Hi Alan,
The patch LGTM. I noted two small comments you might want to address before
pushing. Sorry again for the extra work I made you do!
On 2018-06-22 09:08 AM, Alan Hayward wrote:
> @@ -868,6 +900,39 @@ regcache::write_part (int regnum, int offset, int len,
>
> /* See regcache.h. */
>
> +void
> +reg_buffer::raw_supply_part (int regnum, int offset, int len,
> + const gdb_byte *in)
> +{
> + int reg_size = register_size (arch (), regnum);
> +
> + gdb_assert (in != nullptr);
> + gdb_assert (offset >= 0 && offset <= reg_size);
> + gdb_assert (len >= 0 && offset + len <= reg_size);
> +
> + if (offset == 0 && len == 0)
> + {
> + /* Nothing to do. */
> + return;
> + }
> +
> + if (offset == 0 && len == reg_size)
> + {
> + /* Supply the full register. */
> + return raw_supply (regnum, in);
> + }
> +
> + gdb_byte *reg = (gdb_byte *) alloca (reg_size);
> +
> + /* Read when needed. */
> + if (offset > 0 || offset + len < reg_size)
I think this if is unneeded now, with the earlier check? If we reach
this point, it will always be for a partial register.
> diff --git a/gdb/regcache.h b/gdb/regcache.h
> index 983137f6ad..e706d87b54 100644
> --- a/gdb/regcache.h
> +++ b/gdb/regcache.h
> @@ -166,6 +166,10 @@ public:
> void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
> bool is_signed) const;
>
> + /* Collect register REGNUM from REGCACHE, starting at offset in REGCACHE,
> + reading only LEN. */
I think "starting at offset in REGCACHE" is wrong, you probably meant
"starting at offset in the register" or something like that?
> + void raw_collect_part (int regnum, int offset, int len, gdb_byte *out) const;
> +
> /* See common/common-regcache.h. */
> void raw_supply (int regnum, const void *buf) override;
>
> @@ -187,6 +191,10 @@ public:
> unavailable). */
> void raw_supply_zeroed (int regnum);
>
> + /* Supply register REGNUM to REGCACHE, starting at offset in REGCACHE, writing
> + only LEN, without editing the rest of the register. */
Here too.
Thanks,
Simon
> On 22 Jun 2018, at 15:25, Simon Marchi <simon.marchi@ericsson.com> wrote:
>
> Hi Alan,
>
> The patch LGTM. I noted two small comments you might want to address before
> pushing. Sorry again for the extra work I made you do!
No probs!
>
> On 2018-06-22 09:08 AM, Alan Hayward wrote:
>> @@ -868,6 +900,39 @@ regcache::write_part (int regnum, int offset, int len,
>>
>> /* See regcache.h. */
>>
>> +void
>> +reg_buffer::raw_supply_part (int regnum, int offset, int len,
>> + const gdb_byte *in)
>> +{
>> + int reg_size = register_size (arch (), regnum);
>> +
>> + gdb_assert (in != nullptr);
>> + gdb_assert (offset >= 0 && offset <= reg_size);
>> + gdb_assert (len >= 0 && offset + len <= reg_size);
>> +
>> + if (offset == 0 && len == 0)
>> + {
>> + /* Nothing to do. */
>> + return;
>> + }
>> +
>> + if (offset == 0 && len == reg_size)
>> + {
>> + /* Supply the full register. */
>> + return raw_supply (regnum, in);
>> + }
>> +
>> + gdb_byte *reg = (gdb_byte *) alloca (reg_size);
>> +
>> + /* Read when needed. */
>> + if (offset > 0 || offset + len < reg_size)
>
> I think this if is unneeded now, with the earlier check? If we reach
> this point, it will always be for a partial register.
Yes. I had removed the same check from raw_collect_part, but didn’t
spot this.
>
>> diff --git a/gdb/regcache.h b/gdb/regcache.h
>> index 983137f6ad..e706d87b54 100644
>> --- a/gdb/regcache.h
>> +++ b/gdb/regcache.h
>> @@ -166,6 +166,10 @@ public:
>> void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
>> bool is_signed) const;
>>
>> + /* Collect register REGNUM from REGCACHE, starting at offset in REGCACHE,
>> + reading only LEN. */
>
> I think "starting at offset in REGCACHE" is wrong, you probably meant
> "starting at offset in the register" or something like that?
Done.
