sparc64: Allocate sufficient stack space in ftrace stubs. (035df35d) · Commits · 戴 / test

128 bytes is sufficient for the register window save area, but the calling conventions allow the callee to save up to 6 incoming argument registers into the stack frame after the register window save area. This means a minimal stack frame is 176 bytes (128 + (6 * 8)). This fixes random crashes when using the function tracer. Reported-by:

Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

arch/sparc/lib/mcount.S

+4 −4

Original line number	Diff line number	Diff line
		@@ -34,7 +34,7 @@ mcount:
		cmp %g1, %g2
		be,pn %icc, 1f
		mov %i7, %g3
		save %sp, -128, %sp
		save %sp, -176, %sp
		mov %g3, %o1
		jmpl %g1, %o7
		mov %i7, %o0
		@@ -56,7 +56,7 @@ mcount:
		nop
		5: mov %i7, %g2
		mov %fp, %g3
		save %sp, -128, %sp
		save %sp, -176, %sp
		mov %g2, %l0
		ba,pt %xcc, ftrace_graph_caller
		mov %g3, %l1
		@@ -85,7 +85,7 @@ ftrace_caller:
		lduw [%g1 + %lo(function_trace_stop)], %g1
		brnz,pn %g1, ftrace_stub
		mov %fp, %g3
		save %sp, -128, %sp
		save %sp, -176, %sp
		mov %g2, %o1
		mov %g2, %l0
		mov %g3, %l1
		@@ -120,7 +120,7 @@ ENTRY(ftrace_graph_caller)
		END(ftrace_graph_caller)

		ENTRY(return_to_handler)
		save %sp, -128, %sp
		save %sp, -176, %sp
		call ftrace_return_to_handler
		mov %fp, %o0
		jmpl %o0 + 8, %g0

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