4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Harvey Hunt <harvey.hunt@xxxxxxxxxx> commit aedcfbe06558a9f53002e82d5be64c6c94687726 upstream. 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@xxxxxxxxxx> Cc: <linux-mips@xxxxxxxxxxxxxx> Cc: <linux-kernel@xxxxxxxxxxxxxxx> Patchwork: https://patchwork.linux-mips.org/patch/13354/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/mips/lib/ashldi3.c | 2 +- arch/mips/lib/ashrdi3.c | 2 +- arch/mips/lib/bswapdi.c | 2 +- arch/mips/lib/bswapsi.c | 2 +- arch/mips/lib/cmpdi2.c | 2 +- arch/mips/lib/lshrdi3.c | 2 +- arch/mips/lib/ucmpdi2.c | 2 +- 7 files changed, 7 insertions(+), 7 deletions(-) --- a/arch/mips/lib/ashldi3.c +++ b/arch/mips/lib/ashldi3.c @@ -2,7 +2,7 @@ #include "libgcc.h" -long long __ashldi3(long long u, word_type b) +long long notrace __ashldi3(long long u, word_type b) { DWunion uu, w; word_type bm; --- a/arch/mips/lib/ashrdi3.c +++ b/arch/mips/lib/ashrdi3.c @@ -2,7 +2,7 @@ #include "libgcc.h" -long long __ashrdi3(long long u, word_type b) +long long notrace __ashrdi3(long long u, word_type b) { DWunion uu, w; word_type bm; --- a/arch/mips/lib/bswapdi.c +++ b/arch/mips/lib/bswapdi.c @@ -1,6 +1,6 @@ #include <linux/module.h> -unsigned long long __bswapdi2(unsigned long long u) +unsigned long long notrace __bswapdi2(unsigned long long u) { return (((u) & 0xff00000000000000ull) >> 56) | (((u) & 0x00ff000000000000ull) >> 40) | --- a/arch/mips/lib/bswapsi.c +++ b/arch/mips/lib/bswapsi.c @@ -1,6 +1,6 @@ #include <linux/module.h> -unsigned int __bswapsi2(unsigned int u) +unsigned int notrace __bswapsi2(unsigned int u) { return (((u) & 0xff000000) >> 24) | (((u) & 0x00ff0000) >> 8) | --- a/arch/mips/lib/cmpdi2.c +++ b/arch/mips/lib/cmpdi2.c @@ -2,7 +2,7 @@ #include "libgcc.h" -word_type __cmpdi2(long long a, long long b) +word_type notrace __cmpdi2(long long a, long long b) { const DWunion au = { .ll = a --- a/arch/mips/lib/lshrdi3.c +++ b/arch/mips/lib/lshrdi3.c @@ -2,7 +2,7 @@ #include "libgcc.h" -long long __lshrdi3(long long u, word_type b) +long long notrace __lshrdi3(long long u, word_type b) { DWunion uu, w; word_type bm; --- a/arch/mips/lib/ucmpdi2.c +++ b/arch/mips/lib/ucmpdi2.c @@ -2,7 +2,7 @@ #include "libgcc.h" -word_type __ucmpdi2(unsigned long long a, unsigned long long b) +word_type notrace __ucmpdi2(unsigned long long a, unsigned long long b) { const DWunion au = {.ll = a}; const DWunion bu = {.ll = b};
