objtool: Fix stack-swizzle for FRAME_POINTER=y
When objtool encounters the stack-swizzle: mov %rsp, (%[tos]) mov %[tos], %rsp ... pop %rsp Inside a FRAME_POINTER=y build, things go a little screwy because clearly we're not adjusting the cfa->base. This then results in the pop %rsp not being detected as a restore of cfa->base so it will turn into a regular POP and offset the stack, resulting in: kernel/softirq.o: warning: objtool: do_softirq()+0xdb: return with modified stack frame Therefore, have "mov %[tos], %rsp" act like a PUSH (it sorta is anyway) to balance the things out. We're not too concerned with the actual stack_size for frame-pointer builds, since we don't generate ORC data for them anyway. Fixes: aafeb14e ("objtool: Support stack-swizzle") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/YC6UC+rc9KKmQrkd@hirez.programming.kicks-ass.net
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