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-rw-r--r--arch/s390/kernel/Makefile1
-rw-r--r--arch/s390/kernel/base.S24
-rw-r--r--arch/s390/kernel/entry.S105
-rw-r--r--arch/s390/kernel/irq.c5
-rw-r--r--arch/s390/kernel/nospec-branch.c43
-rw-r--r--arch/s390/kernel/nospec-sysfs.c21
-rw-r--r--arch/s390/kernel/perf_cpum_sf.c4
-rw-r--r--arch/s390/kernel/reipl.S5
-rw-r--r--arch/s390/kernel/swsusp.S10
9 files changed, 96 insertions, 122 deletions
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 8ccfbf22ecbb..c4d4d4ef5e58 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -49,6 +49,7 @@ obj-y += nospec-branch.o
extra-y += head.o head64.o vmlinux.lds
+obj-$(CONFIG_SYSFS) += nospec-sysfs.o
CFLAGS_REMOVE_nospec-branch.o += $(CC_FLAGS_EXPOLINE)
obj-$(CONFIG_MODULES) += s390_ksyms.o module.o
diff --git a/arch/s390/kernel/base.S b/arch/s390/kernel/base.S
index 326f717df587..61fca549a93b 100644
--- a/arch/s390/kernel/base.S
+++ b/arch/s390/kernel/base.S
@@ -8,18 +8,22 @@
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
+#include <asm/nospec-insn.h>
#include <asm/ptrace.h>
#include <asm/sigp.h>
+ GEN_BR_THUNK %r9
+ GEN_BR_THUNK %r14
+
ENTRY(s390_base_mcck_handler)
basr %r13,0
0: lg %r15,__LC_PANIC_STACK # load panic stack
aghi %r15,-STACK_FRAME_OVERHEAD
larl %r1,s390_base_mcck_handler_fn
- lg %r1,0(%r1)
- ltgr %r1,%r1
+ lg %r9,0(%r1)
+ ltgr %r9,%r9
jz 1f
- basr %r14,%r1
+ BASR_EX %r14,%r9
1: la %r1,4095
lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)
lpswe __LC_MCK_OLD_PSW
@@ -36,10 +40,10 @@ ENTRY(s390_base_ext_handler)
basr %r13,0
0: aghi %r15,-STACK_FRAME_OVERHEAD
larl %r1,s390_base_ext_handler_fn
- lg %r1,0(%r1)
- ltgr %r1,%r1
+ lg %r9,0(%r1)
+ ltgr %r9,%r9
jz 1f
- basr %r14,%r1
+ BASR_EX %r14,%r9
1: lmg %r0,%r15,__LC_SAVE_AREA_ASYNC
ni __LC_EXT_OLD_PSW+1,0xfd # clear wait state bit
lpswe __LC_EXT_OLD_PSW
@@ -56,10 +60,10 @@ ENTRY(s390_base_pgm_handler)
basr %r13,0
0: aghi %r15,-STACK_FRAME_OVERHEAD
larl %r1,s390_base_pgm_handler_fn
- lg %r1,0(%r1)
- ltgr %r1,%r1
+ lg %r9,0(%r1)
+ ltgr %r9,%r9
jz 1f
- basr %r14,%r1
+ BASR_EX %r14,%r9
lmg %r0,%r15,__LC_SAVE_AREA_SYNC
lpswe __LC_PGM_OLD_PSW
1: lpswe disabled_wait_psw-0b(%r13)
@@ -116,7 +120,7 @@ ENTRY(diag308_reset)
larl %r4,.Lcontinue_psw # Restore PSW flags
lpswe 0(%r4)
.Lcontinue:
- br %r14
+ BR_EX %r14
.align 16
.Lrestart_psw:
.long 0x00080000,0x80000000 + .Lrestart_part2
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index c63730326215..5416d5d68308 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -23,6 +23,7 @@
#include <asm/vx-insn.h>
#include <asm/setup.h>
#include <asm/nmi.h>
+#include <asm/nospec-insn.h>
__PT_R0 = __PT_GPRS
__PT_R1 = __PT_GPRS + 8
@@ -225,74 +226,16 @@ _PIF_WORK = (_PIF_PER_TRAP)
.popsection
.endm
-#ifdef CONFIG_EXPOLINE
-
- .macro GEN_BR_THUNK name,reg,tmp
- .section .text.\name,"axG",@progbits,\name,comdat
- .globl \name
- .hidden \name
- .type \name,@function
-\name:
- .cfi_startproc
-#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
- exrl 0,0f
-#else
- larl \tmp,0f
- ex 0,0(\tmp)
-#endif
- j .
