Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1ba0c172 authored by Jason Wessel's avatar Jason Wessel
Browse files

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: default avatarTim Bird <tim.bird@am.sony.com>
Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
Acked-by: default avatarTim Bird <tim.bird@am.sony.com>
parent b8adde8d

kernel/debug/kdb/kdb_bp.c

+7 −0
Original line number Diff line number Diff line
@@ -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;