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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [Very RFC PATCH 3/3] livepatch: Initial ARM32/64 support.
The initial support for ARM64 - and livepatching
works:
(XEN) livepatch: xen_hello_world: Applying 1 functions
(XEN) hi_func: Hi! (called 1 times)
(XEN) Hook executing.
(XEN) livepatch: xen_hello_world finished APPLY with rc=0
(XEN) livepatch.c:1687: livepatch: load_payload_fnc: rc=0 (p->rc=0)
(XEN) livepatch: Hello World
(XEN) 'x' pressed - Dumping all livepatch patches
(XEN) build-id: e144bafc4ee8635eee5bed8e3988b484765c46c8
(XEN) name=xen_hello_world state=APPLIED(2) 0000000000318000
(.data=0000000000319000, .rodata=000000000031a000) using 3 pages.
(XEN) xen_extra_version patch 0000000000233fac(12) with 0000000000318000
(16)
(XEN) build-id=c4b842c276be43adbe4db788598b1e11bce04dc6
(XEN) depend-on=9affa110481e8e13606c61b21e5f6a357a3c8ef9
ARM32 still has some issues.
The are some TODOs left to be done:
General:
- Bubble ALT_ORIG_PTR macro for both x86/ARM.
- Unify the ELF RELA checks - they are the same on x86/ARM[32,64].
- Makefile generating .livepatch.depends needs to ingest the
-O argument based on architecture
- Test cases should move to common/ ? [Needs Jan's Ack]
ARM32 issues:
- vm_init_type: Assertion 'is_xen_heap_mfn(ma >> PAGE_SHIFT)' failed at
xen/include/asm/mm.h:23
- Need to check R_ARM_CALL, R_ARM_JUMP24: Overflow check.
- Need to implement the rest of ELF RELA
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
RFC: Wholy cow! It works!
Cc: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
xen/arch/arm/Makefile | 14 +-
xen/arch/arm/arm32/Makefile | 2 +-
xen/arch/arm/arm32/livepatch.c | 150 ++++++++++++++++
xen/arch/arm/arm64/Makefile | 1 +
xen/arch/arm/arm64/livepatch.c | 268 +++++++++++++++++++++++++++++
xen/arch/arm/livepatch.c | 84 ++++++---
xen/arch/arm/mm.c | 5 +
xen/arch/arm/test/Makefile | 85 +++++++++
xen/arch/arm/test/xen_bye_world.c | 34 ++++
xen/arch/arm/test/xen_bye_world_func.c | 22 +++
xen/arch/arm/test/xen_hello_world.c | 69 ++++++++
xen/arch/arm/test/xen_hello_world_func.c | 26 +++
xen/arch/arm/test/xen_replace_world.c | 33 ++++
xen/arch/arm/test/xen_replace_world_func.c | 22 +++
xen/common/Kconfig | 2 +-
xen/common/livepatch.c | 12 +-
xen/include/asm-arm/current.h | 7 +
xen/include/asm-arm/mm.h | 1 +
xen/include/xen/elfstructs.h | 35 ++++
19 files changed, 842 insertions(+), 30 deletions(-)
create mode 100644 xen/arch/arm/arm32/livepatch.c
create mode 100644 xen/arch/arm/arm64/livepatch.c
create mode 100644 xen/arch/arm/test/Makefile
create mode 100644 xen/arch/arm/test/xen_bye_world.c
create mode 100644 xen/arch/arm/test/xen_bye_world_func.c
create mode 100644 xen/arch/arm/test/xen_hello_world.c
create mode 100644 xen/arch/arm/test/xen_hello_world_func.c
create mode 100644 xen/arch/arm/test/xen_replace_world.c
create mode 100644 xen/arch/arm/test/xen_replace_world_func.c
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 0a96713..95cd8af 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -66,6 +66,16 @@ endif
.PHONY: tests
tests:
+ $(MAKE) -f $(BASEDIR)/Rules.mk -C test livepatch
+
+ifdef CONFIG_LIVEPATCH
+all_symbols = --all-symbols
+ifdef CONFIG_FAST_SYMBOL_LOOKUP
+all_symbols = --all-symbols --sort-by-name
+endif
+else
+all_symbols =
+endif
$(TARGET).axf: $(TARGET)-syms
# XXX: VE model loads by VMA so instead of
@@ -93,12 +103,12 @@ $(TARGET)-syms: prelink.o xen.lds
$(BASEDIR)/common/symbols-dummy.o
$(LD) $(LDFLAGS) -T xen.lds -N prelink.o \
$(BASEDIR)/common/symbols-dummy.o -o $(@D)/.$(@F).0
