diff options
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/alternative.h | 66 | ||||
| -rw-r--r-- | arch/s390/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/s390/include/asm/spinlock.h | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/alternative.c | 30 | ||||
| -rw-r--r-- | arch/s390/kernel/entry.S | 22 | ||||
| -rw-r--r-- | arch/s390/lib/spinlock.c | 4 |
6 files changed, 92 insertions, 34 deletions
diff --git a/arch/s390/include/asm/alternative.h b/arch/s390/include/asm/alternative.h index 16de33750d6c..5b931070be16 100644 --- a/arch/s390/include/asm/alternative.h +++ b/arch/s390/include/asm/alternative.h @@ -2,6 +2,44 @@ #ifndef _ASM_S390_ALTERNATIVE_H #define _ASM_S390_ALTERNATIVE_H +/* + * Each alternative comes with a 32 bit feature field: + * union { + * u32 feature; + * struct { + * u32 ctx : 4; + * u32 type : 8; + * u32 data : 20; + * }; + * } + * + * @ctx is a bitfield, where only one bit must be set. Each bit defines + * in which context an alternative is supposed to be applied to the + * kernel image: + * + * - from the decompressor before the kernel itself is executed + * - from early kernel code from within the kernel + * + * @type is a number which defines the type and with that the type + * specific alternative patching. + * + * @data is additional type specific information which defines if an + * alternative should be applied. + */ + +#define ALT_CTX_LATE 1 +#define ALT_CTX_ALL ALT_CTX_LATE + +#define ALT_TYPE_FACILITY 0 + +#define ALT_DATA_SHIFT 0 +#define ALT_TYPE_SHIFT 20 +#define ALT_CTX_SHIFT 28 + +#define ALT_FACILITY(facility) (ALT_CTX_LATE << ALT_CTX_SHIFT | \ + ALT_TYPE_FACILITY << ALT_TYPE_SHIFT | \ + (facility) << ALT_DATA_SHIFT) + #ifndef __ASSEMBLY__ #include <linux/types.h> @@ -11,12 +49,30 @@ struct alt_instr { s32 instr_offset; /* original instruction */ s32 repl_offset; /* offset to replacement instruction */ - u16 feature; /* feature required for replacement */ + union { + u32 feature; /* feature required for replacement */ + struct { + u32 ctx : 4; /* context */ + u32 type : 8; /* type of alternative */ + u32 data : 20; /* patching information */ + }; + }; u8 instrlen; /* length of original instruction */ } __packed; -void apply_alternative_instructions(void); -void apply_alternatives(struct alt_instr *start, struct alt_instr *end); +extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; + +void __apply_alternatives(struct alt_instr *start, struct alt_instr *end, unsigned int ctx); + +static inline void apply_alternative_instructions(void) +{ + __apply_alternatives(__alt_instructions, __alt_instructions_end, ALT_CTX_LATE); +} + +static inline void apply_alternatives(struct alt_instr *start, struct alt_instr *end) +{ + __apply_alternatives(start, end, ALT_CTX_ALL); +} /* * +---------------------------------+ @@ -51,7 +107,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); #define ALTINSTR_ENTRY(feature, num) \ "\t.long 661b - .\n" /* old instruction */ \ "\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \ - "\t.word " __stringify(feature) "\n" /* feature */ \ + "\t.long " __stringify(feature) "\n" /* feature */ \ "\t.byte " oldinstr_len "\n" /* instruction len */ \ "\t.org . - (" oldinstr_len ") & 1\n" \ "\t.org . - (" oldinstr_len ") + (" altinstr_len(num) ")\n" \ @@ -127,7 +183,7 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end); .macro alt_entry orig_start, orig_end, alt_start, alt_end, feature .long \orig_start - . .long \alt_start - . - .word \feature + .long \feature .byte \orig_end - \orig_start .org . - ( \orig_end - \orig_start ) & 1 .org . - ( \orig_end - \orig_start ) + ( \alt_end - \alt_start ) diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 5debb12614ad..8a52554f49f0 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -419,7 +419,7 @@ static __always_inline bool regs_irqs_disabled(struct pt_regs *regs) static __always_inline void bpon(void) { - asm volatile(ALTERNATIVE("nop", ".insn rrf,0xb2e80000,0,0,13,0", 82)); + asm volatile(ALTERNATIVE("nop", ".insn rrf,0xb2e80000,0,0,13,0", ALT_FACILITY(82))); } #endif /* __ASSEMBLY__ */ diff --git a/arch/s390/include/asm/spinlock.h b/arch/s390/include/asm/spinlock.h index 3e43c90ff135..77d5e804af93 100644 --- a/arch/s390/include/asm/spinlock.h +++ b/arch/s390/include/asm/spinlock.h @@ -79,7 +79,7 @@ static inline void arch_spin_unlock(arch_spinlock_t *lp) typecheck(int, lp->lock); kcsan_release(); asm_inline volatile( - ALTERNATIVE("nop", ".insn rre,0xb2fa0000,7,0", 49) /* NIAI 7 */ + ALTERNATIVE("nop", ".insn rre,0xb2fa0000,7,0", ALT_FACILITY(49)) /* NIAI 7 */ " sth %1,%0\n" : "=R" (((unsigned short *) &lp->lock)[1]) : "d" (0) : "cc", "memory"); diff --git a/arch/s390/kernel/alternative.c b/arch/s390/kernel/alternative.c index 33debc2a26c9..ecabdff89bce 100644 --- a/arch/s390/kernel/alternative.c +++ b/arch/s390/kernel/alternative.c @@ -1,31 +1,33 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/module.h> + +#include <linux/uaccess.h> #include <asm/alternative.h> #include <asm/facility.h> -#include <asm/nospec-branch.h> -void __init_or_module apply_alternatives(struct alt_instr *start, - struct alt_instr *end) +void __apply_alternatives(struct alt_instr *start, struct alt_instr *end, unsigned int ctx) { - struct alt_instr *a; u8 *instr, *replacement; + struct alt_instr *a; + bool replace; /* * 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++) { + if (!