diff options
| author | John Baldwin <jhb@FreeBSD.org> | 2025-09-16 11:21:39 +0000 |
|---|---|---|
| committer | John Baldwin <jhb@FreeBSD.org> | 2025-09-16 11:21:39 +0000 |
| commit | 7314f78b240bdbf2bcec07e3d5a475e37941bb6b (patch) | |
| tree | 8d1c11ec282fb4d1d39dbdaf0e1c4c770d21ded1 | |
| parent | da20d88599d52667c9cd422632302cf5e2e19938 (diff) | |
aarch64: Clarify the initial adjustments to sp for kernel exception entry
The first store-pair instruction in save_registers_head decrements the
stack pointer to create room for most of the trapframe (and the
redzone area for nested exceptions). However, the expression was a
bit non-intuitive as it was using an expression without a leading
negative sign to adjust the stack pointer. Rewrite the expression so
that it is more clearly a negative adjustment to the stack pointer.
Suggested by: andrew
Reviewed by: andrew
Sponsored by: AFRL, DARPA
Differential Revision: https://reviews.freebsd.org/D52514
| -rw-r--r-- | sys/arm64/arm64/exception.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sys/arm64/arm64/exception.S b/sys/arm64/arm64/exception.S index 13095def8b00..6e673fbe5a43 100644 --- a/sys/arm64/arm64/exception.S +++ b/sys/arm64/arm64/exception.S @@ -43,9 +43,9 @@ .macro save_registers_head el .if \el == 1 mov x18, sp - stp x0, x1, [sp, #(TF_X - TF_SIZE - 128)]! + stp x0, x1, [sp, #-(TF_SIZE - TF_X + 128)]! .else - stp x0, x1, [sp, #(TF_X - TF_SIZE)]! + stp x0, x1, [sp, #-(TF_SIZE - TF_X)]! .endif stp x2, x3, [sp, #(2 * 8)] stp x4, x5, [sp, #(4 * 8)] |