linux_dsm_epyc7002/arch/mips/lib/ucmpdi2.c
Harvey Hunt aedcfbe065 MIPS: lib: Mark intrinsics notrace
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>
2016-05-28 12:35:11 +02:00

22 lines
511 B
C

#include <linux/module.h>
#include "libgcc.h"
word_type notrace __ucmpdi2(unsigned long long a, unsigned long long b)
{
const DWunion au = {.ll = a};
const DWunion bu = {.ll = b};
if ((unsigned int) au.s.high < (unsigned int) bu.s.high)
return 0;
else if ((unsigned int) au.s.high > (unsigned int) bu.s.high)
return 2;
if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
return 0;
else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
return 2;
return 1;
}
EXPORT_SYMBOL(__ucmpdi2);