[PATCH net-next 3/5] net: ipa: fix register write command validation
From: Alex Elder <hidden>
Date: 2021-02-10 22:35:40
Also in:
lkml
Subsystem:
networking drivers, qcom ipa driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Alex Elder, Linus Torvalds
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 <redacted>
---
drivers/net/ipa/ipa_cmd.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ipa/ipa_cmd.c b/drivers/net/ipa/ipa_cmd.c
index 97b50fee60089..8c832bf2637ab 100644
--- a/drivers/net/ipa/ipa_cmd.c
+++ b/drivers/net/ipa/ipa_cmd.c@@ -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;
--
2.20.1