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-rw-r--r--arch/s390/include/asm/page.h18
-rw-r--r--arch/s390/include/asm/skey.h32
-rw-r--r--arch/s390/include/asm/uaccess.h204
-rw-r--r--arch/s390/kernel/Makefile2
-rw-r--r--arch/s390/kernel/skey.c48
-rw-r--r--arch/s390/kernel/vmlinux.lds.S7
-rw-r--r--arch/s390/lib/uaccess.c188
7 files changed, 312 insertions, 187 deletions
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index ccf6d5acc0df..9240a363c893 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -130,11 +130,19 @@ typedef pte_t *pgtable_t;
static inline void page_set_storage_key(unsigned long addr,
unsigned char skey, int mapped)
{
- if (!mapped)
- asm volatile(".insn rrf,0xb22b0000,%0,%1,8,0"
- : : "d" (skey), "a" (addr));
- else
- asm volatile("sske %0,%1" : : "d" (skey), "a" (addr));
+ if (!mapped) {
+ asm volatile(
+ " .insn rrf,0xb22b0000,%[skey],%[addr],8,0"
+ :
+ : [skey] "d" (skey), [addr] "a" (addr)
+ : "memory");
+ } else {
+ asm volatile(
+ " sske %[skey],%[addr]"
+ :
+ : [skey] "d" (skey), [addr] "a" (addr)
+ : "memory");
+ }
}
static inline unsigned char page_get_storage_key(unsigned long addr)
diff --git a/arch/s390/include/asm/skey.h b/arch/s390/include/asm/skey.h
new file mode 100644
index 000000000000..84e7cf28b712
--- /dev/null
+++ b/arch/s390/include/asm/skey.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_SKEY_H
+#define __ASM_SKEY_H
+
+#include <asm/rwonce.h>
+
+struct skey_region {
+ unsigned long start;
+ unsigned long end;
+};
+
+#define SKEY_REGION(_start, _end) \
+ stringify_in_c(.section .skey_region,"a";) \
+ stringify_in_c(.balign 8;) \
+ stringify_in_c(.quad (_start);) \
+ stringify_in_c(.quad (_end);) \
+ stringify_in_c(.previous)
+
+extern int skey_regions_initialized;
+extern struct skey_region __skey_region_start[];
+extern struct skey_region __skey_region_end[];
+
+void __skey_regions_initialize(void);
+
+static inline void skey_regions_initialize(void)
+{
+ if (READ_ONCE(skey_regions_initialized))
+ return;
+ __skey_regions_initialize();
+}
+
+#endif /* __ASM_SKEY_H */
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index a43fc88c0050..3e5b8b677057 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -473,188 +473,30 @@ do { \
void __cmpxchg_user_key_called_with_bad_pointer(void);
-#define CMPXCHG_USER_KEY_MAX_LOOPS 128
-
-static __always_inline int __cmpxchg_user_key(unsigned long address, void *uval,
- __uint128_t old, __uint128_t new,
- unsigned long key, int size)
+int __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
+ unsigned char old, unsigned char new, unsigned long key);
+int __cmpxchg_user_key2(unsigned long address, unsigned short *uval,
+ unsigned short old, unsigned short new, unsigned long key);
+int __cmpxchg_user_key4(unsigned long address, unsigned int *uval,
+ unsigned int old, unsigned int new, unsigned long key);
+int __cmpxchg_user_key8(unsigned long address, unsigned long *uval,
+ unsigned long old, unsigned long new, unsigned long key);
+int __cmpxchg_user_key16(unsigned long address, __uint128_t *uval,
+ __uint128_t old, __uint128_t new, unsigned long key);
+
+static __always_inline int _cmpxchg_user_key(unsigned long address, void *uval,
+ __uint128_t old, __uint128_t new,
+ unsigned long key, int size)
{
- bool sacf_flag;
