diff options
| -rw-r--r-- | gdb/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/btrace.c | 22 |
2 files changed, 18 insertions, 9 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 98e13ea..2a601a9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,10 @@ 2016-10-28 Markus Metzger <markus.t.metzger@intel.com> + * btrace.c (ftrace_new_return): Start from the previous function's + level if we can't find a matching call for a return. + +2016-10-28 Markus Metzger <markus.t.metzger@intel.com> + * btrace.c (ftrace_update_function): Update tail call heuristic. 2016-10-28 Markus Metzger <markus.t.metzger@intel.com> diff --git a/gdb/btrace.c b/gdb/btrace.c index 445f0a4..10b6db4 100644 --- a/gdb/btrace.c +++ b/gdb/btrace.c @@ -387,16 +387,12 @@ ftrace_new_return (struct btrace_function *prev, /* There is no call in PREV's back trace. We assume that the branch trace did not include it. */ - /* Let's find the topmost call function - this skips tail calls. */ + /* Let's find the topmost function and add a new caller for it. + This should handle a series of initial tail calls. */ while (prev->up != NULL) prev = prev->up; - /* We maintain levels for a series of returns for which we have - not seen the calls. - We start at the preceding function's level in case this has - already been a return for which we have not seen the call. - We start at level 0 otherwise, to handle tail calls correctly. */ - bfun->level = std::min (0, prev->level) - 1; + bfun->level = prev->level - 1; /* Fix up the call stack for PREV. */ ftrace_fixup_caller (prev, bfun, BFUN_UP_LINKS_TO_RET); @@ -406,8 +402,16 @@ ftrace_new_return (struct btrace_function *prev, else { /* There is a call in PREV's back trace to which we should have - returned. Let's remain at this level. */ - bfun->level = prev->level; + returned but didn't. Let's start a new, separate back trace + from PREV's level. */ + bfun->level = prev->level - 1; + + /* We fix up the back trace for PREV but leave other function segments + on the same level as they are. + This should handle things like schedule () correctly where we're + switching contexts. */ + prev->up = bfun; + prev->flags = BFUN_UP_LINKS_TO_RET; ftrace_debug (bfun, "new return - unknown caller"); } |