>
>> + void raw_collect_part (int regnum, int offset, int len, gdb_byte *out) const;
>> +
>> /* See common/common-regcache.h. */
>> void raw_supply (int regnum, const void *buf) override;
>>
>> @@ -187,6 +191,10 @@ public:
>> unavailable). */
>> void raw_supply_zeroed (int regnum);
>>
>> + /* Supply register REGNUM to REGCACHE, starting at offset in REGCACHE, writing
>> + only LEN, without editing the rest of the register. */
>
> Here too.
>
Done.
Pushed with changes as suggested.
Thanks,
Alan.
@@ -801,7 +801,8 @@ readable_regcache::read_part (int regnum, int offset, int len,
int reg_size = register_size (arch (), regnum);
gdb_assert (out != NULL);
- gdb_assert (offset >= 0 && len >= 0 && offset + len <= reg_size);
+ gdb_assert (offset >= 0 && offset <= reg_size);
+ gdb_assert (len >= 0 && offset + len <= reg_size);
if (offset == 0 && len == 0)
{
@@ -830,6 +831,36 @@ readable_regcache::read_part (int regnum, int offset, int len,
/* See regcache.h. */
+void
+reg_buffer::raw_collect_part (int regnum, int offset, int len,
+ gdb_byte *out) const
+{
+ int reg_size = register_size (arch (), regnum);
+
+ gdb_assert (out != nullptr);
+ gdb_assert (offset >= 0 && offset <= reg_size);
+ gdb_assert (len >= 0 && offset + len <= reg_size);
+
+ if (offset == 0 && len == 0)
+ {
+ /* Nothing to do. */
+ return;
+ }
+
+ if (offset == 0 && len == reg_size)
+ {
+ /* Collect the full register. */
+ return raw_collect (regnum, out);
+ }
+
+ /* Read to buffer, then write out. */
+ gdb_byte *reg = (gdb_byte *) alloca (reg_size);
+ raw_collect (regnum, reg);
+ memcpy (out, reg + offset, len);
+}
+
+/* See regcache.h. */
+
enum register_status
regcache::write_part (int regnum, int offset, int len,
const gdb_byte *in, bool is_raw)
@@ -837,7 +868,8 @@ regcache::write_part (int regnum, int offset, int len,
int reg_size = register_size (arch (), regnum);
gdb_assert (in != NULL);
- gdb_assert (offset >= 0 && len >= 0 && offset + len <= reg_size);
+ gdb_assert (offset >= 0 && offset <= reg_size);
+ gdb_assert (len >= 0 && offset + len <= reg_size);
if (offset == 0 && len == 0)
{
@@ -868,6 +900,39 @@ regcache::write_part (int regnum, int offset, int len,
/* See regcache.h. */
+void
+reg_buffer::raw_supply_part (int regnum, int offset, int len,
+ const gdb_byte *in)
+{
+ int reg_size = register_size (arch (), regnum);
+
+ gdb_assert (in != nullptr);
+ gdb_assert (offset >= 0 && offset <= reg_size);
+ gdb_assert (len >= 0 && offset + len <= reg_size);
+
+ if (offset == 0 && len == 0)
+ {
+ /* Nothing to do. */
+ return;
+ }
+
+ if (offset == 0 && len == reg_size)
+ {
+ /* Supply the full register. */
+ return raw_supply (regnum, in);
+ }
+
+ gdb_byte *reg = (gdb_byte *) alloca (reg_size);
+
+ /* Read when needed. */
+ if (offset > 0 || offset + len < reg_size)
+ raw_collect (regnum, reg);
+
+ /* Write to buffer, then write out. */
+ memcpy (reg + offset, in, len);
+ raw_supply (regnum, reg);
+}
+
enum register_status
readable_regcache::raw_read_part (int regnum, int offset, int len,
gdb_byte *buf)
@@ -1006,15 +1071,43 @@ reg_buffer::raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
byte_order);
}
-/* Transfer a single or all registers belonging to a certain register
- set to or from a buffer. This is the main worker function for
- regcache_supply_regset and regcache_collect_regset. */
+/* See regcache.h. */
+
+void
+regcache::transfer_regset_register (struct regcache *out_regcache, int regnum,
+ const gdb_byte *in_buf, gdb_byte *out_buf,
+ int slot_size, int offs) const
+{
+ struct gdbarch *gdbarch = arch ();
+ int reg_size = std::min (register_size (gdbarch, regnum), slot_size);
+
+ /* Use part versions and reg_size to prevent possible buffer overflows when
+ accessing the regcache. */
+
+ if (out_buf != nullptr)
+ {
+ raw_collect_part (regnum, 0, reg_size, out_buf + offs);
+
+ /* Ensure any additional space is cleared. */
+ if (slot_size > reg_size)
+ memset (out_buf + offs + reg_size, 0, slot_size - reg_size);
