Hi!
On 2023-06-30T01:39:39+0000, "Li, Pan2" <pan2...@intel.com> wrote:
> That’s very cool, thanks Thomas for help!
:-)
> Let’s wait the AMD test running result for the final version of the patch.
That's all looking good, too.
> From: juzhe.zh...@rivai.ai <juzhe.zh...@rivai.ai>
> Sent: Friday, June 30, 2023 9:27 AM
> Could you merge your patch after you tested?
I've done that, and with (already approved)
<https://inbox.sourceware.org/87v8f5uzob....@euler.schwinge.homeip.net>
"LTO: Capture 'lto_file_decl_data *file_data' in 'class lto_input_block'"
split out, OK to push the attached
v4 "Streamer: Fix out of range memory access of machine mode"?
Grüße
Thomas
> From: Thomas Schwinge<mailto:tho...@codesourcery.com>
> Date: 2023-06-30 04:14
> Subject: Re: [PATCH v3] Streamer: Fix out of range memory access of machine
> mode
> Hi!
>
> On 2023-06-29T11:29:57+0200, I wrote:
>> On 2023-06-21T15:58:24+0800, Pan Li via Gcc-patches
>> <gcc-patches@gcc.gnu.org<mailto:gcc-patches@gcc.gnu.org>> wrote:
>>> We extend the machine mode from 8 to 16 bits already. But there still
>>> one placing missing from the streamer. It has one hard coded array
>>> for the machine code like size 256.
>>>
>>> In the lto pass, we memset the array by MAX_MACHINE_MODE count but the
>>> value of the MAX_MACHINE_MODE will grow as more and more modes are
>>> added. While the machine mode array in tree-streamer still leave 256 as is.
>>>
>>> Then, when the MAX_MACHINE_MODE is greater than 256, the memset of
>>> lto_output_init_mode_table will touch the memory out of range unexpected.
>>
>> Uh. :-O
>>
>>> This patch would like to take the MAX_MACHINE_MODE as the size of the
>>> array in streamer, to make sure there is no potential unexpected
>>> memory access in future. Meanwhile, this patch also adjust some place
>>> which has MAX_MACHINE_MODE <= 256 assumption.
>>
>> Thanks to Jakub and Richard for guidance re the offloading compilation
>> case, where we've got different 'MAX_MACHINE_MODE's between stream-out
>> and stream-in, and a modes mapping table.
>>
>> However, with this patch, there are ICEs all over the place... I'm
>> having a look.
>
> Your patch has all the right ideas, there are just a few additional
> changes necessary. Please merge in the attached
> "f into Streamer: Fix out of range memory access of machine mode", with
> 'Co-authored-by: Thomas Schwinge
> <tho...@codesourcery.com<mailto:tho...@codesourcery.com>>'. This has
> already survived compiler-side 'lto.exp' testing and
> 'check-target-libgomp' with Nvidia GPU offloading; AMD GPU testing is now
> running (not expecting any bad surprises). Will let you know by (my)
> tomorrow morning in case there are any more problems.
>
> Explanation:
>
>>> --- a/gcc/lto-streamer-in.cc
>>> +++ b/gcc/lto-streamer-in.cc
>>> @@ -1985,8 +1985,6 @@ lto_input_mode_table (struct lto_file_decl_data
>>> *file_data)
>>> internal_error ("cannot read LTO mode table from %s",
>>> file_data->file_name);
>>>
>>> - unsigned char *table = ggc_cleared_vec_alloc<unsigned char> (1 << 8);
>>> - file_data->mode_table = table;
>>> const struct lto_simple_header_with_strings *header
>>> = (const struct lto_simple_header_with_strings *) data;
>>> int string_offset;
>>> @@ -1998,16 +1996,22 @@ lto_input_mode_table (struct lto_file_decl_data
>>> *file_data)
>>> header->string_size, vNULL);
>>> bitpack_d bp = streamer_read_bitpack (&ib);
>>>
>>> + unsigned mode_bits = bp_unpack_value (&bp, 5);
>>> + unsigned char *table = ggc_cleared_vec_alloc<unsigned char> (1 <<
>>> mode_bits);
>>> +
>>> + file_data->mode_table = table;
>>> + file_data->mode_bits = mode_bits;
>
> Here, we set 'file_data->mode_bits' for the offloading case (where
> 'lto_input_mode_table' is called) -- but it's not set for the
> non-offloading case (where 'lto_input_mode_table' isn't called). (See my
> 'gcc/lto/lto-common.cc:lto_read_decls' change.) That's "not currently a
> problem", as 'file_data->mode_bits' isn't used anywhere...
