On Mon, 5 Jan 2026 11:42:08 GMT, Martin Doerr <[email protected]> wrote:
>> Or I can call this `_posix_getpwuid_r` function if `isAix()` is true. Is
>> this enough?
>>
>> private static final MethodHandle getpwuid_r = LINKER
>> - .downcallHandle(SYMBOL_LOOKUP.findOrThrow("getpwuid_r"),
>> + .downcallHandle(SYMBOL_LOOKUP.findOrThrow(
>> + OperatingSystem.isAix() ? "_posix_getpwuid_r" :
>> "getpwuid_r"),
>> FunctionDescriptor.of(C_INT, C_INT, C_POINTER,
>> C_POINTER,
>> - C_SIZE_T, C_POINTER));
>> + OperatingSystem.isAix() ? C_INT : C_SIZE_T,
>> + C_POINTER));
>
> Thank you for taking care of it! I appreciate it. This has worked:
>
> diff --git
> a/src/jdk.security.auth/share/classes/com/sun/security/auth/module/UnixSystem.java
>
> b/src/jdk.security.auth/share/classes/com/sun/security/auth/module/UnixSystem.java
> index ee2c5effcf0..3afab6f7974 100644
> ---
> a/src/jdk.security.auth/share/classes/com/sun/security/auth/module/UnixSystem.java
> +++
> b/src/jdk.security.auth/share/classes/com/sun/security/auth/module/UnixSystem.java
> @@ -38,6 +38,8 @@
> import java.lang.invoke.MethodHandle;
> import java.lang.invoke.VarHandle;
>
> +import jdk.internal.util.OperatingSystem;
> +
> import static java.lang.foreign.MemoryLayout.PathElement.groupElement;
>
> /**
> @@ -106,9 +108,9 @@ public class UnixSystem {
> .downcallHandle(SYMBOL_LOOKUP.findOrThrow("getgid"),
> FunctionDescriptor.of(C_INT));
> private static final MethodHandle getpwuid_r = LINKER
> - .downcallHandle(SYMBOL_LOOKUP.findOrThrow("getpwuid_r"),
> +
> .downcallHandle(SYMBOL_LOOKUP.findOrThrow(OperatingSystem.isAix() ?
> "_posix_getpwuid_r" : "getpwuid_r"),
> FunctionDescriptor.of(C_INT, C_INT, C_POINTER, C_POINTER,
> - C_SIZE_T, C_POINTER));
> + OperatingSystem.isAix() ? C_INT : C_SIZE_T,
> C_POINTER));
>
> private static final GroupLayout passwd_layout =
> MemoryLayout.structLayout(
> C_POINTER.withName("pw_name"),
> @@ -136,7 +138,7 @@ public class UnixSystem {
> // sysconf(_SC_GETPW_R_SIZE_MAX) on macOS is 4096 and 1024 on Linux.
> // Not calling sysconf() here because _SC_GETPW_R_SIZE_MAX is different
> // on different platforms.
> - private static final long GETPW_R_SIZE_MAX = 4096L;
> + private static final int GETPW_R_SIZE_MAX = 4096;
>
> /**
> * Instantiate a {@code UnixSystem} and load
>
> Note that `GETPW_R_SIZE_MAX` needs to be an `int` because `long` to `int`
> conversion would require an explicit cast (probably also for arm32). The
> other way round works implicitly.
>
> I'd like to have feedback from the AIX experts as well. They may still be on
> vacation for a couple of days.
>
> We still have a potential problem with the UID parameter. We are using an
> `int`, but the C code expects an `uint32_t`. Some platforms pass 32 bit
> values in 64 bit registers and expect a proper extension (zero for unsigned
> and sign for signed). If the UID becomes larger than INT_MAX, we use sign
> extend which is wrong.
> Not sure of anyone uses so large UIDs and if we could re...
Maybe we can call `Integer.toUnsignedLong()` on `pw_uid` and `pw_gid`? In
`UnixSystem`, they are `long`s.
Also, I want to discuss on the `username` issue again. Do you think it's good
to login successfully without a `UnixPrincipal`? Now that there is a way on AIX
to get it, I'm more inclined to revert the changes made to `UnixLoginModule`.
While the old `Unix.c` seems to support username being `null` we know it would
fail later with an NPE so this has never really worked before. My current
understanding is that silent passing the login without a username might hide a
bug and if the user takes it for granted that there should be a `UnixPrincipal`
there will be a problem sooner or later. In fact, I would suggest we just throw
an exception in `UnixSystem` if `getpwuid_r` cannot find the username.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/28931#discussion_r2662017228
