From: Michael Neuling Date: Thu, 17 May 2018 05:37:15 +0000 (+1000) Subject: powerpc/ptrace: Fix setting 512B aligned breakpoints with PTRACE_SET_DEBUGREG X-Git-Tag: v4.18-rc1~108^2~161 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4f7c06e26e;p=thirdparty%2Flinux.git 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 --- diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index d23cf632edf06..0f63dd5972e9a 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);