diff options
| -rw-r--r-- | gdb/ChangeLog | 8 | ||||
| -rw-r--r-- | gdb/riscv-tdep.c | 65 |
2 files changed, 67 insertions, 6 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 513bc7c..b078551 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,13 @@ 2018-12-22 Andrew Burgess <andrew.burgess@embecosm.com> + * riscv-tdep.c (riscv_call_arg_struct): Don't adjust size before + assigning locations. + (riscv_return_value): Take more care not to read/write outside of + argument buffer. Cast return value between the declared type and + the abi type. + +2018-12-22 Andrew Burgess <andrew.burgess@embecosm.com> + * riscv-tdep.c (riscv_register_reggroup_p): Save and restore fcsr, fflags, and frm registers. diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c index 704e851..ef3bb09 100644 --- a/gdb/riscv-tdep.c +++ b/gdb/riscv-tdep.c @@ -2199,7 +2199,6 @@ riscv_call_arg_struct (struct riscv_arg_info *ainfo, /* Non of the structure flattening cases apply, so we just pass using the integer ABI. */ - ainfo->length = align_up (ainfo->length, cinfo->xlen); riscv_call_arg_scalar_int (ainfo, cinfo); } @@ -2579,7 +2578,35 @@ riscv_return_value (struct gdbarch *gdbarch, if (readbuf != nullptr || writebuf != nullptr) { - int regnum; + unsigned int arg_len; + struct value *abi_val; + gdb_byte *old_readbuf = nullptr; + int regnum; + + /* We only do one thing at a time. */ + gdb_assert (readbuf == nullptr || writebuf == nullptr); + + /* In some cases the argument is not returned as the declared type, + and we need to cast to or from the ABI type in order to + correctly access the argument. When writing to the machine we + do the cast here, when reading from the machine the cast occurs + later, after extracting the value. As the ABI type can be + larger than the declared type, then the read or write buffers + passed in might be too small. Here we ensure that we are using + buffers of sufficient size. */ + if (writebuf != nullptr) + { + struct value *arg_val = value_from_contents (arg_type, writebuf); + abi_val = value_cast (info.type, arg_val); + writebuf = value_contents_raw (abi_val); + } + else + { + abi_val = allocate_value (info.type); + old_readbuf = readbuf; + readbuf = value_contents_raw (abi_val); + } + arg_len = TYPE_LENGTH (info.type); switch (info.argloc[0].loc_type) { @@ -2587,12 +2614,19 @@ riscv_return_value (struct gdbarch *gdbarch, case riscv_arg_info::location::in_reg: { regnum = info.argloc[0].loc_data.regno; + gdb_assert (info.argloc[0].c_length <= arg_len); + gdb_assert (info.argloc[0].c_length + <= register_size (gdbarch, regnum)); if (readbuf) - regcache->cooked_read (regnum, readbuf); + regcache->cooked_read_part (regnum, 0, + info.argloc[0].c_length, + readbuf); if (writebuf) - regcache->cooked_write (regnum, writebuf); + regcache->cooked_write_part (regnum, 0, + info.argloc[0].c_length, + writebuf); /* A return value in register can have a second part in a second register. */ @@ -2603,16 +2637,25 @@ riscv_return_value (struct gdbarch *gdbarch, case riscv_arg_info::location::in_reg: regnum = info.argloc[1].loc_data.regno; + gdb_assert ((info.argloc[0].c_length + + info.argloc[1].c_length) <= arg_len); + gdb_assert (info.argloc[1].c_length + <= register_size (gdbarch, regnum)); + if (readbuf) { readbuf += info.argloc[1].c_offset; - regcache->cooked_read (regnum, readbuf); + regcache->cooked_read_part (regnum, 0, + info.argloc[1].c_length, + readbuf); } if (writebuf) { writebuf += info.argloc[1].c_offset; - regcache->cooked_write (regnum, writebuf); + regcache->cooked_write_part (regnum, 0, + info.argloc[1].c_length, + writebuf); } break; @@ -2645,6 +2688,16 @@ riscv_return_value (struct gdbarch *gdbarch, error (_("invalid argument location")); break; } + + /* This completes the cast from abi type back to the declared type + in the case that we are reading from the machine. See the + comment at the head of this block for more details. */ + if (readbuf != nullptr) + { + struct value *arg_val = value_cast (arg_type, abi_val); + memcpy (old_readbuf, value_contents_raw (arg_val), + TYPE_LENGTH (arg_type)); + } } switch (info.argloc[0].loc_type) |