- int rc = 0;
-
switch (size) {
- case 1: {
- unsigned int prev, shift, mask, _old, _new;
- unsigned long count;
-
- shift = (3 ^ (address & 3)) << 3;
- address ^= address & 3;
- _old = ((unsigned int)old & 0xff) << shift;
- _new = ((unsigned int)new & 0xff) << shift;
- mask = ~(0xff << shift);
- sacf_flag = enable_sacf_uaccess();
- asm_inline volatile(
- " spka 0(%[key])\n"
- " sacf 256\n"
- " llill %[count],%[max_loops]\n"
- "0: l %[prev],%[address]\n"
- "1: nr %[prev],%[mask]\n"
- " xilf %[mask],0xffffffff\n"
- " or %[new],%[prev]\n"
- " or %[prev],%[tmp]\n"
- "2: lr %[tmp],%[prev]\n"
- "3: cs %[prev],%[new],%[address]\n"
- "4: jnl 5f\n"
- " xr %[tmp],%[prev]\n"
- " xr %[new],%[tmp]\n"
- " nr %[tmp],%[mask]\n"
- " jnz 5f\n"
- " brct %[count],2b\n"
- "5: sacf 768\n"
- " spka %[default_key]\n"
- EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
- : [rc] "+&d" (rc),
- [prev] "=&d" (prev),
- [address] "+Q" (*(int *)address),
- [tmp] "+&d" (_old),
- [new] "+&d" (_new),
- [mask] "+&d" (mask),
- [count] "=a" (count)
- : [key] "%[count]" (key << 4),
- [default_key] "J" (PAGE_DEFAULT_KEY),
- [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
- : "memory", "cc");
- disable_sacf_uaccess(sacf_flag);
- *(unsigned char *)uval = prev >> shift;
- if (!count)
- rc = -EAGAIN;
- return rc;
- }
- case 2: {
- unsigned int prev, shift, mask, _old, _new;
- unsigned long count;
-
- shift = (2 ^ (address & 2)) << 3;
- address ^= address & 2;
- _old = ((unsigned int)old & 0xffff) << shift;
- _new = ((unsigned int)new & 0xffff) << shift;
- mask = ~(0xffff << shift);
- sacf_flag = enable_sacf_uaccess();
- asm_inline volatile(
- " spka 0(%[key])\n"
- " sacf 256\n"
- " llill %[count],%[max_loops]\n"
- "0: l %[prev],%[address]\n"
- "1: nr %[prev],%[mask]\n"
- " xilf %[mask],0xffffffff\n"
- " or %[new],%[prev]\n"
- " or %[prev],%[tmp]\n"
- "2: lr %[tmp],%[prev]\n"
- "3: cs %[prev],%[new],%[address]\n"
- "4: jnl 5f\n"
- " xr %[tmp],%[prev]\n"
- " xr %[new],%[tmp]\n"
- " nr %[tmp],%[mask]\n"
- " jnz 5f\n"
- " brct %[count],2b\n"
- "5: sacf 768\n"
- " spka %[default_key]\n"
- EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
- : [rc] "+&d" (rc),
- [prev] "=&d" (prev),
- [address] "+Q" (*(int *)address),
- [tmp] "+&d" (_old),
- [new] "+&d" (_new),
- [mask] "+&d" (mask),
- [count] "=a" (count)
- : [key] "%[count]" (key << 4),
- [default_key] "J" (PAGE_DEFAULT_KEY),
- [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
- : "memory", "cc");
- disable_sacf_uaccess(sacf_flag);
- *(unsigned short *)uval = prev >> shift;
- if (!count)
- rc = -EAGAIN;
- return rc;
- }
- case 4: {
- unsigned int prev = old;
-
- sacf_flag = enable_sacf_uaccess();
- asm_inline volatile(
- " spka 0(%[key])\n"
- " sacf 256\n"
- "0: cs %[prev],%[new],%[address]\n"
- "1: sacf 768\n"
- " spka %[default_key]\n"
- EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
- : [rc] "+&d" (rc),
- [prev] "+&d" (prev),
- [address] "+Q" (*(int *)address)
- : [new] "d" ((unsigned int)new),
- [key] "a" (key << 4),
- [default_key] "J" (PAGE_DEFAULT_KEY)
- : "memory", "cc");
- disable_sacf_uaccess(sacf_flag);
- *(unsigned int *)uval = prev;
- return rc;
- }
- case 8: {
- unsigned long prev = old;
-
- sacf_flag = enable_sacf_uaccess();
- asm_inline volatile(
- " spka 0(%[key])\n"
- " sacf 256\n"
