diff options
| author | Jonathan Neuschäfer <j.neuschaefer@gmx.net> | 2017-09-26 01:44:46 +0200 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2017-11-07 12:30:38 +0000 |
| commit | 5a6e389747d37e4ed69d9261187155c83739a649 (patch) | |
| tree | 2fe954449bb7a0db759f6e532a766ebef61d9e12 /src | |
| parent | c90f1d7be0bb41e1e74b5a6f7c4ceb4a2fceada8 (diff) | |
arch/riscv: Use a separate trap stack
This is the lazy solution, as explained in the comment, but it works for
now.
Change-Id: I46e18b6d633280d6409e42462500fbe7c6823b4d
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/21689
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/riscv/trap_util.S | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/arch/riscv/trap_util.S b/src/arch/riscv/trap_util.S index 44cfab7c99..5582a0770c 100644 --- a/src/arch/riscv/trap_util.S +++ b/src/arch/riscv/trap_util.S @@ -128,10 +128,14 @@ trap_entry: .Lsmp_hang: bnez sp, .Lsmp_hang - # TODO: Use the old stack pointer (plus an offset) for exceptions in machine - # mode, to avoid overwriting stack data. - la sp, _estack - addi sp,sp,-MENTRY_FRAME_SIZE + # Use a different stack than in the main context, to to avoid overwriting + # stack data. + # TODO: Maybe use the old stack pointer (plus an offset) instead. But only if + # the previous mode was M, because it would be a very bad idea to use a stack + # pointer provided by unprivileged code! + la sp, _estack + addi sp, sp, -2048 # 2 KiB is half of the stack space + addi sp, sp, -MENTRY_FRAME_SIZE save_tf move a0,sp |