-0: br \reg
- .cfi_endproc
- .endm
-
- GEN_BR_THUNK __s390x_indirect_jump_r1use_r9,%r9,%r1
- GEN_BR_THUNK __s390x_indirect_jump_r1use_r14,%r14,%r1
- GEN_BR_THUNK __s390x_indirect_jump_r11use_r14,%r14,%r11
-
- .macro BASR_R14_R9
-0: brasl %r14,__s390x_indirect_jump_r1use_r9
- .pushsection .s390_indirect_branches,"a",@progbits
- .long 0b-.
- .popsection
- .endm
-
- .macro BR_R1USE_R14
-0: jg __s390x_indirect_jump_r1use_r14
- .pushsection .s390_indirect_branches,"a",@progbits
- .long 0b-.
- .popsection
- .endm
-
- .macro BR_R11USE_R14
-0: jg __s390x_indirect_jump_r11use_r14
- .pushsection .s390_indirect_branches,"a",@progbits
- .long 0b-.
- .popsection
- .endm
-
-#else /* CONFIG_EXPOLINE */
-
- .macro BASR_R14_R9
- basr %r14,%r9
- .endm
-
- .macro BR_R1USE_R14
- br %r14
- .endm
-
- .macro BR_R11USE_R14
- br %r14
- .endm
-
-#endif /* CONFIG_EXPOLINE */
-
+ GEN_BR_THUNK %r9
+ GEN_BR_THUNK %r14
+ GEN_BR_THUNK %r14,%r11
.section .kprobes.text, "ax"
ENTRY(__bpon)
.globl __bpon
BPON
- BR_R1USE_R14
+ BR_EX %r14
/*
* Scheduler resume function, called by switch_to
@@ -322,7 +265,7 @@ ENTRY(__switch_to)
TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
jz 0f
.insn s,0xb2800000,__LC_LPP # set program parameter
-0: BR_R1USE_R14
+0: BR_EX %r14
.L__critical_start:
@@ -388,7 +331,7 @@ sie_exit:
xgr %r5,%r5
lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
lg %r2,__SF_EMPTY+16(%r15) # return exit reason code
- BR_R1USE_R14
+ BR_EX %r14
.Lsie_fault:
lghi %r14,-EFAULT
stg %r14,__SF_EMPTY+16(%r15) # set exit reason code
@@ -445,7 +388,7 @@ ENTRY(system_call)
lgf %r9,0(%r8,%r10) # get system call add.
TSTMSK __TI_flags(%r12),_TIF_TRACE
jnz .Lsysc_tracesys
- BASR_R14_R9 # call sys_xxxx
+ BASR_EX %r14,%r9 # call sys_xxxx
stg %r2,__PT_R2(%r11) # store return value
.Lsysc_return:
@@ -585,7 +528,7 @@ ENTRY(system_call)
lmg %r3,%r7,__PT_R3(%r11)
stg %r7,STACK_FRAME_OVERHEAD(%r15)
lg %r2,__PT_ORIG_GPR2(%r11)
- BASR_R14_R9 # call sys_xxx
+ BASR_EX %r14,%r9 # call sys_xxx
stg %r2,__PT_R2(%r11) # store return value
.Lsysc_tracenogo:
TSTMSK __TI_flags(%r12),_TIF_TRACE
@@ -609,7 +552,7 @@ ENTRY(ret_from_fork)
lmg %r9,%r10,__PT_R9(%r11) # load gprs
ENTRY(kernel_thread_starter)
la %r2,0(%r10)
- BASR_R14_R9
+ BASR_EX %r14,%r9
j .Lsysc_tracenogo
/*
@@ -685,7 +628,7 @@ ENTRY(pgm_check_handler)
je .Lpgm_return
lgf %r9,0(%r10,%r1) # load address of handler routine
lgr %r2,%r11 # pass pointer to pt_regs
- BASR_R14_R9 # branch to interrupt-handler
+ BASR_EX %r14,%r9 # branch to interrupt-handler
.Lpgm_return:
LOCKDEP_SYS_EXIT
tm __PT_PSW+1(%r11),0x01 # returning to user ?
