From 4f7c06e26ec9cf7fe9f0c54dc90079b6a4f4b2c3 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Thu, 17 May 2018 15:37:15 +1000 Subject: powerpc/ptrace: Fix setting 512B aligned breakpoints with PTRACE_SET_DEBUGREG In commit e2a800beaca1 ("powerpc/hw_brk: Fix off by one error when validating DAWR region end") we fixed setting the DAWR end point to its max value via PPC_PTRACE_SETHWDEBUG. Unfortunately we broke PTRACE_SET_DEBUGREG when setting a 512 byte aligned breakpoint. PTRACE_SET_DEBUGREG currently sets the length of the breakpoint to zero (memset() in hw_breakpoint_init()). This worked with arch_validate_hwbkpt_settings() before the above patch was applied but is now broken if the breakpoint is 512byte aligned. This sets the length of the breakpoint to 8 bytes when using PTRACE_SET_DEBUGREG. Fixes: e2a800beaca1 ("powerpc/hw_brk: Fix off by one error when validating DAWR region end") Cc: stable@vger.kernel.org # v3.11+ Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/ptrace.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc/kernel/ptrace.c') diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index d23cf632edf0..0f63dd5972e9 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -2443,6 +2443,7 @@ static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, /* Create a new breakpoint request if one doesn't exist already */ hw_breakpoint_init(&attr); attr.bp_addr = hw_brk.address; + attr.bp_len = 8; arch_bp_generic_fields(hw_brk.type, &attr.bp_type); -- cgit v1.2.3-59-g8ed1b