illumos gate

I attempted to compile illumos from an NFS mounted directory today. I ran into a failure coming from cpcgen that stated

cpcgen: no platforms found or matched

After taking a look at the source code I found that this loop was only finding the dir entrires . and .. for the directory usr/src/data/amdpc even though this directory contains two json files. Because of this cpcgen_maps would remain null causing cpcgen to kick back a error and derail the build.

To try and narrow down the issue I created the following minimum reproducible program.

#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>

void run() {
        DIR *dir = opendir(".");
        if (dir == NULL)
                printf("could not open current dir\n");
        struct dirent *d;
        while (d = readdir(dir))
                printf("%s\n", d->d_name);
}

When compiled as a 64-bit binary, this program sees all the expected files in the amdpc directory referenced above. However, when compiled as a 32-bit binary, it only sees the .. and . entries. Peeling back another layer to look at readdir, I immediately noticed that someone had encountered this pain and solved it in the function that directly follows readdir64.

Modifying the above program to the following shows that using readdir64 instead of readdir does produce the expected result from a 32 bit binary on a 64 bit system.

#include <sys/types.h>
#include <dirent.h>
#include <stdio.h>

void run() {
        DIR *dir = opendir(".");
        if (dir == NULL)
                printf("could not open current dir\n");
        struct dirent *d;
        while (d = readdir(dir))
                printf("%s\n", d->d_name);
}

void run64() {
        DIR *dir = opendir(".");
        if (dir == NULL)
                printf("could not open current dir\n");
        struct dirent64 *d;
        while (d = readdir64(dir))
                printf("%s\n", d->d_name);
}

int main() {
        printf("run\n");
        run();
        printf("run64\n");
        run64();
        return 0;
}

ry@masaka:/kdev/illumos/usr/src/data/amdpmc$ /kdev/readdir-fail/readdir-fail32
run
.
..
run64
.
..
f19h_zen3_core.json
f17h_zen2_core.json
.make.state
Makefile
f17h_zen1_core.json
README

The following patch allows a build from an NFS mounted directory to get further on my system.

diff --git a/usr/src/tools/cpcgen/cpcgen.c b/usr/src/tools/cpcgen/cpcgen.c
index 779a782cc6..320cba52f7 100644
--- a/usr/src/tools/cpcgen/cpcgen.c
+++ b/usr/src/tools/cpcgen/cpcgen.c
@@ -642,7 +642,7 @@ static void
 cpcgen_read_amd(const char *datadir, const char *platform)
 {
     DIR *dir;
-    struct dirent *d;
+    struct dirent64 *d;
     const char *suffix = ".json";
     const size_t slen = strlen(suffix);

@@ -650,7 +650,7 @@ cpcgen_read_amd(const char *datadir, const char *platform)
         err(EXIT_FAILURE, "failed to open directory %s", datadir);
     }

-    while ((d = readdir(dir)) != NULL) {
+    while ((d = readdir64(dir)) != NULL) {
         char *name, *c;
         cpc_map_t *map;
         nvlist_t *parsed;

However, I'm not sure if this would break things on an actual 32 bit system.