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| author | Par Olsson <par.olsson@windriver.com> | 2016-04-28 12:54:07 -0400 |
|---|---|---|
| committer | Simon Marchi <simon.marchi@ericsson.com> | 2016-04-28 12:56:05 -0400 |
| commit | 35fd2deb6916e972248d52b1bc1d584fa9059f8f (patch) | |
| tree | 30a626e989c31b451a639d012a795a9f68f42b1c /gdb/gdbserver | |
| parent | 952ebca5831911a8ef2a79f6e1e7a2c24f71a388 (diff) | |
| download | gdb-35fd2deb6916e972248d52b1bc1d584fa9059f8f.zip gdb-35fd2deb6916e972248d52b1bc1d584fa9059f8f.tar.gz gdb-35fd2deb6916e972248d52b1bc1d584fa9059f8f.tar.bz2 | |
Fix write endianness/size problem for fast tracepoint enabled flag
I am sending this fix on behalf of Par Olsson, as a follow-up of this
one:
https://www.sourceware.org/ml/gdb-patches/2015-10/msg00196.html
This problem is exposed when enabling/disabling fast tracepoints on big
endian machines. The flag is defined as an int8_t, but is written from
gdbserver as an integer (usually 32 bits). When the agent code reads it
as an int8_t, it only considers the most significant byte, which is
always 0.
Also, we were writing 32 bits in an 8 bits field, so the write would
overflow, but since the following bytes are padding (the next field is
an uint64_t), it luckily didn't cause any issue on little endian
systems.
The fix was originally tested on ARM big endian systems, but I don't
have access to such a system. However, thanks to Marcin's PowerPC fast
tracepoint patches and gcc110 (big endian Power7) on the gcc compile
farm, I was able to reproduce the problem, test the fix and write a
test (the following patch).
gdb/gdbserver/ChangeLog:
YYYY-MM-DD Par Olsson <par.olsson@windriver.com>
* tracepoint.c (write_inferior_int8): New function.
(cmd_qtenable_disable): Write enable flag using
write_inferior_int8.
Diffstat (limited to 'gdb/gdbserver')
| -rw-r--r-- | gdb/gdbserver/ChangeLog | 7 | ||||
| -rw-r--r-- | gdb/gdbserver/tracepoint.c | 8 |
2 files changed, 14 insertions, 1 deletions
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index c9b1e9d..a0c90ee 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,10 @@ +2016-04-28 Par Olsson <par.olsson@windriver.com> +2016-04-28 Simon Marchi <simon.marchi@ericsson.com> + + * tracepoint.c (write_inferior_int8): New function. + (cmd_qtenable_disable): Write enable flag using + write_inferior_int8. + 2016-04-25 Yao Qi <yao.qi@linaro.org> * linux-low.c (lwp_signal_can_be_delivered): Adjust. diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c index 620b94f..c07e525 100644 --- a/gdb/gdbserver/tracepoint.c +++ b/gdb/gdbserver/tracepoint.c @@ -449,6 +449,12 @@ write_inferior_integer (CORE_ADDR symaddr, int val) } static int +write_inferior_int8 (CORE_ADDR symaddr, int8_t val) +{ + return write_inferior_memory (symaddr, (unsigned char *) &val, sizeof (val)); +} + +static int write_inferior_uinteger (CORE_ADDR symaddr, unsigned int val) { return write_inferior_memory (symaddr, (unsigned char *) &val, sizeof (val)); @@ -2784,7 +2790,7 @@ cmd_qtenable_disable (char *own_buf, int enable) return; } - ret = write_inferior_integer (obj_addr, enable); + ret = write_inferior_int8 (obj_addr, enable); done_accessing_memory (); if (ret) |