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| author | Greg Kroah-Hartman <gregkh@google.com> | 2018-04-30 05:54:58 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@google.com> | 2018-04-30 05:54:58 -0700 |
| commit | 12ef385f51fecec81b6a690da98d9ee5bb96e887 (patch) | |
| tree | a918e09f086840ad9407dd445bda5ebfe758f4cb /arch/s390/kernel/alternative.c | |
| parent | 23eaecc37dfb0aa51cf131c32cb05784ef84d3be (diff) | |
| parent | 34a220d573fcb5d66ad466611eb80f65b6af98d4 (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.c | 112 |
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); +} |