- "0: csg %[prev],%[new],%[address]\n"
- "1: sacf 768\n"
- " spka %[default_key]\n"
- EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
- : [rc] "+&d" (rc),
- [prev] "+&d" (prev),
- [address] "+QS" (*(long *)address)
- : [new] "d" ((unsigned long)new),
- [key] "a" (key << 4),
- [default_key] "J" (PAGE_DEFAULT_KEY)
- : "memory", "cc");
- disable_sacf_uaccess(sacf_flag);
- *(unsigned long *)uval = prev;
- return rc;
- }
- case 16: {
- __uint128_t prev = old;
-
- sacf_flag = enable_sacf_uaccess();
- asm_inline volatile(
- " spka 0(%[key])\n"
- " sacf 256\n"
- "0: cdsg %[prev],%[new],%[address]\n"
- "1: sacf 768\n"
- " spka %[default_key]\n"
- EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev])
- EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev])
- : [rc] "+&d" (rc),
- [prev] "+&d" (prev),
- [address] "+QS" (*(__int128_t *)address)
- : [new] "d" (new),
- [key] "a" (key << 4),
- [default_key] "J" (PAGE_DEFAULT_KEY)
- : "memory", "cc");
- disable_sacf_uaccess(sacf_flag);
- *(__uint128_t *)uval = prev;
- return rc;
- }
+ case 1: return __cmpxchg_user_key1(address, uval, old, new, key);
+ case 2: return __cmpxchg_user_key2(address, uval, old, new, key);
+ case 4: return __cmpxchg_user_key4(address, uval, old, new, key);
+ case 8: return __cmpxchg_user_key8(address, uval, old, new, key);
+ case 16: return __cmpxchg_user_key16(address, uval, old, new, key);
+ default: __cmpxchg_user_key_called_with_bad_pointer();
}
- __cmpxchg_user_key_called_with_bad_pointer();
- return rc;
+ return 0;
}
/**
@@ -686,8 +528,8 @@ static __always_inline int __cmpxchg_user_key(unsigned long address, void *uval,
BUILD_BUG_ON(sizeof(*(__ptr)) != sizeof(*(__uval))); \
might_fault(); \
__chk_user_ptr(__ptr); \
- __cmpxchg_user_key((unsigned long)(__ptr), (void *)(__uval), \
- (old), (new), (key), sizeof(*(__ptr))); \
+ _cmpxchg_user_key((unsigned long)(__ptr), (void *)(__uval), \
+ (old), (new), (key), sizeof(*(__ptr))); \
})
#endif /* __S390_UACCESS_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index ea5ed6654050..eb06ff888314 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -41,7 +41,7 @@ obj-y += processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o vdso.o cpufeature.o
obj-y += sysinfo.o lgr.o os_info.o ctlreg.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
-obj-y += entry.o reipl.o kdebugfs.o alternative.o
+obj-y += entry.o reipl.o kdebugfs.o alternative.o skey.o
obj-y += nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
obj-y += smp.o text_amode31.o stacktrace.o abs_lowcore.o facility.o uv.o wti.o
obj-y += diag/
diff --git a/arch/s390/kernel/skey.c b/arch/s390/kernel/skey.c
new file mode 100644
index 000000000000..ba049fd103c2
--- /dev/null
+++ b/arch/s390/kernel/skey.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <asm/rwonce.h>
+#include <asm/page.h>
+#include <asm/skey.h>
+
+int skey_regions_initialized;
+
+static inline unsigned long load_real_address(unsigned long address)
+{
+ unsigned long real;
+
+ asm volatile(
+ " lra %[real],0(%[address])\n"
+ : [real] "=d" (real)
+ : [address] "a" (address)
+ : "cc");
+ return real;
+}
+
+/*
+ * Initialize storage keys of registered memory regions with the
+ * default key. This is useful for code which is executed with a
+ * non-default access key.