>
>>> --- a/gcc/lto-streamer.h
>>> +++ b/gcc/lto-streamer.h
>>> @@ -604,6 +604,8 @@ struct GTY(()) lto_file_decl_data
>>> int order_base;
>>>
>>> int unit_base;
>>> +
>>> + unsigned mode_bits;
>>> };
>
>>> inline machine_mode
>>> bp_unpack_machine_mode (struct bitpack_d *bp)
>>> {
>>> - return (machine_mode)
>>> - ((class lto_input_block *)
>>> - bp->stream)->mode_table[bp_unpack_enum (bp, machine_mode, 1 <<
>>> 8)];
>>> + int last = 1 << ceil_log2 (MAX_MACHINE_MODE);
>>> + lto_input_block *input_block = (class lto_input_block *) bp->stream;
>>> + int index = bp_unpack_enum (bp, machine_mode, last);
>>> +
>>> + return (machine_mode) input_block->mode_table[index];
>>> }
>
> ..., but 'file_data->mode_bits' needs to be considered here, in the
> stream-in for offloading, where 'file_data->mode_bits' -- that is, the
> host 'MAX_MACHINE_MODE' -- very likely is different from the offload
> device 'MAX_MACHINE_MODE'.
>
> Easiest is in 'gcc/lto-streamer.h:class lto_input_block' to capture
> 'lto_file_decl_data *file_data' instead of just
> 'unsigned char *mode_table', and adjust all users.
>
> That's it. :-)
>
>>> --- a/gcc/tree-streamer.h
>>> +++ b/gcc/tree-streamer.h
>
>>> @@ -108,15 +108,19 @@ inline void
>>> bp_pack_machine_mode (struct bitpack_d *bp, machine_mode mode)
>>> {
>>> streamer_mode_table[mode] = 1;
>>> - bp_pack_enum (bp, machine_mode, 1 << 8, mode);
>>> + int last = 1 << ceil_log2 (MAX_MACHINE_MODE);
>>> +
>>> + bp_pack_enum (bp, machine_mode, last, mode);
>>> }
>
> That use of 'MAX_MACHINE_MODE' is safe, as that only concerns the
> stream-out phase.
>
>>> --- a/gcc/tree-streamer.cc
>>> +++ b/gcc/tree-streamer.cc
>>> @@ -35,7 +35,7 @@ along with GCC; see the file COPYING3. If not see
>>> During streaming in, we translate the on the disk mode using this
>>> table. For normal LTO it is set to identity, for ACCEL_COMPILER
>>> depending on the mode_table content. */
>>> -unsigned char streamer_mode_table[1 << 8];
>>> +unsigned char streamer_mode_table[MAX_MACHINE_MODE];
>
> Likewise.
>
>
> Grüße
> Thomas
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>From f61d1ffbf0d1e1aa65dcb96e9b32b4e2fca7ed69 Mon Sep 17 00:00:00 2001
From: Pan Li <pan2...@intel.com>
Date: Wed, 21 Jun 2023 15:58:24 +0800
Subject: [PATCH] Streamer: Fix out of range memory access of machine mode
We extend the machine mode from 8 to 16 bits already. But there still
one placing missing from the streamer. It has one hard coded array
for the machine code like size 256.
In the lto pass, we memset the array by MAX_MACHINE_MODE count but the
value of the MAX_MACHINE_MODE will grow as more and more modes are
added. While the machine mode array in tree-streamer still leave 256 as is.
Then, when the MAX_MACHINE_MODE is greater than 256, the memset of
lto_output_init_mode_table will touch the memory out of range unexpected.
This patch would like to take the MAX_MACHINE_MODE as the size of the
array in streamer, to make sure there is no potential unexpected
memory access in future. Meanwhile, this patch also adjust some place
which has MAX_MACHINE_MODE <= 256 assumption.
Care is taken that for offload compilation, we interpret the stream-in
data in terms of the host 'MAX_MACHINE_MODE' ('file_data->mode_bits'),
which very likely is different from the offload device
'MAX_MACHINE_MODE'.
gcc/
* lto-streamer-in.cc (lto_input_mode_table): Stream in the mode
bits for machine mode table.
