diff options
| author | Jordan Niethe <jniethe5@gmail.com> | 2020-05-06 13:40:46 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-05-19 00:11:03 +1000 |
| commit | c9c831aebd8663d0129bbcee4d76be889f0627fe (patch) | |
| tree | f03c984be94460f1d9a58239ceea3786c3cd8652 /arch/powerpc/xmon | |
| parent | 785b79d1e02873c2088ee1301154c66dace66ce5 (diff) | |
powerpc/xmon: Don't allow breakpoints on suffixes
Do not allow placing xmon breakpoints on the suffix of a prefix
instruction.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Don't split printf strings across lines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-27-jniethe5@gmail.com
Diffstat (limited to 'arch/powerpc/xmon')
| -rw-r--r-- | arch/powerpc/xmon/xmon.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index ac8ccf333d51..d1a79f9e0566 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -889,8 +889,8 @@ static struct bpt *new_breakpoint(unsigned long a) static void insert_bpts(void) { int i; - struct ppc_inst instr; - struct bpt *bp; + struct ppc_inst instr, instr2; + struct bpt *bp, *bp2; bp = bpts; for (i = 0; i < NBPTS; ++i, ++bp) { @@ -908,6 +908,29 @@ static void insert_bpts(void) bp->enabled = 0; continue; } + /* + * Check the address is not a suffix by looking for a prefix in + * front of it. + */ + if (mread_instr(bp->address - 4, &instr2) == 8) { + printf("Breakpoint at %lx is on the second word of a prefixed instruction, disabling it\n", + bp->address); + bp->enabled = 0; + continue; + } + /* + * We might still be a suffix - if the prefix has already been + * replaced by a breakpoint we won't catch it with the above + * test. + */ + bp2 = at_breakpoint(bp->address - 4); + if (bp2 && ppc_inst_prefixed(ppc_inst_read(bp2->instr))) { + printf("Breakpoint at %lx is on the second word of a prefixed instruction, disabling it\n", + bp->address); + bp->enabled = 0; + continue; + } + patch_instruction(bp->instr, instr); patch_instruction((void *)bp->instr + ppc_inst_len(instr), ppc_inst(bpinstr)); |