1573097 - Invalid casts in instance.c

Status: RESOLVED FIXED

(NSS :: Libraries, defect, P3)

Description

[Martin Thomson [:mt:]]

cl on Windows complains of an invalid cast in instance.c:

...\nss\lib\ckfw\instance.c(550): warning C4312: 'type cast': conversion from 'CK_SESSION_HANDLE' to 'const void *' of greater size

This probably benign, but we should build a function that performs this conversion AND statically asserts that the conversion is lossless, i.e.:

PR_STATIC_ASSERT(sizeof(CK_SESSION_HANDLE) <= sizeof(void*));

That function might need to be structured so that it suppresses the warning, but we can probably use uintptr_t as an intermediate value.

Comment 2

[Jimmy Tan]

Hello, although I am new to this community I would love to attempt contributing to this bug. Thanks

Comment 3

[Martin Thomson [:mt:]]

If you can make some changes to instance.c that makes the warnings go away, that would be greatly appreciated. I would start with reproducing the problem on a Windows build. Then take a look at the code to see what might be changed to fix it.

Comment 4

[Jimmy Tan]

Sorry, I realized my build is done in a linux environment. Thanks for your time

Comment 5

[Somdatta]

I would like to work on this bug.

Comment 6

[Dana Keeler (she/her) (use needinfo) [:keeler]]

Please see the contribution documentation at https://firefox-source-docs.mozilla.org/.

Comment 7

[Somdatta]

Okay

Comment 8

[Somdatta]

Attachment: Bug 1573097- Invalid casts in instance.c r?mt

Comment 9

[Ho Cheung]

Attachment: Bug 1573097 - Fix Invalid casts in instance.c r=mt

Add the CKSessionHandleToVoidPtr function, which performs the
conversion from CK_SESSION_HANDLE to const void* using uintptr_t
as an intermediate value. This function is then used in the
nssCKFWHash_Add function call to avoid the warning and ensure
the conversion is lossless.

Comment 10

[Mathew Hodson]

The patch for this bug should be for the NSS repo right? The code lives there and then Firefox vendors it into mozilla-central when NSS releases a new version.

Comment 11

[Kai Engert (:KaiE:)]

https://hg.mozilla.org/projects/nss/rev/38f963acc7afac2be655cff54d90d62cfe3ea047

Comment 12

[John Schanck [:jschanck]]

Attachment: Bug 1573097 - clang format. r=#nss-reviewers

Comment 13

[John Schanck [:jschanck]]

https://hg.mozilla.org/projects/nss/rev/3a65228bef69e531f443037677930365faa05060