Expand the gdb.base/watchpoint-reuse-slot.exp test to be run twice,
once with hardware watchpoints disabled (this is new) and then with
hardware watchpoints enabled (the old way).
Running with hardware watchpoints enabled is skipped if the board file
says that hardware watchpoints are not supported on this target.
gdb/testsuite/ChangeLog:
* gdb.base/watchpoint-reuse-slot.exp: Test with hardware
watchpoints enabled and disabled.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
Hi,
ARM linux kernel has some requirements on the address/length setting
for HW breakpoints/watchpoints, but watchpoint-reuse-slot.exp doesn't
consider them and sets HW points on various addresses. Many fails
are causes as a result:
stepi^M
Warning:^M
Could not insert hardware watchpoint 20.^M
Could not insert hardware breakpoints:^M
You may have requested too many hardware breakpoints/watchpoints.^M
^M
(gdb) FAIL: gdb.base/watchpoint-reuse-slot.exp: always-inserted off: watch x watch: : width 2, iter 2: base + 1: stepi advanced
watch *(buf.byte + 2 + 1)@2^M
Hardware watchpoint 388: *(buf.byte + 2 + 1)@2^M
Warning:^M
Could not insert hardware watchpoint 388.^M
Could not insert hardware breakpoints:^M
You may have requested too many hardware breakpoints/watchpoints.^M
^M
(gdb) FAIL: gdb.base/watchpoint-reuse-slot.exp: always-inserted on: watch x watch: : width 2, iter 2: base + 1: watch *(buf.byte + 2 + 1)@2
This patch is to reflect kernel requirements in watchpoint-reuse-slot.exp
in order to skip some tests.
gdb/testsuite:
2015-04-10 Yao Qi <yao.qi@linaro.org>
* gdb.base/watchpoint-reuse-slot.exp (valid_addr_p): Return
false for some offset and width combinations which aren't
supported by linux kernel.
We see some fails in watchpoint-reuse-slot.exp on aarch64-linux, because
it sets some HW breakpoint on some address doesn't meet the alignment
requirements by kernel, kernel will reject the
ptrace (PTRACE_SETHBPREGS) call, and some fails are caused, for example:
(gdb) PASS: gdb.base/watchpoint-reuse-slot.exp: always-inserted off: watch x hbreak: : width 1, iter 0: base + 0: delete $bpnum
hbreak *(buf.byte + 0 + 1)^M
Hardware assisted breakpoint 80 at 0x410a61^M
(gdb) PASS: gdb.base/watchpoint-reuse-slot.exp: always-inserted off: watch x hbreak: : width 1, iter 0: base + 1: hbreak *(buf.byte + 0 + 1)
stepi^M
Warning:^M
Cannot insert hardware breakpoint 80.^M
Could not insert hardware breakpoints:^M
You may have requested too many hardware breakpoints/watchpoints.^M
^M
(gdb) FAIL: gdb.base/watchpoint-reuse-slot.exp: always-inserted off: watch x hbreak: : width 1, iter 0: base + 1: stepi advanced
hbreak *(buf.byte + 0 + 1)^M
Hardware assisted breakpoint 440 at 0x410a61^M
Warning:^M
Cannot insert hardware breakpoint 440.^M
Could not insert hardware breakpoints:^M
You may have requested too many hardware breakpoints/watchpoints.^M
^M
(gdb) FAIL: gdb.base/watchpoint-reuse-slot.exp: always-inserted on: watch x hbreak: : width 1, iter 0: base + 1: hbreak *(buf.byte + 0 + 1)
This patch is to skip some tests by checking proc valid_addr_p.
We can handle other targets in valid_addr_p too.
gdb/testsuite:
2015-03-16 Yao Qi <yao.qi@linaro.org>
* gdb.base/watchpoint-reuse-slot.exp (valid_addr_p): New proc.
(top level): Skip tests if valid_addr_p returns false for
$cmd1 or $cmd2.
