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author | Simon Marchi <simon.marchi@polymtl.ca> | 2021-04-04 22:29:34 -0400 |
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committer | Simon Marchi <simon.marchi@polymtl.ca> | 2021-04-04 22:29:34 -0400 |
commit | 306b445a6d4cc9dbb46ecdf22d9585fe9fc98115 (patch) | |
tree | 909b61ccce75fd48a1593d59bf443c011befa3b4 /gdb | |
parent | a2991571f0d7fdaea813fb6dfe15d19e33364918 (diff) | |
download | binutils-306b445a6d4cc9dbb46ecdf22d9585fe9fc98115.zip binutils-306b445a6d4cc9dbb46ecdf22d9585fe9fc98115.tar.gz binutils-306b445a6d4cc9dbb46ecdf22d9585fe9fc98115.tar.bz2 |
gdb: fix internal error in avr_frame_unwind_cache
When trying to do pretty much anything that requires unwinding a frame
on AVR, we get
/home/simark/src/wt/avr/gdb/trad-frame.h:143: internal-error: LONGEST trad_frame_saved_reg::addr() const: Assertion `m_kind == trad_frame_saved_reg_kind::ADDR' failed.
This is likely coming from the trad-frame refactor in 098caef485a4
("Refactor struct trad_frame_saved_regs"). Here's an example of how to
reproduce it:
In one terminal:
$ cat test.c
int foo(int x)
{
return x * 7;
}
int main() {
return foo(2);
}
$ avr-gcc -gdwarf-4 -mmcu=atmega2560 test.c
$ /tmp/simavr/bin/simavr --mcu atmega2560 -g a.out
Loaded 330 .text at address 0x0
Loaded 0 .data
And in another one:
$ ./gdb -q -nx --data-directory=data-directory a.out -ex "tar rem :1234" -ex "b foo" -ex c -ex bt
Reading symbols from a.out...
Remote debugging using :1234
0x00000000 in __vectors ()
Breakpoint 1 at 0x110: file test.c, line 3.
Note: automatically using hardware breakpoints for read-only addresses.
Continuing.
Breakpoint 1, foo (x=2) at test.c:3
3 return x * 7;
#0 foo (x=2) at test.c:3
/home/simark/src/wt/avr/gdb/trad-frame.h:143: internal-error: LONGEST trad_frame_saved_reg::addr() const: Assertion `m_kind == trad_frame_saved_reg_kind::ADDR' failed.
What the AVR code does is:
1. In avr_scan_prologue, in the block that says "First stage of the
prologue scanning.", look for "push rX" instructions and note that rX
is saved on the stack. But instead of putting the actual stack
address directly, it puts an offset (from the previous frame's sp).
2. Back in avr_frame_unwind_cache, in the block that says "Adjust all
the saved registers", adjust all these values to be real stack
addresses.
To check whether a register was assigned an address (and therefore if it
needs adjustment), the code does:
if (info->saved_regs[i].addr () > 0)
Since commit 098caef485a4, it's invalid to call the `addr` getter of
trad_frame_saved_reg if the register hasn't been assigned an address.
Instead, the code could use the `is_addr` getter to verify if the
register has been assigned an address. This is what this patch does.
gdb/ChangeLog:
* avr-tdep.c (avr_frame_unwind_cache): Use
trad_frame_saved_reg::is_addr.
Change-Id: I5803089160b829400178746c5e3bca0c1cd11c00
Diffstat (limited to 'gdb')
-rw-r--r-- | gdb/ChangeLog | 5 | ||||
-rw-r--r-- | gdb/avr-tdep.c | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 21cd0f0..281c567 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2021-04-04 Simon Marchi <simon.marchi@polymtl.ca> + + * avr-tdep.c (avr_frame_unwind_cache): Use + trad_frame_saved_reg::is_addr. + 2021-04-02 Simon Marchi <simon.marchi@polymtl.ca> * objfiles.c (get_objfile_bfd_data): Remove objfile parameter, diff --git a/gdb/avr-tdep.c b/gdb/avr-tdep.c index 018b18f..5853e69 100644 --- a/gdb/avr-tdep.c +++ b/gdb/avr-tdep.c @@ -1037,7 +1037,7 @@ avr_frame_unwind_cache (struct frame_info *this_frame, /* Adjust all the saved registers so that they contain addresses and not offsets. */ for (i = 0; i < gdbarch_num_regs (gdbarch) - 1; i++) - if (info->saved_regs[i].addr () > 0) + if (info->saved_regs[i].is_addr ()) info->saved_regs[i].set_addr (info->prev_sp - info->saved_regs[i].addr ()); |