@@ -962,7 +905,7 @@ ENTRY(psw_idle)
stpt __TIMER_IDLE_ENTER(%r2)
.Lpsw_idle_lpsw:
lpswe __SF_EMPTY(%r15)
- BR_R1USE_R14
+ BR_EX %r14
.Lpsw_idle_end:
/*
@@ -1007,7 +950,7 @@ ENTRY(save_fpu_regs)
.Lsave_fpu_regs_done:
oi __LC_CPU_FLAGS+7,_CIF_FPU
.Lsave_fpu_regs_exit:
- BR_R1USE_R14
+ BR_EX %r14
.Lsave_fpu_regs_end:
/*
@@ -1054,7 +997,7 @@ load_fpu_regs:
.Lload_fpu_regs_done:
ni __LC_CPU_FLAGS+7,255-_CIF_FPU
.Lload_fpu_regs_exit:
- BR_R1USE_R14
+ BR_EX %r14
.Lload_fpu_regs_end:
.L__critical_end:
@@ -1227,7 +1170,7 @@ cleanup_critical:
jl 0f
clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end
jl .Lcleanup_load_fpu_regs
-0: BR_R11USE_R14
+0: BR_EX %r14
.align 8
.Lcleanup_table:
@@ -1257,7 +1200,7 @@ cleanup_critical:
ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
larl %r9,sie_exit # skip forward to sie_exit
- BR_R11USE_R14
+ BR_EX %r14
#endif
.Lcleanup_system_call:
@@ -1315,7 +1258,7 @@ cleanup_critical:
stg %r15,56(%r11) # r15 stack pointer
# set new psw address and exit
larl %r9,.Lsysc_do_svc
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_system_call_insn:
.quad system_call
.quad .Lsysc_stmg
@@ -1325,7 +1268,7 @@ cleanup_critical:
.Lcleanup_sysc_tif:
larl %r9,.Lsysc_tif
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_sysc_restore:
# check if stpt has been executed
@@ -1342,14 +1285,14 @@ cleanup_critical:
mvc 0(64,%r11),__PT_R8(%r9)
lmg %r0,%r7,__PT_R0(%r9)
1: lmg %r8,%r9,__LC_RETURN_PSW
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_sysc_restore_insn:
.quad .Lsysc_exit_timer
.quad .Lsysc_done - 4
.Lcleanup_io_tif:
larl %r9,.Lio_tif
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_io_restore:
# check if stpt has been executed
@@ -1363,7 +1306,7 @@ cleanup_critical:
mvc 0(64,%r11),__PT_R8(%r9)
lmg %r0,%r7,__PT_R0(%r9)
1: lmg %r8,%r9,__LC_RETURN_PSW
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_io_restore_insn:
.quad .Lio_exit_timer
.quad .Lio_done - 4
@@ -1415,17 +1358,17 @@ cleanup_critical:
# prepare return psw
nihh %r8,0xfcfd # clear irq & wait state bits
lg %r9,48(%r11) # return from psw_idle
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_idle_insn:
.quad .Lpsw_idle_lpsw
.Lcleanup_save_fpu_regs:
larl %r9,save_fpu_regs
- BR_R11USE_R14
+ BR_EX %r14,%r11
.Lcleanup_load_fpu_regs:
larl %r9,load_fpu_regs
- BR_R11USE_R14
+ BR_EX %r14,%r11
/*
* Integer constants
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index f41d5208aaf7..590e9394b4dd 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -173,10 +173,9 @@ void do_softirq_own_stack(void)
new -= STACK_FRAME_OVERHEAD;
((struct stack_frame *) new)->back_chain = old;
asm volatile(" la 15,0(%0)\n"
- " basr 14,%2\n"
+ " brasl 14,__do_softirq\n"
" la 15,0(%1)\n"
- : : "a" (new), "a" (old),
- "a" (__do_softirq)
+ : : "a" (new), "a" (old)
: "0", "1", "2", "3", "4", "5", "14",
"cc", "memory" );
} else {
diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c
index 9f3b5b382743..d5eed651b5ab 100644
--- a/arch/s390/kernel/nospec-branch.c
+++ b/arch/s390/kernel/nospec-branch.c
@@ -44,24 +44,6 @@ static int __init nospec_report(void)
}
arch_initcall(nospec_report);
-#ifdef CONFIG_SYSFS
-ssize_t cpu_show_spectre_v1(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return sprintf(buf, "Mitigation: __user pointer sanitization\n");
-}
-
-ssize_t cpu_show_spectre_v2(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
- return sprintf(buf, "Mitigation: execute trampolines\n");
- if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
- return sprintf(buf, "Mitigation: limited branch prediction.\n");
- return sprintf(buf, "Vulnerable\n");
-}
-#endif
-
#ifdef CONFIG_EXPOLINE
int nospec_disable = IS_ENABLED(CONFIG_EXPOLINE_OFF);
@@ -112,7 +94,6 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end)
s32 *epo;
/* Second part of the instruction replace is always a nop */
- memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x00, 0x00 }, 4);
for (epo = start; epo < end; epo++) {
instr = (u8 *) epo + *epo;
if (instr[0] == 0xc0 && (instr[1] & 0x0f) == 0x04)
@@ -133,18 +114,34 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end)
