From 7daf59300999693b85233762b847f1b2313cccbd Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Wed, 23 May 2018 20:00:54 +0200 Subject: powerpc/xmon: Also setup debugger hooks when single-stepping When single-stepping kernel code from xmon without a debug hook enabled the kernel crashes. This can happen when kernel starts with xmon on crash disabled but xmon is entered using sysrq. Call force_enable_xmon when single-stepping in xmon to install the xmon debug hooks. Fixes: e1368d0c9edb ("powerpc/xmon: Setup debugger hooks when first break-point is set") Signed-off-by: Michal Suchanek Reviewed-by: Vaibhav Jain Signed-off-by: Michael Ellerman --- arch/powerpc/xmon/xmon.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'arch/powerpc/xmon') diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index a0842f1ff72c..252df9741d20 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -778,6 +778,16 @@ static int xmon_fault_handler(struct pt_regs *regs) return 0; } +/* Force enable xmon if not already enabled */ +static inline void force_enable_xmon(void) +{ + /* Enable xmon hooks if needed */ + if (!xmon_on) { + printf("xmon: Enabling debugger hooks\n"); + xmon_on = 1; + } +} + static struct bpt *at_breakpoint(unsigned long pc) { int i; @@ -1094,6 +1104,7 @@ static int do_step(struct pt_regs *regs) unsigned int instr; int stepped; + force_enable_xmon(); /* check we are in 64-bit kernel mode, translation enabled */ if ((regs->msr & (MSR_64BIT|MSR_PR|MSR_IR)) == (MSR_64BIT|MSR_IR)) { if (mread(regs->nip, &instr, 4) == 4) { @@ -1268,16 +1279,6 @@ static long check_bp_loc(unsigned long addr) return 1; } -/* Force enable xmon if not already enabled */ -static inline void force_enable_xmon(void) -{ - /* Enable xmon hooks if needed */ - if (!xmon_on) { - printf("xmon: Enabling debugger hooks\n"); - xmon_on = 1; - } -} - static char *breakpoint_help_string = "Breakpoint command usage:\n" "b show breakpoints\n" -- cgit v1.2.3