forked from luck/tmp_suning_uos_patched
aedcfbe065
On certain MIPS32 devices, the ftrace tracer "function_graph" uses __lshrdi3() during the capturing of trace data. ftrace then attempts to trace __lshrdi3() which leads to infinite recursion and a stack overflow. Fix this by marking __lshrdi3() as notrace. Mark the other compiler intrinsics as notrace in case the compiler decides to use them in the ftrace path. Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com> Cc: <linux-mips@linux-mips.org> Cc: <linux-kernel@vger.kernel.org> Cc: <stable@vger.kernel.org> # 4.2.x- Patchwork: https://patchwork.linux-mips.org/patch/13354/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
30 lines
485 B
C
30 lines
485 B
C
#include <linux/module.h>
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#include "libgcc.h"
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long long notrace __lshrdi3(long long u, word_type b)
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{
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DWunion uu, w;
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word_type bm;
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if (b == 0)
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return u;
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uu.ll = u;
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bm = 32 - b;
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if (bm <= 0) {
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w.s.high = 0;
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w.s.low = (unsigned int) uu.s.high >> -bm;
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} else {
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const unsigned int carries = (unsigned int) uu.s.high << bm;
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w.s.high = (unsigned int) uu.s.high >> b;
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w.s.low = ((unsigned int) uu.s.low >> b) | carries;
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}
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return w.ll;
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}
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EXPORT_SYMBOL(__lshrdi3);
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