Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64 systems") and 982792c782ef ("x86, mm: probe memory block size for generic x86 64bit") introduced large block sizes for x86. This made it possible to have multiple sections per memory block where previously, there was a only every one section per block. Since blocks consist of contiguous ranges of section, there can be holes in the blocks where sections are not present. If one attempts to offline such a block, a crash occurs since the code is not designed to deal with this. This patch is a quick fix to gaurd against the crash by not allowing blocks with non-present sections to be offlined. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=107781
Unified · Split
| @@ -303,6 +303,10 @@ static int memory_subsys_offline(struct device *dev) · 302 unmodified lines | |||
| 303 | if (mem->state == MEM_OFFLINE) | 303 | if (mem->state == MEM_OFFLINE) |
| 304 | return 0; | 304 | return 0; |
| 305 | 305 | ||
| 306 | /* Can't offline block with non-present sections */ | ||
| 307 | if (mem->section_count != sections_per_block) | ||
| 308 | return -EINVAL; | ||
| 309 | |||
| 306 | return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); | 310 | return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); |
| 307 | } | 311 | } |
| 308 | 312 | ||