT
- preempt_count() = kgdb_fault_preempt_count;
-#endif
-}
-
/*
* Send the packet in buffer.
* Check for gdb connection if asked for.
@@ -303,21 +288,48 @@ static void put_packet(char *buffer)
}
/*
- * convert the memory pointed to by mem into hex, placing result in buf
- * return a pointer to the last char put in buf (null). May return an error.
+ * Wrap kgdb_fault_setjmp() call to enable the kernel faults and save/restore
+ * the state before/after a fault has happened.
+ * Note that it *must* be inline to work correctly.
+ */
+static inline int fault_setjmp(void)
+{
+#ifdef CONFIG_PREEMPT
+ int count = preempt_count();
+#endif
+
+ /*
+ * kgdb_fault_setjmp() returns 0 after the jump buffer has been setup,
+ * and non-zero when an expected kernel fault has happened.
+ */
+ if (kgdb_fault_setjmp(kgdb_fault_jmp_regs) == 0) {
+ kgdb_may_fault = 1;
+ return 0;
+ } else {
+#ifdef CONFIG_PREEMPT
+ preempt_count() = count;
+#endif
+ kgdb_may_fault = 0;
+ return 1;
+ }
+}
+
+/*
+ * Convert the memory pointed to by mem into hex, placing result in buf.
+ * Return a pointer to the last char put in buf (null). May return an error.
*/
char *kgdb_mem2hex(char *mem, char *buf, int count)
{
- kgdb_set_may_fault();
- if ((kgdb_fault_setjmp(kgdb_fault_jmp_regs)) != 0) {
- kgdb_unset_may_fault();
+ if (fault_setjmp() != 0)
return ERR_PTR(-EINVAL);
- }
- /* Accessing some registers in a single load instruction is
+
+ /*
+ * Accessing some registers in a single load instruction is
* required to avoid bad side effects for some I/O registers.
*/
if ((count == 2) && (((long)mem & 1) == 0)) {
unsigned short tmp_s = *(unsigned short *)mem;
+
mem += 2;
#ifdef __BIG_ENDIAN
*buf++ = hexchars[(tmp_s >> 12) & 0xf];
@@ -332,6 +344,7 @@ char *kgdb_mem2hex(char *mem, char *buf,
#endif
} else if ((count == 4) && (((long)mem & 3) == 0)) {
unsigned long tmp_l = *(unsigned int *)mem;
+
mem += 4;
#ifdef __BIG_ENDIAN
*buf++ = hexchars[(tmp_l >> 28) & 0xf];
@@ -355,6 +368,7 @@ char *kgdb_mem2hex(char *mem, char *buf,
#ifdef CONFIG_64BIT
} else if ((count == 8) && (((long)mem & 7) == 0)) {
unsigned long long tmp_ll = *(unsigned long long *)mem;
+
mem += 8;
#ifdef __BIG_ENDIAN
*buf++ = hexchars[(tmp_ll >> 60) & 0xf];
@@ -392,14 +406,14 @@ char *kgdb_mem2hex(char *mem, char *buf,
*buf++ = hexchars[(tmp_ll >> 56) & 0xf];
#endif
#endif
- } else {
+ } else
while (count-- > 0) {
unsigned char ch = *mem++;
+
*buf++ = hexchars[ch >> 4];
*buf++ = hexchars[ch & 0xf];
}
- }
- kgdb_unset_may_fault();
+ kgdb_may_fault = 0;
*buf = 0;
return (buf);
}
@@ -411,35 +425,32 @@ char *kgdb_mem2hex(char *mem, char *buf,
*/
static char *kgdb_ebin2mem(char *buf, char *mem, int count)
{
- kgdb_set_may_fault();
- if ((kgdb_fault_setjmp(kgdb_fault_jmp_regs)) != 0) {
- kgdb_unset_may_fault();
+ if (fault_setjmp() != 0)
return ERR_PTR(-EINVAL);
- }
- for (; count > 0; count--, buf++) {
+
+ for (; count > 0; count--, buf++)
if (*buf == 0x7d)
*mem++ = *(++buf) ^ 0x20;
else
*mem++ = *buf;
- }
- kgdb_unset_may_fault();
+
+ kgdb_may_fault = 0;
return mem;
}
/*
- * convert the hex array pointed to by buf into binary to be placed in mem
- * return a pointer to the character AFTER the last byte written
+ * Convert the hex array pointed to by buf into binary to be placed in mem.
+ * Return a pointer to the character AFTER the last byte written.
* May return an error.
*/
char *kgdb_hex2mem(char *buf, char *mem, int count)
{
- kgdb_set_may_fault();
- if ((kgdb_fault_setjmp(kgdb_fault_jmp_regs)) != 0) {
- kgdb_unset_may_fault();
+ if (fault_setjmp() != 0)
return ERR_PTR(-EINVAL);
- }
+
if ((count == 2) && (((long)mem & 1) == 0)) {
unsigned short tmp_s = 0;
+
#ifdef __BIG_ENDIAN
tmp_s |= hex(*buf++) << 12;
tmp_s |= hex(*buf++) << 8;
@@ -455,6 +466,7 @@ char *kgdb_hex2mem(char *buf, char *mem,
mem += 2;
} else if ((count == 4) && (((long)mem & 3) == 0)) {
unsigned long tmp_l = 0;
+
#ifdef __BIG_ENDIAN
tmp_l |= hex(*buf++) << 28;
tmp_l |= hex(*buf++) << 24;
@@ -478,13 +490,15 @@ char *kgdb_hex2mem(char *buf, char *mem,
mem += 4;
} else {
int i;
+
for (i = 0; i < count; i++) {
unsigned char ch = hex(*buf++) << 4;
+
ch |= hex(*buf++);
*mem++ = ch;
}
}
- kgdb_unset_may_fault();
+ kgdb_may_fault = 0;
return (mem);
}
@@ -639,39 +653,35 @@ static void kgdb_wait(struct pt_regs *re
int kgdb_get_mem(char *addr, unsigned char *buf, int count)
{
- kgdb_set_may_fault();
- if ((kgdb_fault_setjmp(kgdb_fault_jmp_regs)) != 0) {
- kgdb_unset_may_fault();
+ if (fault_setjmp() != 0)
return -EINVAL;
- }
+
while (count) {
if ((unsigned long)addr < TASK_SIZE) {
- kgdb_unset_may_fault();
+ kgdb_may_fault = 0;
return -EINVAL;
}
*buf++ = *addr++;
count--;
}
- kgdb_unset_may_fault();
+ kgdb_may_fault = 0;
return 0;
}
int kgdb_set_mem(char *addr, unsigned char *buf, int count)
{
- kgdb_set_may_fault();
- if ((kgdb_fault_setjmp(kgdb_fault_jmp_regs)) != 0) {
- kgdb_unset_may_fault();
+ if (fault_setjmp() != 0)
return -EINVAL;
- }
+
while (count) {
if ((unsigned long)addr < TASK_SIZE) {
- kgdb_unset_may_fault();
+ kgdb_may_fault = 0;
return -EINVAL;
}
*addr++ = *buf++;
count--;
}
- kgdb_unset_may_fault();
+ kgdb_may_fault = 0;
return 0;
}
int kgdb_activate_sw_breakpoints(void)
-------------------------------------------------------------------------
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