+ }
+ else if (in_buf != nullptr)
+ out_regcache->raw_supply_part (regnum, 0, reg_size, in_buf + offs);
+ else
+ {
+ /* Invalidate the register. */
+ out_regcache->raw_supply (regnum, nullptr);
+ }
+}
+
+/* See regcache.h. */
void
regcache::transfer_regset (const struct regset *regset,
struct regcache *out_regcache,
- int regnum, const void *in_buf,
- void *out_buf, size_t size) const
+ int regnum, const gdb_byte *in_buf,
+ gdb_byte *out_buf, size_t size) const
{
const struct regcache_map_entry *map;
int offs = 0, count;
@@ -1040,12 +1133,8 @@ regcache::transfer_regset (const struct regset *regset,
if (offs + slot_size > size)
break;
- if (out_buf)
- raw_collect (regno, (gdb_byte *) out_buf + offs);
- else
- out_regcache->raw_supply (regno, in_buf
- ? (const gdb_byte *) in_buf + offs
- : NULL);
+ transfer_regset_register (out_regcache, regno, in_buf, out_buf,
+ slot_size, offs);
}
else
{
@@ -1054,12 +1143,8 @@ regcache::transfer_regset (const struct regset *regset,
if (offs + slot_size > size)
return;
- if (out_buf)
- raw_collect (regnum, (gdb_byte *) out_buf + offs);
- else
- out_regcache->raw_supply (regnum, in_buf
- ? (const gdb_byte *) in_buf + offs
- : NULL);
+ transfer_regset_register (out_regcache, regnum, in_buf, out_buf,
+ slot_size, offs);
return;
}
}
@@ -1074,14 +1159,14 @@ regcache_supply_regset (const struct regset *regset,
struct regcache *regcache,
int regnum, const void *buf, size_t size)
{
- regcache->supply_regset (regset, regnum, buf, size);
+ regcache->supply_regset (regset, regnum, (const gdb_byte *) buf, size);
}
void
regcache::supply_regset (const struct regset *regset,
int regnum, const void *buf, size_t size)
{
- transfer_regset (regset, this, regnum, buf, NULL, size);
+ transfer_regset (regset, this, regnum, (const gdb_byte *) buf, nullptr, size);
}
/* Collect register REGNUM from REGCACHE to BUF, using the register
@@ -1093,14 +1178,14 @@ regcache_collect_regset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *buf, size_t size)
{
- regcache->collect_regset (regset, regnum, buf, size);
+ regcache->collect_regset (regset, regnum, (gdb_byte *) buf, size);
}
void
regcache::collect_regset (const struct regset *regset,
int regnum, void *buf, size_t size) const
{
- transfer_regset (regset, NULL, regnum, NULL, buf, size);
+ transfer_regset (regset, nullptr, regnum, nullptr, (gdb_byte *) buf, size);
}
/* See common/common-regcache.h. */
@@ -166,6 +166,10 @@ public:
void raw_collect_integer (int regnum, gdb_byte *addr, int addr_len,
bool is_signed) const;
+ /* Collect register REGNUM from REGCACHE, starting at offset in REGCACHE,
+ reading only LEN. */
+ void raw_collect_part (int regnum, int offset, int len, gdb_byte *out) const;
+
/* See common/common-regcache.h. */
void raw_supply (int regnum, const void *buf) override;
@@ -187,6 +191,10 @@ public:
unavailable). */
void raw_supply_zeroed (int regnum);
+ /* Supply register REGNUM to REGCACHE, starting at offset in REGCACHE, writing
+ only LEN, without editing the rest of the register. */
+ void raw_supply_part (int regnum, int offset, int len, const gdb_byte *in);
+
void invalidate (int regnum);
virtual ~reg_buffer () = default;
@@ -358,10 +366,18 @@ protected:
private:
+ /* Helper function for transfer_regset. Copies across a single register. */
+ void transfer_regset_register (struct regcache *out_regcache, int regnum,
+ const gdb_byte *in_buf, gdb_byte *out_buf,
+ int slot_size, int offs) const;
+
+ /* Transfer a single or all registers belonging to a certain register
+ set to or from a buffer. This is the main worker function for
+ regcache_supply_regset and regcache_collect_regset. */
void transfer_regset (const struct regset *regset,
struct regcache *out_regcache,
- int regnum, const void *in_buf,
- void *out_buf, size_t size) const;
+ int regnum, const gdb_byte *in_buf,
+ gdb_byte *out_buf, size_t size) const;
/* Perform a partial register transfer using a read, modify, write
operation. */