summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/vmlinux.lds.S
diff options
context:
space:
mode:
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2015-03-19 16:42:26 +0000
committerWill Deacon <will.deacon@arm.com>2015-03-19 19:21:56 +0000
commit06f75a1f6200042aa36ad40afb44dd72107b25d6 (patch)
tree84f134705f009d74aba8637f25da3f887ea40c08 /arch/arm64/kernel/vmlinux.lds.S
parent06e5801b8cb3fc057d88cb4dc03c0b64b2744cda (diff)
ARM, arm64: kvm: get rid of the bounce page
The HYP init bounce page is a runtime construct that ensures that the HYP init code does not cross a page boundary. However, this is something we can do perfectly well at build time, by aligning the code appropriately. For arm64, we just align to 4 KB, and enforce that the code size is less than 4 KB, regardless of the chosen page size. For ARM, the whole code is less than 256 bytes, so we tweak the linker script to align at a power of 2 upper bound of the code size Note that this also fixes a benign off-by-one error in the original bounce page code, where a bounce page would be allocated unnecessarily if the code was exactly 1 page in size. On ARM, it also fixes an issue with very large kernels reported by Arnd Bergmann, where stub sections with linker emitted veneers could erroneously trigger the size/alignment ASSERT() in the linker script. Tested-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel/vmlinux.lds.S')
-rw-r--r--arch/arm64/kernel/vmlinux.lds.S17
1 files changed, 11 insertions, 6 deletions
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 5d9d2dca530d..a2c29865c3fe 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -23,10 +23,14 @@ jiffies = jiffies_64;
#define HYPERVISOR_TEXT \
/* \
- * Force the alignment to be compatible with \
- * the vectors requirements \
+ * Align to 4 KB so that \
+ * a) the HYP vector table is at its minimum \
+ * alignment of 2048 bytes \
+ * b) the HYP init code will not cross a page \
+ * boundary if its size does not exceed \
+ * 4 KB (see related ASSERT() below) \
*/ \
- . = ALIGN(2048); \
+ . = ALIGN(SZ_4K); \
VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \
*(.hyp.idmap.text) \
VMLINUX_SYMBOL(__hyp_idmap_text_end) = .; \
@@ -163,10 +167,11 @@ SECTIONS
}
/*
- * The HYP init code can't be more than a page long.
+ * The HYP init code can't be more than a page long,
+ * and should not cross a page boundary.
*/
-ASSERT(((__hyp_idmap_text_start + PAGE_SIZE) > __hyp_idmap_text_end),
- "HYP init code too big")
+ASSERT(__hyp_idmap_text_end - (__hyp_idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
+ "HYP init code too big or misaligned")
/*
* If padding is applied before .head.text, virt<->phys conversions will fail.