The test case "watchpoint-reuse-slot.exp" yields a lot of failures on
s390/s390x: all instances of awatch, rwatch, and hbreak are performed
even though they aren't supported on these targets. This is because
the test case ignores non-support error messages when probing for
support of these commands, like:
(gdb) rwatch buf.byte[0]
Target does not support this type of hardware watchpoint.
The patch adds handling for this case in the appropriate
gdb_test_multiple invocations.
gdb/testsuite/
* gdb.base/watchpoint-reuse-slot.exp: Handle the case that the
target lacks support for awatch, rwatch, or hbreak.
This patch fixes this on x86 Linux:
(gdb) watch *buf@2
Hardware watchpoint 8: *buf@2
(gdb) si
0x00000000004005a7 34 for (i = 0; i < 100000; i++); /* stepi line */
(gdb) del
Delete all breakpoints? (y or n) y
(gdb) watch *(buf+1)@1
Hardware watchpoint 9: *(buf+1)@1
(gdb) si
0x00000000004005a7 in main () at ../../../src/gdb/testsuite/gdb.base/watchpoint-reuse-slot.c:34
34 for (i = 0; i < 100000; i++); /* stepi line */
Couldn't write debug register: Invalid argument.
(gdb)
In the example above the debug registers are being switched from this
state:
CONTROL (DR7): 0000000000050101 STATUS (DR6): 0000000000000000
DR0: addr=0x0000000000601040, ref.count=1 DR1: addr=0x0000000000000000, ref.count=0
DR2: addr=0x0000000000000000, ref.count=0 DR3: addr=0x0000000000000000, ref.count=0
to this:
CONTROL (DR7): 0000000000010101 STATUS (DR6): 0000000000000000
DR0: addr=0x0000000000601041, ref.count=1 DR1: addr=0x0000000000000000, ref.count=0
DR2: addr=0x0000000000000000, ref.count=0 DR3: addr=0x0000000000000000, ref.count=0
That is, before, DR7 was setup for watching a 2 byte region starting
at what's in DR0 (0x601040).
And after, DR7 is setup for watching a 1 byte region starting at
what's in DR0 (0x601041).
We always write DR0..DR3 before DR7, because if we enable a slot's
bits in DR7, you need to have already written the corresponding
DR0..DR3 registers -- the kernel rejects the DR7 write with EINVAL
otherwise.
The error shown above is the opposite scenario. When we try to write
0x601041 to DR0, DR7's bits still indicate intent of watching a 2-byte
region. That DR0/DR7 combination is invalid, because 0x601041 is
unaligned. To watch two bytes, we'd have to use two slots. So the
kernel errors out with EINVAL.
Fix this by always first clearing DR7, then writing DR0..DR3, and then
setting DR7's bits.
A little optimization -- if we're disabling the last watchpoint, then
we can clear DR7 just once. The changes to nat/i386-dregs.c make that
easier to detect, and as bonus, they make it a little easier to make
sense of DR7 in the debug logs, as we no longer need to remember we're
seeing stale bits.
Tested on x86_64 Fedora 20, native and GDBserver.
This adds an exhaustive test that switches between many different
combinations of watchpoint types and addresses and widths.
gdb/
2014-06-23 Pedro Alves <palves@redhat.com>
* amd64-linux-nat.c (amd64_linux_prepare_to_resume): Clear
DR_CONTROL before setting DR0..DR3.
* i386-linux-nat.c (i386_linux_prepare_to_resume): Likewise.
* nat/i386-dregs.c (i386_remove_aligned_watchpoint): Clear all
bits of DR_CONTROL related to the debug register slot being
disabled. If all slots are vacant, clear local slowdown as well,
and assert DR_CONTROL is 0.
gdb/gdbserver/
2014-06-23 Pedro Alves <palves@redhat.com>
* linux-x86-low.c (x86_linux_prepare_to_resume): Clear DR_CONTROL
before setting DR0..DR3.
gdb/testsuite/
2014-06-23 Pedro Alves <palves@redhat.com>
* gdb.base/watchpoint-reuse-slot.c: New file.
* gdb.base/watchpoint-reuse-slot.exp: New file.
Andrew Burgess
Joel Brobecker
Luis Machado
Yao Qi
Andreas Arnez
Pedro Alves