On 3/18/21 11:29 PM, Alex Elder wrote:
There is sanity checking code in the IPA driver that's meant to be enabled only during development. This allows the driver to make certain assumptions, but not have to verify those assumptions are true at (operational) runtime. This code is built conditional on IPA_VALIDATION, set (if desired) inside the IPA makefile.
Given the pushback on the ipa_assert() patch I will send out version 2 of this series, omitting the two patches that involve assertions. I still think there's a case for my proposal, but I'm going to move on for now and try to find other ways to do what I want. In some cases BUILD_BUG_ON() or WARN_ON_DEV() could be used. In other spots, I might be able to use dev_dbg() for checking things only while developing. But there remain a few cases where none of these options is quite right. If I ever want to suggest an assertion again I'll do it as an RFC and will copy Leon and Andrew, to make sure they can provide input. Thanks. -Alex
Unfortunately, this validation code has some errors. First, there are some mismatched arguments supplied to some dev_err() calls in ipa_cmd_table_valid() and ipa_cmd_header_valid(), and these are exposed if validation is enabled. Second, the tag that enables this conditional code isn't used consistently (it's IPA_VALIDATE in some spots and IPA_VALIDATION in others). This series fixes those two problems with the conditional validation code. In addition, this series introduces some new assertion macros. I have been meaning to add this for a long time. There are comments indicating places where assertions could be checked throughout the code. The macros are designed so that any asserted condition will be checked at compile time if possible. Otherwise, the condition will be checked at runtime *only* if IPA_VALIDATION is enabled, and ignored otherwise. NOTE: The third patch produces two bogus (but understandable) warnings from checkpatch.pl. It does not recognize that the "expr" argument passed to those macros aren't actually evaluated more than once. In both cases, all but one reference is consumed by the preprocessor or compiler. A final patch converts a handful of commented assertions into "real" ones. Some existing validation code can done more simply with assertions, so over time such cases will be converted. For now though, this series adds this assertion capability. -Alex Alex Elder (4): net: ipa: fix init header command validation net: ipa: fix IPA validation net: ipa: introduce ipa_assert() net: ipa: activate some commented assertions drivers/net/ipa/Makefile | 2 +- drivers/net/ipa/gsi_trans.c | 8 ++--- drivers/net/ipa/ipa_assert.h | 50 ++++++++++++++++++++++++++++++++ drivers/net/ipa/ipa_cmd.c | 53 ++++++++++++++++++++++------------ drivers/net/ipa/ipa_cmd.h | 6 ++-- drivers/net/ipa/ipa_endpoint.c | 6 ++-- drivers/net/ipa/ipa_main.c | 6 ++-- drivers/net/ipa/ipa_mem.c | 6 ++-- drivers/net/ipa/ipa_reg.h | 7 +++-- drivers/net/ipa/ipa_table.c | 11 ++++--- drivers/net/ipa/ipa_table.h | 6 ++-- 11 files changed, 115 insertions(+), 46 deletions(-) create mode 100644 drivers/net/ipa/ipa_assert.h