[PATCH v2] x86/kaslr: Remove two redundant if checks

From: Thorsten Blum

Date: Fri Jul 31 2026 - 03:44:42 EST


The loop in slots_fetch_random() either returns the slot address or
exits with i == slot_area_index, making the if check redundant. Drop it.

In choose_random_location(), the if (*output != random_addr) check used
to guard an add_identity_map() call. Commit 8570978ea030
("x86/boot/compressed/64: Don't pre-map memory in KASLR code") removed
that call and the check now only guards an assignment. Remove it.

No functional change.

Signed-off-by: Thorsten Blum <thorsten.blum@xxxxxxxxx>
---
Changes in v2:
- Explain why the check in choose_random_location() is redundant (Boris)
- Reword subject
- v1: https://lore.kernel.org/r/20260714205752.133163-2-thorsten.blum@xxxxxxxxx/
---
arch/x86/boot/compressed/kaslr.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 8e4bf5365ac6..181257a6e0aa 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -544,8 +544,7 @@ static u64 slots_fetch_random(void)
return slot_areas[i].addr + ((u64)slot * CONFIG_PHYSICAL_ALIGN);
}

- if (i == slot_area_index)
- debug_putstr("slots_fetch_random() failed!?\n");
+ debug_putstr("slots_fetch_random() failed!?\n");
return 0;
}

@@ -893,14 +892,10 @@ void choose_random_location(unsigned long input,

/* Walk available memory entries to find a random address. */
random_addr = find_random_phys_addr(min_addr, output_size);
- if (!random_addr) {
+ if (!random_addr)
warn("Physical KASLR disabled: no suitable memory region!");
- } else {
- /* Update the new physical address location. */
- if (*output != random_addr)
- *output = random_addr;
- }
-
+ else
+ *output = random_addr;

/* Pick random virtual address starting from LOAD_PHYSICAL_ADDR. */
if (IS_ENABLED(CONFIG_X86_64))