From c9f568f1a99794aa7b749828c41fb7cdf55fe435 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 23 Mar 2012 09:35:05 -0500 Subject: x86,kgdb: Fix DEBUG_RODATA limitation using text_poke() commit 3751d3e85cf693e10e2c47c03c8caa65e171099b upstream. There has long been a limitation using software breakpoints with a kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For this particular patch, it will apply cleanly and has been tested all the way back to 2.6.36. The kprobes code uses the text_poke() function which accommodates writing a breakpoint into a read-only page. The x86 kgdb code can solve the problem similarly by overriding the default breakpoint set/remove routines and using text_poke() directly. The x86 kgdb code will first attempt to use the traditional probe_kernel_write(), and next try using a the text_poke() function. The break point install method is tracked such that the correct break point removal routine will get called later on. Cc: x86@kernel.org Cc: Thomas Gleixner Cc: Ingo Molnar Cc: H. Peter Anvin Inspried-by: Masami Hiramatsu Signed-off-by: Jason Wessel Signed-off-by: Greg Kroah-Hartman --- include/linux/kgdb.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index e5d689c1d77..c4d2fc194ed 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -63,7 +63,8 @@ enum kgdb_bptype { BP_HARDWARE_BREAKPOINT, BP_WRITE_WATCHPOINT, BP_READ_WATCHPOINT, - BP_ACCESS_WATCHPOINT + BP_ACCESS_WATCHPOINT, + BP_POKE_BREAKPOINT, }; enum kgdb_bpstate { -- cgit v1.2.3-18-g5258