diff options
| -rw-r--r-- | arch/s390/include/asm/nospec-insn.h | 13 | ||||
| -rw-r--r-- | arch/s390/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/s390/kernel/mcount.S | 14 |
3 files changed, 23 insertions, 5 deletions
diff --git a/arch/s390/include/asm/nospec-insn.h b/arch/s390/include/asm/nospec-insn.h index 087fc9b972c5..9a56e738d645 100644 --- a/arch/s390/include/asm/nospec-insn.h +++ b/arch/s390/include/asm/nospec-insn.h @@ -2,10 +2,15 @@ #ifndef _ASM_S390_NOSPEC_ASM_H #define _ASM_S390_NOSPEC_ASM_H +#include <asm/alternative-asm.h> +#include <asm/asm-offsets.h> + #ifdef __ASSEMBLY__ #ifdef CONFIG_EXPOLINE +_LC_BR_R1 = __LC_BR_R1 + /* * The expoline macros are used to create thunks in the same format * as gcc generates them. The 'comdat' section flag makes sure that @@ -101,13 +106,21 @@ .endm .macro __THUNK_EX_BR reg,ruse + # Be very careful when adding instructions to this macro! + # The ALTERNATIVE replacement code has a .+10 which targets + # the "br \reg" after the code has been patched. #ifdef CONFIG_HAVE_MARCH_Z10_FEATURES exrl 0,555f j . #else + .ifc \reg,%r1 + ALTERNATIVE "ex %r0,_LC_BR_R1", ".insn ril,0xc60000000000,0,.+10", 35 + j . + .else larl \ruse,555f ex 0,0(\ruse) j . + .endif #endif 555: br \reg .endm diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index dc6c9c604543..39572281e213 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -170,6 +170,7 @@ int main(void) OFFSET(__LC_MACHINE_FLAGS, _lowcore, machine_flags); OFFSET(__LC_GMAP, _lowcore, gmap); OFFSET(__LC_PASTE, _lowcore, paste); + OFFSET(__LC_BR_R1, _lowcore, br_r1_trampoline); /* software defined ABI-relevant lowcore locations 0xe00 - 0xe20 */ OFFSET(__LC_DUMP_REIPL, _lowcore, ipib); /* hardware defined lowcore locations 0x1000 - 0x18ff */ diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S index e499370fbccb..6c1c7d399bf9 100644 --- a/arch/s390/kernel/mcount.S +++ b/arch/s390/kernel/mcount.S @@ -8,12 +8,16 @@ #include <linux/linkage.h> #include <asm/asm-offsets.h> #include <asm/ftrace.h> +#include <asm/nospec-insn.h> #include <asm/ptrace.h> + GEN_BR_THUNK %r1 + GEN_BR_THUNK %r14 + .section .kprobes.text, "ax" ENTRY(ftrace_stub) - br %r14 + BR_EX %r14 #define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE) #define STACK_PTREGS (STACK_FRAME_OVERHEAD) @@ -21,7 +25,7 @@ ENTRY(ftrace_stub) #define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) ENTRY(_mcount) - br %r14 + BR_EX %r14 ENTRY(ftrace_caller) .globl ftrace_regs_caller @@ -49,7 +53,7 @@ ENTRY(ftrace_caller) #endif lgr %r3,%r14 la %r5,STACK_PTREGS(%r15) - basr %r14,%r1 + BASR_EX %r14,%r1 #ifdef CONFIG_FUNCTION_GRAPH_TRACER # The j instruction gets runtime patched to a nop instruction. # See ftrace_enable_ftrace_graph_caller. @@ -64,7 +68,7 @@ ftrace_graph_caller_end: #endif lg %r1,(STACK_PTREGS_PSW+8)(%r15) lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) - br %r1 + BR_EX %r1 #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -77,6 +81,6 @@ ENTRY(return_to_handler) aghi %r15,STACK_FRAME_OVERHEAD lgr %r14,%r2 lmg %r2,%r5,32(%r15) - br %r14 + BR_EX %r14 #endif |