* lto-streamer-out.cc (lto_write_mode_table): Stream out the
HOST machine mode bits.
* lto-streamer.h (struct lto_file_decl_data): New fields mode_bits.
* tree-streamer.cc (streamer_mode_table): Take MAX_MACHINE_MODE
as the table size.
* tree-streamer.h (streamer_mode_table): Ditto.
(bp_pack_machine_mode): Take 1 << ceil_log2 (MAX_MACHINE_MODE)
as the packing limit.
(bp_unpack_machine_mode): Ditto with 'file_data->mode_bits'.
gcc/lto/
* lto-common.cc (lto_file_finalize) [!ACCEL_COMPILER]: Initialize
'file_data->mode_bits'.
Signed-off-by: Pan Li <pan2...@intel.com>
Co-authored-by: Thomas Schwinge <tho...@codesourcery.com>
---
gcc/lto-streamer-in.cc | 12 ++++++++----
gcc/lto-streamer-out.cc | 11 ++++++++---
gcc/lto-streamer.h | 2 ++
gcc/lto/lto-common.cc | 1 +
gcc/tree-streamer.cc | 2 +-
gcc/tree-streamer.h | 8 +++++---
6 files changed, 25 insertions(+), 11 deletions(-)
diff --git a/gcc/lto-streamer-in.cc b/gcc/lto-streamer-in.cc
index 6e8bc9516a6..1876e1967ec 100644
--- a/gcc/lto-streamer-in.cc
+++ b/gcc/lto-streamer-in.cc
@@ -1985,8 +1985,6 @@ lto_input_mode_table (struct lto_file_decl_data *file_data)
internal_error ("cannot read LTO mode table from %s",
file_data->file_name);
- unsigned char *table = ggc_cleared_vec_alloc<unsigned char> (1 << 8);
- file_data->mode_table = table;
const struct lto_simple_header_with_strings *header
= (const struct lto_simple_header_with_strings *) data;
int string_offset;
@@ -1998,16 +1996,22 @@ lto_input_mode_table (struct lto_file_decl_data *file_data)
header->string_size, vNULL);
bitpack_d bp = streamer_read_bitpack (&ib);
+ unsigned mode_bits = bp_unpack_value (&bp, 5);
+ unsigned char *table = ggc_cleared_vec_alloc<unsigned char> (1 << mode_bits);
+
+ file_data->mode_table = table;
+ file_data->mode_bits = mode_bits;
+
table[VOIDmode] = VOIDmode;
table[BLKmode] = BLKmode;
unsigned int m;
- while ((m = bp_unpack_value (&bp, 8)) != VOIDmode)
+ while ((m = bp_unpack_value (&bp, mode_bits)) != VOIDmode)
{
enum mode_class mclass
= bp_unpack_enum (&bp, mode_class, MAX_MODE_CLASS);
poly_uint16 size = bp_unpack_poly_value (&bp, 16);
poly_uint16 prec = bp_unpack_poly_value (&bp, 16);
- machine_mode inner = (machine_mode) bp_unpack_value (&bp, 8);
+ machine_mode inner = (machine_mode) bp_unpack_value (&bp, mode_bits);
poly_uint16 nunits = bp_unpack_poly_value (&bp, 16);
unsigned int ibit = 0, fbit = 0;
unsigned int real_fmt_len = 0;
diff --git a/gcc/lto-streamer-out.cc b/gcc/lto-streamer-out.cc
index 5ab2eb4301e..36899283ded 100644
--- a/gcc/lto-streamer-out.cc
+++ b/gcc/lto-streamer-out.cc
@@ -3196,6 +3196,11 @@ lto_write_mode_table (void)
if (inner_m != m)
streamer_mode_table[(int) inner_m] = 1;
}
+
+ /* Pack the mode_bits value within 5 bits (up to 31) in the beginning. */
+ unsigned mode_bits = ceil_log2 (MAX_MACHINE_MODE);
+ bp_pack_value (&bp, mode_bits, 5);
+
/* First stream modes that have GET_MODE_INNER (m) == m,
so that we can refer to them afterwards. */
for (int pass = 0; pass < 2; pass++)
@@ -3205,11 +3210,11 @@ lto_write_mode_table (void)
machine_mode m = (machine_mode) i;
if ((GET_MODE_INNER (m) == m) ^ (pass == 0))
continue;
- bp_pack_value (&bp, m, 8);
+ bp_pack_value (&bp, m, mode_bits);