br = thunk + (*(int *)(thunk + 2)) * 2;
else
continue;
- if (br[0] != 0x07 || (br[1] & 0xf0) != 0xf0)
+ /* Check for unconditional branch 0x07f? or 0x47f???? */
+ if ((br[0] & 0xbf) != 0x07 || (br[1] & 0xf0) != 0xf0)
continue;
+
+ memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x07, 0x00 }, 4);
switch (type) {
case BRCL_EXPOLINE:
- /* brcl to thunk, replace with br + nop */
insnbuf[0] = br[0];
insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f);
+ if (br[0] == 0x47) {
+ /* brcl to b, replace with bc + nopr */
+ insnbuf[2] = br[2];
+ insnbuf[3] = br[3];
+ } else {
+ /* brcl to br, replace with bcr + nop */
+ }
break;
case BRASL_EXPOLINE:
- /* brasl to thunk, replace with basr + nop */
- insnbuf[0] = 0x0d;
insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f);
+ if (br[0] == 0x47) {
+ /* brasl to b, replace with bas + nopr */
+ insnbuf[0] = 0x4d;
+ insnbuf[2] = br[2];
+ insnbuf[3] = br[3];
+ } else {
+ /* brasl to br, replace with basr + nop */
+ insnbuf[0] = 0x0d;
+ }
break;
}
diff --git a/arch/s390/kernel/nospec-sysfs.c b/arch/s390/kernel/nospec-sysfs.c
new file mode 100644
index 000000000000..8affad5f18cb
--- /dev/null
+++ b/arch/s390/kernel/nospec-sysfs.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/device.h>
+#include <linux/cpu.h>
+#include <asm/facility.h>
+#include <asm/nospec-branch.h>
+
+ssize_t cpu_show_spectre_v1(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+}
+
+ssize_t cpu_show_spectre_v2(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
+ return sprintf(buf, "Mitigation: execute trampolines\n");
+ if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
+ return sprintf(buf, "Mitigation: limited branch prediction\n");
+ return sprintf(buf, "Vulnerable\n");
+}
diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c
index 3d8da1e742c2..b79d51459cf2 100644
--- a/arch/s390/kernel/perf_cpum_sf.c
+++ b/arch/s390/kernel/perf_cpum_sf.c
@@ -744,6 +744,10 @@ static int __hw_perf_event_init(struct perf_event *event)
*/
rate = 0;
if (attr->freq) {
+ if (!attr->sample_freq) {
+ err = -EINVAL;
+ goto out;
+ }
rate = freq_to_sample_rate(&si, attr->sample_freq);
rate = hw_limit_rate(&si, rate);
attr->freq = 0;
diff --git a/arch/s390/kernel/reipl.S b/arch/s390/kernel/reipl.S
index 52aab0bd84f8..6b1b91c17b40 100644
--- a/arch/s390/kernel/reipl.S
+++ b/arch/s390/kernel/reipl.S
@@ -6,8 +6,11 @@
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
+#include <asm/nospec-insn.h>
#include <asm/sigp.h>
+ GEN_BR_THUNK %r14
+
#
# store_status
#
@@ -62,7 +65,7 @@ ENTRY(store_status)
st %r3,__LC_PSW_SAVE_AREA-SAVE_AREA_BASE + 4(%r1)
larl %r2,store_status
stg %r2,__LC_PSW_SAVE_AREA-SAVE_AREA_BASE + 8(%r1)
- br %r14
+ BR_EX %r14
.section .bss
.align 8
diff --git a/arch/s390/kernel/swsusp.S b/arch/s390/kernel/swsusp.S
index 2d6b6e81f812..60a829c77378 100644
--- a/arch/s390/kernel/swsusp.S
+++ b/arch/s390/kernel/swsusp.S
@@ -12,6 +12,7 @@
#include <asm/ptrace.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
+#include <asm/nospec-insn.h>
#include <asm/sigp.h>
/*
@@ -23,6 +24,8 @@
* (see below) in the resume process.
* This function runs with disabled interrupts.
*/
+ GEN_BR_THUNK %r14
+
.section .text
ENTRY(swsusp_arch_suspend)
stmg %r6,%r15,__SF_GPRS(%r15)
@@ -102,7 +105,7 @@ ENTRY(swsusp_arch_suspend)
spx 0x318(%r1)
lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
lghi %r2,0
- br %r14
+ BR_EX %r14
/*
* Restore saved memory image to correct place and restore register context.
@@ -196,11 +199,10 @@ pgm_check_entry:
larl %r15,init_thread_union
ahi %r15,1<<(PAGE_SHIFT+THREAD_ORDER)
larl %r2,.Lpanic_string
- larl %r3,_sclp_print_early
lghi %r1,0
sam31
sigp %r1,%r0,SIGP_SET_ARCHITECTURE
- basr %r14,%r3
+ brasl %r14,_sclp_print_early
larl %r3,.Ldisabled_wait_31
lpsw 0(%r3)
4:
@@ -266,7 +268,7 @@ restore_registers:
/* Return 0 */
lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
lghi %r2,0
- br %r14
+ BR_EX %r14
.section .data..nosave,"aw",@progbits
.align 8
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-23 04:34:33 +0000