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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>
Subject: [PATCH 4.4 11/50] s390: enable CPU alternatives unconditionally
Date: Fri, 27 Apr 2018 15:58:13 +0200	[thread overview]
Message-ID: <20180427135656.368223813@linuxfoundation.org> (raw)
In-Reply-To: <20180427135655.623669681@linuxfoundation.org>

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Martin Schwidefsky <schwidefsky@de.ibm.com>


From: Heiko Carstens <heiko.carstens@de.ibm.com>

[ Upstream commit 049a2c2d486e8cc82c5cd79fa479c5b105b109e9 ]

Remove the CPU_ALTERNATIVES config option and enable the code
unconditionally. The config option was only added to avoid a conflict
with the named saved segment support. Since that code is gone there is
no reason to keep the CPU_ALTERNATIVES config option.

Just enable it unconditionally to also reduce the number of config
options and make it less likely that something breaks.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/s390/Kconfig                   |   16 ----------------
 arch/s390/include/asm/alternative.h |   20 +++-----------------
 arch/s390/kernel/Makefile           |    3 +--
 arch/s390/kernel/module.c           |   15 ++++++---------
 4 files changed, 10 insertions(+), 44 deletions(-)

--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -705,22 +705,6 @@ config SECCOMP
 
 	  If unsure, say Y.
 
-config ALTERNATIVES
-	def_bool y
-	prompt "Patch optimized instructions for running CPU type"
-	help
-	  When enabled the kernel code is compiled with additional
-	  alternative instructions blocks optimized for newer CPU types.
-	  These alternative instructions blocks are patched at kernel boot
-	  time when running CPU supports them. This mechanism is used to
-	  optimize some critical code paths (i.e. spinlocks) for newer CPUs
-	  even if kernel is build to support older machine generations.
-
-	  This mechanism could be disabled by appending "noaltinstr"
-	  option to the kernel command line.
-
-	  If unsure, say Y.
-
 endmenu
 
 menu "Power Management"
--- a/arch/s390/include/asm/alternative.h
+++ b/arch/s390/include/asm/alternative.h
@@ -15,14 +15,9 @@ struct alt_instr {
 	u8  replacementlen;	/* length of new instruction */
 } __packed;
 
-#ifdef CONFIG_ALTERNATIVES
-extern void apply_alternative_instructions(void);
-extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
-#else
-static inline void apply_alternative_instructions(void) {};
-static inline void apply_alternatives(struct alt_instr *start,
-				      struct alt_instr *end) {};
-#endif
+void apply_alternative_instructions(void);
+void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+
 /*
  * |661:       |662:	  |6620      |663:
  * +-----------+---------------------+
@@ -109,7 +104,6 @@ static inline void apply_alternatives(st
 	b_altinstr(num)":\n\t" altinstr "\n" e_altinstr(num) ":\n"	\
 	INSTR_LEN_SANITY_CHECK(altinstr_len(num))
 
-#ifdef CONFIG_ALTERNATIVES
 /* alternative assembly primitive: */
 #define ALTERNATIVE(oldinstr, altinstr, facility) \
 	".pushsection .altinstr_replacement, \"ax\"\n"			\
@@ -130,14 +124,6 @@ static inline void apply_alternatives(st
 	ALTINSTR_ENTRY(facility1, 1)					\
 	ALTINSTR_ENTRY(facility2, 2)					\
 	".popsection\n"
-#else
-/* Alternative instructions are disabled, let's put just oldinstr in */
-#define ALTERNATIVE(oldinstr, altinstr, facility) \
-	oldinstr "\n"
-
-#define ALTERNATIVE_2(oldinstr, altinstr1, facility1, altinstr2, facility2) \
-	oldinstr "\n"
-#endif
 
 /*
  * Alternative instructions for different CPU types or capabilities.
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -44,7 +44,7 @@ obj-y	+= processor.o sys_s390.o ptrace.o
 obj-y	+= debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o
 obj-y	+= sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o
 obj-y	+= runtime_instr.o cache.o dumpstack.o
-obj-y	+= entry.o reipl.o relocate_kernel.o
+obj-y	+= entry.o reipl.o relocate_kernel.o alternative.o
 
 extra-y				+= head.o head64.o vmlinux.lds
 
@@ -62,7 +62,6 @@ obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o ftrace.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_UPROBES)		+= uprobes.o
-obj-$(CONFIG_ALTERNATIVES)	+= alternative.o
 
 obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o perf_cpum_cf.o perf_cpum_sf.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_cpum_cf_events.o
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -428,16 +428,13 @@ int module_finalize(const Elf_Ehdr *hdr,
 	const Elf_Shdr *s;
 	char *secstrings;
 
-	if (IS_ENABLED(CONFIG_ALTERNATIVES)) {
-		secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-		for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
-			if (!strcmp(".altinstructions",
-				    secstrings + s->sh_name)) {
-				/* patch .altinstructions */
-				void *aseg = (void *)s->sh_addr;
+	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
+		if (!strcmp(".altinstructions", secstrings + s->sh_name)) {
+			/* patch .altinstructions */
+			void *aseg = (void *)s->sh_addr;
 