+ */
+void __skey_regions_initialize(void)
+{
+ unsigned long address, real;
+ struct skey_region *r, *end;
+
+ r = __skey_region_start;
+ end = __skey_region_end;
+ while (r < end) {
+ address = r->start & PAGE_MASK;
+ do {
+ real = load_real_address(address);
+ page_set_storage_key(real, PAGE_DEFAULT_KEY, 1);
+ address += PAGE_SIZE;
+ } while (address < r->end);
+ r++;
+ }
+ /*
+ * Make sure storage keys are initialized before
+ * skey_regions_initialized is changed.
+ */
+ barrier();
+ WRITE_ONCE(skey_regions_initialized, 1);
+}
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index ff1ddba96352..1c606dfa595d 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -71,6 +71,13 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
__end_ro_after_init = .;
+ . = ALIGN(8);
+ .skey_region_table : {
+ __skey_region_start = .;
+ KEEP(*(.skey_region))
+ __skey_region_end = .;
+ }
+
.data.rel.ro : {
*(.data.rel.ro .data.rel.ro.*)
}
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index fa7d98fa1320..1a6ba105e071 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -8,11 +8,13 @@
* Gerald Schaefer (gerald.schaefer@de.ibm.com)
*/
+#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/asm-extable.h>
#include <asm/ctlreg.h>
+#include <asm/skey.h>
#ifdef CONFIG_DEBUG_ENTRY
void debug_user_asce(int exit)
@@ -145,3 +147,189 @@ unsigned long _copy_to_user_key(void __user *to, const void *from,
return raw_copy_to_user_key(to, from, n, key);
}
EXPORT_SYMBOL(_copy_to_user_key);
+
+#define CMPXCHG_USER_KEY_MAX_LOOPS 128
+
+static nokprobe_inline int __cmpxchg_user_key_small(unsigned long address, unsigned int *uval,
+ unsigned int old, unsigned int new,
+ unsigned int mask, unsigned long key)
+{
+ unsigned long count;
+ unsigned int prev;
+ bool sacf_flag;
+ int rc = 0;
+
+ skey_regions_initialize();
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ "20: spka 0(%[key])\n"
+ " sacf 256\n"
+ " llill %[count],%[max_loops]\n"
+ "0: l %[prev],%[address]\n"
+ "1: nr %[prev],%[mask]\n"
+ " xilf %[mask],0xffffffff\n"
+ " or %[new],%[prev]\n"
+ " or %[prev],%[tmp]\n"
+ "2: lr %[tmp],%[prev]\n"
+ "3: cs %[prev],%[new],%[address]\n"
+ "4: jnl 5f\n"
+ " xr %[tmp],%[prev]\n"
+ " xr %[new],%[tmp]\n"
+ " nr %[tmp],%[mask]\n"
+ " jnz 5f\n"
+ " brct %[count],2b\n"
+ "5: sacf 768\n"
+ " spka %[default_key]\n"
+ "21:\n"
+ EX_TABLE_UA_LOAD_REG(0b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(3b, 5b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(4b, 5b, %[rc], %[prev])
+ SKEY_REGION(20b, 21b)
+ : [rc] "+&d" (rc),
+ [prev] "=&d" (prev),
+ [address] "+Q" (*(int *)address),
+ [tmp] "+&d" (old),
+ [new] "+&d" (new),
+ [mask] "+&d" (mask),
+ [count] "=a" (count)
+ : [key] "%[count]" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY),
+ [max_loops] "J" (CMPXCHG_USER_KEY_MAX_LOOPS)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *uval = prev;
+ if (!count)
+ rc = -EAGAIN;
+ return rc;
+}
+
+int __kprobes __cmpxchg_user_key1(unsigned long address, unsigned char *uval,
+ unsigned char old, unsigned char new, unsigned long key)
+{
+ unsigned int prev, shift, mask, _old, _new;
+ int rc;
+
+ shift = (3 ^ (address & 3)) << 3;
+ address ^= address & 3;