bp_pack_enum (&bp, mode_class, MAX_MODE_CLASS, GET_MODE_CLASS (m));
bp_pack_poly_value (&bp, GET_MODE_SIZE (m), 16);
bp_pack_poly_value (&bp, GET_MODE_PRECISION (m), 16);
- bp_pack_value (&bp, GET_MODE_INNER (m), 8);
+ bp_pack_value (&bp, GET_MODE_INNER (m), mode_bits);
bp_pack_poly_value (&bp, GET_MODE_NUNITS (m), 16);
switch (GET_MODE_CLASS (m))
{
@@ -3229,7 +3234,7 @@ lto_write_mode_table (void)
}
bp_pack_string (ob, &bp, GET_MODE_NAME (m), true);
}
- bp_pack_value (&bp, VOIDmode, 8);
+ bp_pack_value (&bp, VOIDmode, mode_bits);
streamer_write_bitpack (&bp);
diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h
index 2913b808bde..0556b34c837 100644
--- a/gcc/lto-streamer.h
+++ b/gcc/lto-streamer.h
@@ -604,6 +604,8 @@ struct GTY(()) lto_file_decl_data
int order_base;
int unit_base;
+
+ unsigned mode_bits;
};
typedef struct lto_file_decl_data *lto_file_decl_data_ptr;
diff --git a/gcc/lto/lto-common.cc b/gcc/lto/lto-common.cc
index c235df8a5f5..973ab791712 100644
--- a/gcc/lto/lto-common.cc
+++ b/gcc/lto/lto-common.cc
@@ -2275,6 +2275,7 @@ lto_file_finalize (struct lto_file_decl_data *file_data, lto_file *file,
lto_input_mode_table (file_data);
#else
file_data->mode_table = lto_mode_identity_table;
+ file_data->mode_bits = ceil_log2 (MAX_MACHINE_MODE);
#endif
data = lto_get_summary_section_data (file_data, LTO_section_decls, &len);
diff --git a/gcc/tree-streamer.cc b/gcc/tree-streamer.cc
index ed65a7692e3..a28ef9c7920 100644
--- a/gcc/tree-streamer.cc
+++ b/gcc/tree-streamer.cc
@@ -35,7 +35,7 @@ along with GCC; see the file COPYING3. If not see
During streaming in, we translate the on the disk mode using this
table. For normal LTO it is set to identity, for ACCEL_COMPILER
depending on the mode_table content. */
-unsigned char streamer_mode_table[1 << 8];
+unsigned char streamer_mode_table[MAX_MACHINE_MODE];
/* Check that all the TS_* structures handled by the streamer_write_* and
streamer_read_* routines are exactly ALL the structures defined in
diff --git a/gcc/tree-streamer.h b/gcc/tree-streamer.h
index 6d565acbbc2..ff49d1ba637 100644
--- a/gcc/tree-streamer.h
+++ b/gcc/tree-streamer.h
@@ -75,7 +75,7 @@ void streamer_write_tree_body (struct output_block *, tree);
void streamer_write_integer_cst (struct output_block *, tree);
/* In tree-streamer.cc. */
-extern unsigned char streamer_mode_table[1 << 8];
+extern unsigned char streamer_mode_table[MAX_MACHINE_MODE];
void streamer_check_handled_ts_structures (void);
bool streamer_tree_cache_insert (struct streamer_tree_cache_d *, tree,
hashval_t, unsigned *);
@@ -108,14 +108,16 @@ inline void
bp_pack_machine_mode (struct bitpack_d *bp, machine_mode mode)
{
streamer_mode_table[mode] = 1;
- bp_pack_enum (bp, machine_mode, 1 << 8, mode);
+ int last = 1 << ceil_log2 (MAX_MACHINE_MODE);
+ bp_pack_enum (bp, machine_mode, last, mode);
}
inline machine_mode
bp_unpack_machine_mode (struct bitpack_d *bp)
{
lto_input_block *ib = (class lto_input_block *) bp->stream;
- unsigned ix = bp_unpack_enum (bp, machine_mode, 1 << 8);
+ int last = 1 << ib->file_data->mode_bits;
+ unsigned ix = bp_unpack_enum (bp, machine_mode, last);
return (machine_mode) ib->file_data->mode_table[ix];
}
--
2.34.1
