mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-08 05:43:28 -04:00
Code Issues Packages Projects Releases Wiki Activity

net: ipa: fix register write command validation

Browse Source 
In ipa_cmd_register_write_valid() we verify that values we will
supply to a REGISTER_WRITE IPA immediate command will fit in
the fields that need to hold them.  This patch fixes some issues
in that function and ipa_cmd_register_write_offset_valid().

The dev_err() call in ipa_cmd_register_write_offset_valid() has
some printf format errors:
  - The name of the register (corresponding to the string format
    specifier) was not supplied.
  - The IPA base offset and offset need to be supplied separately to
    match the other format specifiers.
Also make the ~0 constant used there to compute the maximum
supported offset value explicitly unsigned.

There are two other issues in ipa_cmd_register_write_valid():
  - There's no need to check the hash flush register for platforms
    (like IPA v4.2) that do not support hashed tables
  - The highest possible endpoint number, whose status register
    offset is computed, is COUNT - 1, not COUNT.

Fix these problems, and add some additional commentary.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alex Elder
2021-02-12 08:34:00 -06:00
committed by David S. Miller
parent 4c7ccfcd09
commit 2d65ed7692
1 changed files with 24 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/net/ipa/ipa_cmd.c
View File

@@ -1,7 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2019-2020 Linaro Ltd.
* Copyright (C) 2019-2021 Linaro Ltd.
*/
#include <linux/types.h>
@@ -244,11 +244,15 @@ static bool ipa_cmd_register_write_offset_valid(struct ipa *ipa,
if (ipa->version != IPA_VERSION_3_5_1)
bit_count += hweight32(REGISTER_WRITE_FLAGS_OFFSET_HIGH_FMASK);
BUILD_BUG_ON(bit_count > 32);
offset_max = ~0 >> (32 - bit_count);
offset_max = ~0U >> (32 - bit_count);
/* Make sure the offset can be represented by the field(s)
* that holds it. Also make sure the offset is not outside
* the overall IPA memory range.
*/
if (offset > offset_max || ipa->mem_offset > offset_max - offset) {
dev_err(dev, "%s offset too large 0x%04x + 0x%04x > 0x%04x)\n",
ipa->mem_offset + offset, offset_max);
name, ipa->mem_offset, offset, offset_max);
return false;
}
@@ -261,12 +265,24 @@ static bool ipa_cmd_register_write_valid(struct ipa *ipa)
const char *name;
u32 offset;
offset = ipa_reg_filt_rout_hash_flush_offset(ipa->version);
name = "filter/route hash flush";
if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
return false;
/* If hashed tables are supported, ensure the hash flush register
* offset will fit in a register write IPA immediate command.
*/
if (ipa->version != IPA_VERSION_4_2) {
offset = ipa_reg_filt_rout_hash_flush_offset(ipa->version);
name = "filter/route hash flush";
if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
return false;
}
offset = IPA_REG_ENDP_STATUS_N_OFFSET(IPA_ENDPOINT_COUNT);
/* Each endpoint can have a status endpoint associated with it,
* and this is recorded in an endpoint register. If the modem
* crashes, we reset the status endpoint for all modem endpoints
* using a register write IPA immediate command. Make sure the
* worst case (highest endpoint number) offset of that endpoint
* fits in the register write command field(s) that must hold it.
*/
offset = IPA_REG_ENDP_STATUS_N_OFFSET(IPA_ENDPOINT_COUNT - 1);
name = "maximal endpoint status";
if (!ipa_cmd_register_write_offset_valid(ipa, name, offset))
return false;