This is a note to let you know that I've just added the patch titled
arm64: entry.S: Add ventry overflow sanity checks
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-entry.s-add-ventry-overflow-sanity-checks.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c0a650d88704546780aa74617b42f0a0450bfda1
Author: James Morse <james.morse@xxxxxxx>
Date: Tue Mar 15 18:23:58 2022 +0000
arm64: entry.S: Add ventry overflow sanity checks
commit 4330e2c5c04c27bebf89d34e0bc14e6943413067 upstream.
Subsequent patches add even more code to the ventry slots.
Ensure kernels that overflow a ventry slot don't get built.
Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index db137746c6fa..98991aa9d0b1 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -59,6 +59,7 @@
.macro kernel_ventry, el, label, regsize = 64
.align 7
+.Lventry_start\@:
#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
alternative_if ARM64_UNMAP_KERNEL_AT_EL0
.if \el == 0
@@ -116,6 +117,7 @@ alternative_else_nop_endif
mrs x0, tpidrro_el0
#endif
b el\()\el\()_\label
+.org .Lventry_start\@ + 128 // Did we overflow the ventry slot?
.endm
.macro tramp_alias, dst, sym
@@ -1080,6 +1082,7 @@ alternative_else_nop_endif
add x30, x30, #(1b - tramp_vectors)
isb
ret
+.org 1b + 128 // Did we overflow the ventry slot?
.endm
.macro tramp_exit, regsize = 64
