Make sure stack frames are 16-byte-aligned #597
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The x86-64 ABI requires 16b-aligned stack frames. Make sure the initial stack frame is 16b-aligned when entering stage2_main(). Make stage2_main() a diverging function since one shall never attempt to return from it. Signed-off-by: Peter Fang <[email protected]>
startup_64 is now stripped-down enough that we no longer need %r8/%r9 as intermediary registers between stage2 and svsm_start(). Use %rdi and %rsi directly in stage2 and pass them straight to svsm_start(). Signed-off-by: Peter Fang <[email protected]>
The x86-64 ABI requires 16b-aligned stack frames. Make sure the initial stack frame is 16b-aligned when entering svsm_start(). Make svsm_start() a diverging function since one shall never attempt to return from it. Signed-off-by: Peter Fang <[email protected]>
Add align_down() in addition to align_up() to the Address trait, and use
the generic align_{up,down}() and is_aligned() calls to reduce code
duplication.
Signed-off-by: Peter Fang <[email protected]>
The x86-64 ABI requires 16b-aligned stack frames. Make sure VMKernelStack::top_of_stack() always returns a 16b-aligned address, regardless of the base address. Signed-off-by: Peter Fang <[email protected]>
The x86-64 ABI requires 16b-aligned stack frames. Make sure AP's initial stack frame is 16b-aligned when transferring control to the Rust startup function. Make start_ap() a diverging function since one shall never attempt to return from it. Signed-off-by: Peter Fang <[email protected]>
The x86-64 ABI requires 16b-aligned stack frames. Make sure every kernel/user task has a 16b-aligned kernel stack frame when control is transferred to its function entry point. Make sure user stack frames are always 16b-aligned as well. No functional change intended. The intent of this commit is to make clear that stack alignment is enforced and actively checked in debug builds. Signed-off-by: Peter Fang <[email protected]>
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The x86-64 ABI requires 16b-aligned stack frames. Stack misalignment can sometimes lead to hard-to-debug segfaults because x86-64 code that follows the calling convention can assume that stack frames are 16b-aligned. This patch series makes sure this requirement is respected at various transition points in SVSM.