(a->ctx & ctx)) + continue; + switch (a->type) { + case ALT_TYPE_FACILITY: + replace = __test_facility(a->data, alt_stfle_fac_list); + break; + default: + replace = false; + } + if (!replace) + continue; instr = (u8 *)&a->instr_offset + a->instr_offset; replacement = (u8 *)&a->repl_offset + a->repl_offset; - - if (!__test_facility(a->feature, alt_stfle_fac_list)) - continue; s390_kernel_write(instr, replacement, a->instrlen); } } - -extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; -void __init apply_alternative_instructions(void) -{ - apply_alternatives(__alt_instructions, __alt_instructions_end); -} diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 866917ff013f..90027a57a524 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -32,19 +32,19 @@ _LPP_OFFSET = __LC_LPP .macro STBEAR address - ALTERNATIVE "nop", ".insn s,0xb2010000,\address", 193 + ALTERNATIVE "nop", ".insn s,0xb2010000,\address", ALT_FACILITY(193) .endm .macro LBEAR address - ALTERNATIVE "nop", ".insn s,0xb2000000,\address", 193 + ALTERNATIVE "nop", ".insn s,0xb2000000,\address", ALT_FACILITY(193) .endm .macro LPSWEY address,lpswe - ALTERNATIVE "b \lpswe; nopr", ".insn siy,0xeb0000000071,\address,0", 193 + ALTERNATIVE "b \lpswe; nopr", ".insn siy,0xeb0000000071,\address,0", ALT_FACILITY(193) .endm .macro MBEAR reg - ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), 193 + ALTERNATIVE "brcl 0,0", __stringify(mvc __PT_LAST_BREAK(8,\reg),__LC_LAST_BREAK), ALT_FACILITY(193) .endm .macro CHECK_STACK savearea @@ -100,22 +100,22 @@ _LPP_OFFSET = __LC_LPP .endm .macro BPOFF - ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", 82 + ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,12,0", ALT_FACILITY(82) .endm .macro BPON - ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", 82 + ALTERNATIVE "nop", ".insn rrf,0xb2e80000,0,0,13,0", ALT_FACILITY(82) .endm .macro BPENTER tif_ptr,tif_mask ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .insn rrf,0xb2e80000,0,0,13,0", \ - "j .+12; nop; nop", 82 + "j .+12; nop; nop", ALT_FACILITY(82) .endm .macro BPEXIT tif_ptr,tif_mask TSTMSK \tif_ptr,\tif_mask ALTERNATIVE "jz .+8; .insn rrf,0xb2e80000,0,0,12,0", \ - "jnz .+8; .insn rrf,0xb2e80000,0,0,13,0", 82 + "jnz .+8; .insn rrf,0xb2e80000,0,0,13,0", ALT_FACILITY(82) .endm #if IS_ENABLED(CONFIG_KVM) @@ -169,7 +169,7 @@ SYM_FUNC_START(__switch_to_asm) aghi %r3,__TASK_pid mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task - ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40 + ALTERNATIVE "nop", "lpp _LPP_OFFSET", ALT_FACILITY(40) BR_EX %r14 SYM_FUNC_END(__switch_to_asm) @@ -515,7 +515,7 @@ SYM_CODE_START(mcck_int_handler) jno 0f BPON stpt __LC_EXIT_TIMER -0: ALTERNATIVE "nop", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193 +0: ALTERNATIVE "nop", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA), ALT_FACILITY(193) LBEAR 0(%r12) lmg %r11,%r15,__PT_R11(%r11) LPSWEY __LC_RETURN_MCCK_PSW,__LC_RETURN_MCCK_LPSWE @@ -551,7 +551,7 @@ SYM_CODE_START(mcck_int_handler) SYM_CODE_END(mcck_int_handler) SYM_CODE_START(restart_int_handler) - ALTERNATIVE "nop", "lpp _LPP_OFFSET", 40 + ALTERNATIVE "nop", "lpp _LPP_OFFSET", ALT_FACILITY(40) stg %r15,__LC_SAVE_AREA_RESTART TSTMSK __LC_RESTART_FLAGS,RESTART_FLAG_CTLREGS,4 jz 0f diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index 0c9a73a18826..9f86ad8fa8b4 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -75,7 +75,7 @@ static inline int arch_load_niai4(int *lock) int owner; asm_inline volatile( - ALTERNATIVE("nop", ".insn rre,0xb2fa0000,4,0", 49) /* NIAI 4 */ + ALTERNATIVE("nop", ".insn rre,0xb2fa0000,4,0", ALT_FACILITY(49)) /* NIAI 4 */ " l %0,%1\n" : "=d" (owner) : "Q" (*lock) : "memory"); return owner; @@ -86,7 +86,7 @@ static inline int arch_cmpxchg_niai8(int *lock, int old, int new) int expected = old; asm_inline volatile( - ALTERNATIVE("nop", ".insn rre,0xb2fa0000,8,0", 49) /* NIAI 8 */ + ALTERNATIVE("nop", ".insn rre,0xb2fa0000,8,0", ALT_FACILITY(49)) /* NIAI 8 */ " cs %0,%3,%1\n" : "=d" (old), "=Q" (*lock) : "0" (old), "d" (new), "Q" (*lock) |