Hi Keith,
Your recent patch looks to break module kallsyms lookups. On ppc64
current -bk shows this in an oops:
Oops: Exception in kernel mode, sig: 5 [#1]
...
NIP [d000000000036028] __bss_stop+0xfffffffff84f368/0x340
LR [d000000000036024] __bss_stop+0xfffffffff84f364/0x340
Call Trace:
[c00000000231fd10] [d000000000036024] __bss_stop+0xfffffffff84f364/0x340 (unreliable)
[c00000000231fd90] [c000000000078750] .sys_init_module+0x2fc/0x4d8
[c00000000231fe30] [c00000000000d500] syscall_exit+0x0/0x18
Backing out the patch below, things work as expected:
Oops: Exception in kernel mode, sig: 5 [#1]
...
NIP [d000000000036028] .myinit+0x28/0x44 [mod]
LR [d000000000036024] .myinit+0x24/0x44 [mod]
Call Trace:
[c000000002313d10] [d000000000036024] .myinit+0x24/0x44 [mod] (unreliable)
[c000000002313d90] [c000000000078750] .sys_init_module+0x2fc/0x4d8
[c000000002313e30] [c00000000000d500] syscall_exit+0x0/0x18
It looks like if CONFIG_KALLSYMS_ALL is set then we never look up module
addresses.
Anton
# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2004/12/28 22:16:26+01:00 [email protected]
# kallsyms: gate page is part of the kernel, honour CONFIG_KALLSYMS_ALL
#
# * Treat the gate page as part of the kernel, to improve kernel backtraces.
#
# * Honour CONFIG_KALLSYMS_ALL, all symbols are valid, not just text.
#
# Signed-off-by: Keith Owens <[email protected]>
# Signed-off-by: Sam Ravnborg <[email protected]>
#
# kernel/kallsyms.c
# 2004/11/28 04:42:24+01:00 [email protected] +11 -4
# kallsyms: gate page is part of the kernel, honour CONFIG_KALLSYMS_ALL
#
diff -Nru a/kernel/kallsyms.c b/kernel/kallsyms.c
--- a/kernel/kallsyms.c 2005-01-10 22:01:10 +11:00
+++ b/kernel/kallsyms.c 2005-01-10 22:01:10 +11:00
@@ -18,6 +18,13 @@
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/proc_fs.h>
+#include <linux/mm.h>
+
+#ifdef CONFIG_KALLSYMS_ALL
+#define all_var 1
+#else
+#define all_var 0
+#endif
/* These will be re-linked against their real values during the second link stage */
extern unsigned long kallsyms_addresses[] __attribute__((weak));
@@ -30,7 +37,7 @@
extern unsigned long kallsyms_markers[] __attribute__((weak));
/* Defined by the linker script. */
-extern char _stext[], _etext[], _sinittext[], _einittext[];
+extern char _stext[], _etext[], _sinittext[], _einittext[], _end[];
static inline int is_kernel_inittext(unsigned long addr)
{
@@ -44,7 +51,7 @@
{
if (addr >= (unsigned long)_stext && addr <= (unsigned long)_etext)
return 1;
- return 0;
+ return in_gate_area_no_task(addr);
}
/* expand a compressed symbol data into the resulting uncompressed string,
@@ -147,7 +154,7 @@
namebuf[KSYM_NAME_LEN] = 0;
namebuf[0] = 0;
- if (is_kernel_text(addr) || is_kernel_inittext(addr)) {
+ if (all_var || is_kernel_text(addr) || is_kernel_inittext(addr)) {
unsigned long symbol_end=0;
/* do a binary search on the sorted kallsyms_addresses array */
@@ -181,7 +188,7 @@
if (is_kernel_inittext(addr))
symbol_end = (unsigned long)_einittext;
else
- symbol_end = (unsigned long)_etext;
+ symbol_end = all_var ? (unsigned long)_end : (unsigned long)_etext;
}
*symbolsize = symbol_end - kallsyms_addresses[low];
On Mon, 10 Jan 2005 22:13:37 +1100,
Anton Blanchard <[email protected]> wrote:
>Your recent patch looks to break module kallsyms lookups....
>It looks like if CONFIG_KALLSYMS_ALL is set then we never look up module
>addresses.
Separate lookups for kernel and modules when CONFIG_KALLSYMS_ALL=y.
Signed-off-by: Keith Owens <[email protected]>
Index: 2.6.10-bk13/kernel/kallsyms.c
===================================================================
--- 2.6.10-bk13.orig/kernel/kallsyms.c 2005-01-11 00:42:19.600615731 +1100
+++ 2.6.10-bk13/kernel/kallsyms.c 2005-01-11 00:42:41.520243100 +1100
@@ -53,6 +53,13 @@ static inline int is_kernel_text(unsigne
return in_gate_area_no_task(addr);
}
+static inline int is_kernel(unsigned long addr)
+{
+ if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
+ return 1;
+ return in_gate_area_no_task(addr);
+}
+
/* expand a compressed symbol data into the resulting uncompressed string,
given the offset to where the symbol is in the compressed stream */
static unsigned int kallsyms_expand_symbol(unsigned int off, char *result)
@@ -153,7 +160,8 @@ const char *kallsyms_lookup(unsigned lon
namebuf[KSYM_NAME_LEN] = 0;
namebuf[0] = 0;
- if (all_var || is_kernel_text(addr) || is_kernel_inittext(addr)) {
+ if ((all_var && is_kernel(addr)) ||
+ (!all_var && (is_kernel_text(addr) || is_kernel_inittext(addr)))) {
unsigned long symbol_end=0;
/* do a binary search on the sorted kallsyms_addresses array */
On Tue, Jan 11, 2005 at 12:44:29AM +1100, Keith Owens wrote:
> On Mon, 10 Jan 2005 22:13:37 +1100,
> Anton Blanchard <[email protected]> wrote:
> >Your recent patch looks to break module kallsyms lookups....
> >It looks like if CONFIG_KALLSYMS_ALL is set then we never look up module
> >addresses.
>
> Separate lookups for kernel and modules when CONFIG_KALLSYMS_ALL=y.
Applied
Sam