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authorGreg Kroah-Hartman <gregkh@google.com>2018-04-30 05:54:58 -0700
committerGreg Kroah-Hartman <gregkh@google.com>2018-04-30 05:54:58 -0700
commit12ef385f51fecec81b6a690da98d9ee5bb96e887 (patch)
treea918e09f086840ad9407dd445bda5ebfe758f4cb /arch/s390/kernel/alternative.c
parent23eaecc37dfb0aa51cf131c32cb05784ef84d3be (diff)
parent34a220d573fcb5d66ad466611eb80f65b6af98d4 (diff)
Merge 4.4.130 into android-4.4
Changes in 4.4.130 cifs: do not allow creating sockets except with SMB1 posix exensions x86/tsc: Prevent 32bit truncation in calc_hpet_ref() perf: Return proper values for user stack errors staging: ion : Donnot wakeup kswapd in ion system alloc r8152: add Linksys USB3GIGV1 id Input: drv260x - fix initializing overdrive voltage ath9k_hw: check if the chip failed to wake up jbd2: fix use after free in kjournald2() Revert "ath10k: send (re)assoc peer command when NSS changed" s390: introduce CPU alternatives s390: enable CPU alternatives unconditionally KVM: s390: wire up bpb feature s390: scrub registers on kernel entry and KVM exit s390: add optimized array_index_mask_nospec s390/alternative: use a copy of the facility bit mask s390: add options to change branch prediction behaviour for the kernel s390: run user space and KVM guests with modified branch prediction s390: introduce execute-trampolines for branches s390: Replace IS_ENABLED(EXPOLINE_*) with IS_ENABLED(CONFIG_EXPOLINE_*) s390: do not bypass BPENTER for interrupt system calls s390/entry.S: fix spurious zeroing of r0 s390: move nobp parameter functions to nospec-branch.c s390: add automatic detection of the spectre defense s390: report spectre mitigation via syslog s390: add sysfs attributes for spectre s390: correct nospec auto detection init order s390: correct module section names for expoline code revert bonding: do not set slave_dev npinfo before slave_enable_netpoll in bond_enslave KEYS: DNS: limit the length of option strings l2tp: check sockaddr length in pppol2tp_connect() net: validate attribute sizes in neigh_dump_table() llc: delete timers synchronously in llc_sk_free() tcp: don't read out-of-bounds opsize team: avoid adding twice the same option to the event list team: fix netconsole setup over team packet: fix bitfield update race pppoe: check sockaddr length in pppoe_connect() vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi sctp: do not check port in sctp_inet6_cmp_addr llc: hold llc_sap before release_sock() llc: fix NULL pointer deref for SOCK_ZAPPED tipc: add policy for TIPC_NLA_NET_ADDR net: fix deadlock while clearing neighbor proxy table tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets net: af_packet: fix race in PACKET_{R|T}X_RING ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy scsi: mptsas: Disable WRITE SAME cdrom: information leak in cdrom_ioctl_media_changed() s390/cio: update chpid descriptor after resource accessibility event s390/uprobes: implement arch_uretprobe_is_alive() Linux 4.4.130 Change-Id: I58646180c70ac61da3e2a602085760881d914eb5 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Diffstat (limited to 'arch/s390/kernel/alternative.c')
-rw-r--r--arch/s390/kernel/alternative.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/arch/s390/kernel/alternative.c b/arch/s390/kernel/alternative.c
new file mode 100644
index 000000000000..b57b293998dc
--- /dev/null
+++ b/arch/s390/kernel/alternative.c
@@ -0,0 +1,112 @@
+#include <linux/module.h>
+#include <asm/alternative.h>
+#include <asm/facility.h>
+#include <asm/nospec-branch.h>
+
+#define MAX_PATCH_LEN (255 - 1)
+
+static int __initdata_or_module alt_instr_disabled;
+
+static int __init disable_alternative_instructions(char *str)
+{
+ alt_instr_disabled = 1;
+ return 0;
+}
+
+early_param("noaltinstr", disable_alternative_instructions);
+
+struct brcl_insn {
+ u16 opc;
+ s32 disp;
+} __packed;
+
+static u16 __initdata_or_module nop16 = 0x0700;
+static u32 __initdata_or_module nop32 = 0x47000000;
+static struct brcl_insn __initdata_or_module nop48 = {
+ 0xc004, 0
+};
+
+static const void *nops[] __initdata_or_module = {
+ &nop16,
+ &nop32,
+ &nop48
+};
+
+static void __init_or_module add_jump_padding(void *insns, unsigned int len)
+{
+ struct brcl_insn brcl = {
+ 0xc0f4,
+ len / 2
+ };
+
+ memcpy(insns, &brcl, sizeof(brcl));
+ insns += sizeof(brcl);
+ len -= sizeof(brcl);
+
+ while (len > 0) {
+ memcpy(insns, &nop16, 2);
+ insns += 2;
+ len -= 2;
+ }
+}
+
+static void __init_or_module add_padding(void *insns, unsigned int len)
+{
+ if (len > 6)
+ add_jump_padding(insns, len);
+ else if (len >= 2)
+ memcpy(insns, nops[len / 2 - 1], len);
+}
+
+static void __init_or_module __apply_alternatives(struct alt_instr *start,
+ struct alt_instr *end)
+{
+ struct alt_instr *a;
+ u8 *instr, *replacement;
+ u8 insnbuf[MAX_PATCH_LEN];
+
+ /*
+ * The scan order should be from start to end. A later scanned
+ * alternative code can overwrite previously scanned alternative code.
+ */
+ for (a = start; a < end; a++) {
+ int insnbuf_sz = 0;
+
+ instr = (u8 *)&a->instr_offset + a->instr_offset;
+ replacement = (u8 *)&a->repl_offset + a->repl_offset;
+
+ if (!__test_facility(a->facility,
+ S390_lowcore.alt_stfle_fac_list))
+ continue;
+
+ if (unlikely(a->instrlen % 2 || a->replacementlen % 2)) {
+ WARN_ONCE(1, "cpu alternatives instructions length is "
+ "odd, skipping patching\n");
+ continue;
+ }
+
+ memcpy(insnbuf, replacement, a->replacementlen);
+ insnbuf_sz = a->replacementlen;
+
+ if (a->instrlen > a->replacementlen) {
+ add_padding(insnbuf + a->replacementlen,
+ a->instrlen - a->replacementlen);
+ insnbuf_sz += a->instrlen - a->replacementlen;
+ }
+
+ s390_kernel_write(instr, insnbuf, insnbuf_sz);
+ }
+}
+
+void __init_or_module apply_alternatives(struct alt_instr *start,
+ struct alt_instr *end)
+{
+ if (!alt_instr_disabled)
+ __apply_alternatives(start, end);
+}
+
+extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
+void __init apply_alternative_instructions(void)
+{
+ apply_alternatives(__alt_instructions, __alt_instructions_end);
+}