Dynamically configure machdep->stacksize based on page size. Specifically, set it to 32KB for 16KB pages (default for CONFIG_ARM64_16K_PAGES) and 64KB for 64KB pages, instead of using the hardcoded 16KB ARM64_STACK_SIZE. Update arm64_unwind_frame and arm64_unwind_frame_v2 to use machdep->stacksize for stack_mask calculation instead of ARM64_STACK_SIZE. This fixes unwinding failures when the stack frame crosses the 16KB boundary on a 32KB stack. Signed-off-by: Dean Liao <deanliao(a)google.com&gt; --- arm64.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/arm64.c b/arm64.c index d177092..3ce14aa 100644 --- a/arm64.c +++ b/arm64.c @@ -630,7 +630,22 @@ arm64_init(int when) machdep->last_ptbl_read = 0; machdep->clear_machdep_cache = arm64_clear_machdep_cache; - machdep->stacksize = ARM64_STACK_SIZE; + /* + * Refer to arch/arm64/include/asm/memory.h in kernel source: + * THREAD_SIZE is PAGE_SIZE << THREAD_SIZE_ORDER. + * When CONFIG_VMAP_STACK is enabled, THREAD_SHIFT is at + * least PAGE_SHIFT. + * - 4KB pages -> 16KB stack (ARM64_STACK_SIZE) + * - 16KB pages -> 32KB stack (MIN_THREAD_SHIFT=15 if KASAN + * enabled, or Android default) + * - 64KB pages -> 64KB stack (THREAD_SHIFT=PAGE_SHIFT=16) + */ + if (machdep->pagesize == 16384) + machdep->stacksize = 32768; + else if (machdep->pagesize == 65536) + machdep->stacksize = 65536; + else + machdep->stacksize = ARM64_STACK_SIZE; machdep->flags |= VMEMMAP; machdep->uvtop = arm64_uvtop; machdep->is_uvaddr = arm64_is_uvaddr; @@ -3311,7 +3326,7 @@ arm64_unwind_frame(struct bt_info *bt, struct arm64_stackframe *frame) struct arm64_pt_regs *ptregs; struct machine_specific *ms = machdep->machspec; - stack_mask = (unsigned long)(ARM64_STACK_SIZE) - 1; + stack_mask = machdep->stacksize - 1; fp = frame->fp; low = frame->sp; @@ -3521,7 +3536,7 @@ arm64_unwind_frame_v2(struct bt_info *bt, struct arm64_stackframe *frame, unsigned long irq_stack_ptr; struct machine_specific *ms; - stack_mask = (unsigned long)(ARM64_STACK_SIZE) - 1; + stack_mask = machdep->stacksize - 1; fp = frame->fp; low = frame->sp; -- 2.55.0.rc0.799.gd6f94ed593-goog