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| author | Shahab Vahedi <shahab@synopsys.com> | 2020-11-12 12:50:33 +0100 |
|---|---|---|
| committer | Shahab Vahedi <shahab@synopsys.com> | 2020-11-12 17:00:55 +0100 |
| commit | 10c19fadfd45da5262d2f8b9624be71c274ff15d (patch) | |
| tree | c6b9afc856514699d48d084fa1febb0426d729f9 /gdb | |
| parent | 1f2624a35413c31c317e5da8ce7401b59ecfbfa5 (diff) | |
| download | gdb-10c19fadfd45da5262d2f8b9624be71c274ff15d.zip gdb-10c19fadfd45da5262d2f8b9624be71c274ff15d.tar.gz gdb-10c19fadfd45da5262d2f8b9624be71c274ff15d.tar.bz2 | |
arc: Write correct "eret" value during register collection
In collect_register() function of arc-linux-tdep.c, the "eret"
(exception return) register value was not being reported correctly.
This patch fixes that.
Background:
When asked for the "pc" value, we have to update the "eret" register
with GDB's STOP_PC. The "eret" instructs the kernel code where to
jump back when an instruction has stopped due to a breakpoint. This
is how collect_register() was doing so:
--------------8<--------------
if (regnum == gdbarch_pc_regnum (gdbarch))
regnum = ARC_ERET_REGNUM;
regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]);
-------------->8--------------
Root cause:
Although this is using the correct offset (ERET register's), it is also
changing the REGNUM itself. Therefore, raw_collect (regnum, ...) is
not reading from "pc" anymore.
v2:
- Fix a copy/paste issue as rightfully addressed by Tom [1].
[1]
https://sourceware.org/pipermail/gdb-patches/2020-November/173208.html
gdb/ChangeLog:
* arc-linux-tdep.c (collect_register): Populate "eret" by
"pc" value from the regcache when asked for "pc" value.
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/arc-linux-tdep.c | 10 |
2 files changed, 12 insertions, 3 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 038d45f..4d1f524 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2020-11-12 Shahab Vahedi <shahab@synopsys.com> + + * arc-linux-tdep.c (collect_register): Populate "eret" by + "pc" value from the regcache when asked for "pc" value. + 2020-11-12 Tom Tromey <tom@tromey.com> PR rust/26799: diff --git a/gdb/arc-linux-tdep.c b/gdb/arc-linux-tdep.c index 9ff5f12..6e74bae 100644 --- a/gdb/arc-linux-tdep.c +++ b/gdb/arc-linux-tdep.c @@ -319,8 +319,10 @@ static void collect_register (const struct regcache *regcache, struct gdbarch *gdbarch, int regnum, gdb_byte *buf) { + int offset; + /* Skip non-existing registers. */ - if ((arc_linux_core_reg_offsets[regnum] == ARC_OFFSET_NO_REGISTER)) + if (arc_linux_core_reg_offsets[regnum] == ARC_OFFSET_NO_REGISTER) return; /* The address where the execution has stopped is in pseudo-register @@ -332,8 +334,10 @@ collect_register (const struct regcache *regcache, struct gdbarch *gdbarch, the program will continue at the address after the current instruction. */ if (regnum == gdbarch_pc_regnum (gdbarch)) - regnum = ARC_ERET_REGNUM; - regcache->raw_collect (regnum, buf + arc_linux_core_reg_offsets[regnum]); + offset = arc_linux_core_reg_offsets[ARC_ERET_REGNUM]; + else + offset = arc_linux_core_reg_offsets[regnum]; + regcache->raw_collect (regnum, buf + offset); } void |