On Mon, Sep 14, 2020 at 10:23 PM Sean Anderson seanga2@gmail.com wrote:
This allows code to use a construct like `if (gd & gd->...) { ... }` when accessing the global data pointer. Without this change, it was possible for a very early trap to cause _exit_trap to read arbitrary memory. This could cause a second trap, preventing show_regs from being printed.
XIP cannot use locks because flash is not writable. This leaves it vulnerable to the same class of bugs regarding already-pending IPIs as before this series. Fixing that would require finding another method of synchronization, which is outside the scope of this series.
Fixes: 7c6ca03eae ("riscv: additional crash information") Signed-off-by: Sean Anderson seanga2@gmail.com
Changes in v2:
- Set gp early with XIP
arch/riscv/cpu/start.S | 26 +++++++++++++++++++++++--- arch/riscv/lib/interrupts.c | 3 ++- 2 files changed, 25 insertions(+), 4 deletions(-)
Reviewed-by: Bin Meng bin.meng@windriver.com