diff options
| author | Philip Redkin <me@rarity.fan> | 2024-11-15 20:36:59 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-03-19 11:05:22 +0100 |
| commit | 631ca8909fd5c62b9fda9edda93924311a78a9c4 (patch) | |
| tree | 3596cad1cb9804115549470b70024081b4924f32 | |
| parent | 89771319e0f11314fcf6d22fcdd0c41e2d157ddc (diff) | |
x86/mm: Check return value from memblock_phys_alloc_range()
At least with CONFIG_PHYSICAL_START=0x100000, if there is < 4 MiB of
contiguous free memory available at this point, the kernel will crash
and burn because memblock_phys_alloc_range() returns 0 on failure,
which leads memblock_phys_free() to throw the first 4 MiB of physical
memory to the wolves.
At a minimum it should fail gracefully with a meaningful diagnostic,
but in fact everything seems to work fine without the weird reserve
allocation.
Signed-off-by: Philip Redkin <me@rarity.fan>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/94b3e98f-96a7-3560-1f76-349eb95ccf7f@rarity.fan
| -rw-r--r-- | arch/x86/mm/init.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 62aa4d66a032..bfa444a7dbb0 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -645,8 +645,13 @@ static void __init memory_map_top_down(unsigned long map_start, */ addr = memblock_phys_alloc_range(PMD_SIZE, PMD_SIZE, map_start, map_end); - memblock_phys_free(addr, PMD_SIZE); - real_end = addr + PMD_SIZE; + if (!addr) { + pr_warn("Failed to release memory for alloc_low_pages()"); + real_end = max(map_start, ALIGN_DOWN(map_end, PMD_SIZE)); + } else { + memblock_phys_free(addr, PMD_SIZE); + real_end = addr + PMD_SIZE; + } /* step_size need to be small so pgt_buf from BRK could cover it */ step_size = PMD_SIZE; |