Re: [Crash-utility] More fixes for kmem on slabs

But your patch does this: @@ -8117,8 +8135,9 @@ kmem_cache_s_array_nodes: "array cache array", RETURN_ON_ERROR)) goto bail_out; - for (i = max_limit = 0; (i < ARRAY_LENGTH(kmem_cache_s_array)) && - cpudata[i]; i++) { + for (i = max_limit = 0; (i < kmem_cache_nr_cpu) + && (i < ARRAY_LENGTH(kmem_cache_s_array)) + && cpudata[i]; i++) { if (!readmem(cpudata[i]+OFFSET(array_cache_limit), KVADDR, &limit, sizeof(int), "array cache limit", RETURN_ON_ERROR)) On "old" slab systems, your new "kmem_cache_nr_cpu" variable remains at its initialized value of zero, and the loop never gets entered. So I don't think you wanted to keep the (i < kmem_cache_nr_cpu) there, right?

> 2) kmem_cache structs can be allocated near enough to the edge of a page > that the old incorrect length crosses the page boundary, even though the > real smaller structure fits in the page. That caused a readmem of the > structure to cross into a coincidentally missing page in the dump. Right -- that was the genesis of the kmem_cache_downsize() function. > This patch fixes both of those (after wrestling ARRAY_LENGTH to the > ground), but *does not* fix the similar page crossing problem when I try > to use a "struct kmem_cache" command on the particular structure at the > end of the page. Yeah, damn, I don't know what can be done for that, aside from some horrific kludge to gdb_readmem_callback() to return successfully even if the readmem() failed.