-				apply_alternatives(aseg, aseg + s->sh_size);
-			}
+			apply_alternatives(aseg, aseg + s->sh_size);
 		}
 	}
 

  parent reply	other threads:[~2018-04-27 13:58 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-27 13:58 [PATCH 4.4 00/50] 4.4.130-stable review Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 01/50] cifs: do not allow creating sockets except with SMB1 posix exensions Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 02/50] x86/tsc: Prevent 32bit truncation in calc_hpet_ref() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 03/50] perf: Return proper values for user stack errors Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 04/50] staging: ion : Donnot wakeup kswapd in ion system alloc Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 05/50] r8152: add Linksys USB3GIGV1 id Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 06/50] Input: drv260x - fix initializing overdrive voltage Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 07/50] ath9k_hw: check if the chip failed to wake up Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 08/50] jbd2: fix use after free in kjournald2() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 09/50] Revert "ath10k: send (re)assoc peer command when NSS changed" Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 10/50] s390: introduce CPU alternatives Greg Kroah-Hartman
2018-04-27 13:58 ` Greg Kroah-Hartman [this message]
2018-04-27 13:58 ` [PATCH 4.4 12/50] KVM: s390: wire up bpb feature Greg Kroah-Hartman
2018-04-27 15:10   ` Christian Borntraeger
2018-04-27 15:17     ` Greg Kroah-Hartman
2018-04-27 15:46       ` Greg Kroah-Hartman
2018-04-27 15:53         ` Christian Borntraeger
2018-04-29  7:51           ` Martin Schwidefsky
2018-04-30 18:17             ` Greg Kroah-Hartman
2018-04-30 18:30               ` Christian Borntraeger
2018-04-27 13:58 ` [PATCH 4.4 13/50] s390: scrub registers on kernel entry and KVM exit Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 14/50] s390: add optimized array_index_mask_nospec Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 15/50] s390/alternative: use a copy of the facility bit mask Greg Kroah-Hartman
2018-05-04  7:37   ` Jiri Slaby
2018-05-04  7:41     ` Jiri Slaby
2018-05-04 22:18     ` Greg Kroah-Hartman
2018-05-07  6:07       ` Martin Schwidefsky
2018-05-08  7:20         ` Greg Kroah-Hartman
2018-05-12 19:44           ` Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 16/50] s390: add options to change branch prediction behaviour for the kernel Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 17/50] s390: run user space and KVM guests with modified branch prediction Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 18/50] s390: introduce execute-trampolines for branches Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 19/50] s390: Replace IS_ENABLED(EXPOLINE_*) with IS_ENABLED(CONFIG_EXPOLINE_*) Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 20/50] s390: do not bypass BPENTER for interrupt system calls Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 21/50] s390/entry.S: fix spurious zeroing of r0 Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 22/50] s390: move nobp parameter functions to nospec-branch.c Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 23/50] s390: add automatic detection of the spectre defense Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 24/50] s390: report spectre mitigation via syslog Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 25/50] s390: add sysfs attributes for spectre Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 26/50] s390: correct nospec auto detection init order Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 27/50] s390: correct module section names for expoline code revert Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 28/50] bonding: do not set slave_dev npinfo before slave_enable_netpoll in bond_enslave Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 29/50] KEYS: DNS: limit the length of option strings Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 30/50] l2tp: check sockaddr length in pppol2tp_connect() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 31/50] net: validate attribute sizes in neigh_dump_table() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 32/50] llc: delete timers synchronously in llc_sk_free() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 33/50] tcp: dont read out-of-bounds opsize Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 34/50] team: avoid adding twice the same option to the event list Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 35/50] team: fix netconsole setup over team Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 36/50] packet: fix bitfield update race Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 37/50] pppoe: check sockaddr length in pppoe_connect() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 38/50] vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 39/50] sctp: do not check port in sctp_inet6_cmp_addr Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 40/50] llc: hold llc_sap before release_sock() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 41/50] llc: fix NULL pointer deref for SOCK_ZAPPED Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 42/50] tipc: add policy for TIPC_NLA_NET_ADDR Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 43/50] net: fix deadlock while clearing neighbor proxy table Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 44/50] tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 45/50] net: af_packet: fix race in PACKET_{R|T}X_RING Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 46/50] ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 47/50] scsi: mptsas: Disable WRITE SAME Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 48/50] cdrom: information leak in cdrom_ioctl_media_changed() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 49/50] s390/cio: update chpid descriptor after resource accessibility event Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.4 50/50] s390/uprobes: implement arch_uretprobe_is_alive() Greg Kroah-Hartman
2018-04-27 18:15 ` [PATCH 4.4 00/50] 4.4.130-stable review Shuah Khan
2018-04-27 18:57 ` Nathan Chancellor
2018-04-27 19:43 ` kernelci.org bot
2018-04-27 20:31 ` Dan Rue
2018-04-28 14:25 ` Guenter Roeck

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