+ _old = (unsigned int)old << shift;
+ _new = (unsigned int)new << shift;
+ mask = ~(0xff << shift);
+ rc = __cmpxchg_user_key_small(address, &prev, _old, _new, mask, key);
+ *uval = prev >> shift;
+ return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key1);
+
+int __kprobes __cmpxchg_user_key2(unsigned long address, unsigned short *uval,
+ unsigned short old, unsigned short new, unsigned long key)
+{
+ unsigned int prev, shift, mask, _old, _new;
+ int rc;
+
+ shift = (2 ^ (address & 2)) << 3;
+ address ^= address & 2;
+ _old = (unsigned int)old << shift;
+ _new = (unsigned int)new << shift;
+ mask = ~(0xffff << shift);
+ rc = __cmpxchg_user_key_small(address, &prev, _old, _new, mask, key);
+ *uval = prev >> shift;
+ return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key2);
+
+int __kprobes __cmpxchg_user_key4(unsigned long address, unsigned int *uval,
+ unsigned int old, unsigned int new, unsigned long key)
+{
+ unsigned int prev = old;
+ bool sacf_flag;
+ int rc = 0;
+
+ skey_regions_initialize();
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ "20: spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: cs %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ "21:\n"
+ EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+ SKEY_REGION(20b, 21b)
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+Q" (*(int *)address)
+ : [new] "d" (new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *uval = prev;
+ return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key4);
+
+int __kprobes __cmpxchg_user_key8(unsigned long address, unsigned long *uval,
+ unsigned long old, unsigned long new, unsigned long key)
+{
+ unsigned long prev = old;
+ bool sacf_flag;
+ int rc = 0;
+
+ skey_regions_initialize();
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ "20: spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: csg %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ "21:\n"
+ EX_TABLE_UA_LOAD_REG(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REG(1b, 1b, %[rc], %[prev])
+ SKEY_REGION(20b, 21b)
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+QS" (*(long *)address)
+ : [new] "d" (new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *uval = prev;
+ return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key8);
+
+int __kprobes __cmpxchg_user_key16(unsigned long address, __uint128_t *uval,
+ __uint128_t old, __uint128_t new, unsigned long key)
+{
+ __uint128_t prev = old;
+ bool sacf_flag;
+ int rc = 0;
+
+ skey_regions_initialize();
+ sacf_flag = enable_sacf_uaccess();
+ asm_inline volatile(
+ "20: spka 0(%[key])\n"
+ " sacf 256\n"
+ "0: cdsg %[prev],%[new],%[address]\n"
+ "1: sacf 768\n"
+ " spka %[default_key]\n"
+ "21:\n"
+ EX_TABLE_UA_LOAD_REGPAIR(0b, 1b, %[rc], %[prev])
+ EX_TABLE_UA_LOAD_REGPAIR(1b, 1b, %[rc], %[prev])
+ SKEY_REGION(20b, 21b)
+ : [rc] "+&d" (rc),
+ [prev] "+&d" (prev),
+ [address] "+QS" (*(__int128_t *)address)
+ : [new] "d" (new),
+ [key] "a" (key << 4),
+ [default_key] "J" (PAGE_DEFAULT_KEY)
+ : "memory", "cc");
+ disable_sacf_uaccess(sacf_flag);
+ *uval = prev;
+ return rc;
+}
+EXPORT_SYMBOL(__cmpxchg_user_key16);
generated by cgit v1.2.3 (git 2.46.0) at 2025-12-09 19:12:04 +0000