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authorJason Wessel <jason.wessel@windriver.com>2011-09-21 22:07:47 +0200
committerJason Wessel <jason.wessel@windriver.com>2012-03-22 21:07:16 +0100
commit1ba0c1720eb0de2d0f3abf84c0b128d10af520d1 (patch)
tree47515d331a39e868510266d72f29267b30b00399 /kernel/debug
parentkdb: Avoid using dbg_io_ops until it is initialized (diff)
downloadlinux-1ba0c1720eb0de2d0f3abf84c0b128d10af520d1.tar.xz
linux-1ba0c1720eb0de2d0f3abf84c0b128d10af520d1.zip
kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint
On x86, if CONFIG_DEBUG_RODATA is set, one cannot set breakpoints via KDB. Apparently this is a well-known problem, as at least one distribution now ships with both KDB enabled and CONFIG_DEBUG_RODATA=y for security reasons. This patch adds an printk message to the breakpoint failure case, in order to provide suggestions about how to use the debugger. Reported-by: Tim Bird <tim.bird@am.sony.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Tim Bird <tim.bird@am.sony.com>
Diffstat (limited to 'kernel/debug')
-rw-r--r--kernel/debug/kdb/kdb_bp.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 20059ef4459a..8418c2f8ec5d 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -153,6 +153,13 @@ static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
} else {
kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
__func__, bp->bp_addr);
+#ifdef CONFIG_DEBUG_RODATA
+ if (!bp->bp_type) {
+ kdb_printf("Software breakpoints are unavailable.\n"
+ " Change the kernel CONFIG_DEBUG_RODATA=n\n"
+ " OR use hw breaks: help bph\n");
+ }
+#endif
return 1;
}
return 0;