$(NM) -pa --format=sysv $(@D)/.$(@F).0 \
- | $(BASEDIR)/tools/symbols --sysv --sort >$(@D)/.$(@F).0.S
+ | $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort
>$(@D)/.$(@F).0.S
$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).0.o
$(LD) $(LDFLAGS) -T xen.lds -N prelink.o \
$(@D)/.$(@F).0.o -o $(@D)/.$(@F).1
$(NM) -pa --format=sysv $(@D)/.$(@F).1 \
- | $(BASEDIR)/tools/symbols --sysv --sort >$(@D)/.$(@F).1.S
+ | $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort
>$(@D)/.$(@F).1.S
$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1.o
$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
$(@D)/.$(@F).1.o -o $@
diff --git a/xen/arch/arm/arm32/Makefile b/xen/arch/arm/arm32/Makefile
index b20db64..5966de0 100644
--- a/xen/arch/arm/arm32/Makefile
+++ b/xen/arch/arm/arm32/Makefile
@@ -4,8 +4,8 @@ obj-$(EARLY_PRINTK) += debug.o
obj-y += domctl.o
obj-y += domain.o
obj-y += entry.o
+obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-y += proc-v7.o proc-caxx.o
obj-y += smpboot.o
obj-y += traps.o
obj-y += vfp.o
-
diff --git a/xen/arch/arm/arm32/livepatch.c b/xen/arch/arm/arm32/livepatch.c
new file mode 100644
index 0000000..14a4e12
--- /dev/null
+++ b/xen/arch/arm/arm32/livepatch.c
@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include <xen/lib.h>
+#include <xen/errno.h>
+#include <xen/livepatch_elf.h>
+#include <xen/livepatch.h>
+
+void arch_livepatch_apply_jmp(struct livepatch_func *func)
+{
+}
+
+void arch_livepatch_revert_jmp(const struct livepatch_func *func)
+{
+}
+
+int arch_livepatch_verify_elf(const struct livepatch_elf *elf)
+{
+ const Elf_Ehdr *hdr = elf->hdr;
+
+ if ( hdr->e_machine != EM_ARM ||
+ hdr->e_ident[EI_CLASS] != ELFCLASS32 )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Unsupported ELF Machine type!\n",
+ elf->name);
+ return -EOPNOTSUPP;
+ }
+
+ if ( (hdr->e_flags & EF_ARM_EABI_MASK) != EF_ARM_EABI_VER5 )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Unsupported ELF EABI(%x)!\n",
+ elf->name, hdr->e_flags);
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+int arch_livepatch_perform_rel(struct livepatch_elf *elf,
+ const struct livepatch_elf_sec *base,
+ const struct livepatch_elf_sec *rela)
+{
+ return -ENOSYS;
+}
+
+int arch_livepatch_perform_rela(struct livepatch_elf *elf,
+ const struct livepatch_elf_sec *base,
+ const struct livepatch_elf_sec *rela)
+{
+ const Elf_RelA *r;
+ unsigned int symndx, i;
+ uint32_t val;
+ void *dest;
+
+
+ if ( !rela->sec->sh_size )
+ return 0;
+
+ if ( rela->sec->sh_entsize < sizeof(Elf_RelA) ||
+ rela->sec->sh_size % rela->sec->sh_entsize )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Section relative header is
corrupted!\n",
+ elf->name);
+ return -EINVAL;
+ }
+
+ for ( i = 0; i < (rela->sec->sh_size / rela->sec->sh_entsize); i++ )
+ {
+ s32 offset;
+
+ symndx = ELF32_R_SYM(r->r_info);
+ if ( symndx > elf->nsym )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Relative symbol wants symbol@%u
which is past end!\n",
+ elf->name, symndx);
+ return -EINVAL;
+ }
+
+ dest = base->load_addr + r->r_offset; /* P */
+ val = elf->sym[symndx].sym->st_value; /* S */
+
+ /* r->r_addend is computed below. */
+ switch ( ELF32_R_TYPE(r->r_info) ) {
+ case R_ARM_NONE:
+ /* ignore */
+ break;
+
+ case R_ARM_MOVW_ABS_NC:
+ /* MOVW loads 16 bits into the bottom half of a register */
+ /* ResultMask(X) = X & 0xFFFF */
+ case R_ARM_MOVT_ABS:
+ /* MOVT loads 16 bits into the top half of a register.*/
+ /* ResultMask(X)= X & 0xFFFF0000 */
+ if ( ELF32_R_TYPE(r->r_info) == R_ARM_MOVT_ABS )
+ val &= 0xFFFF0000;
+ else
+ val &= 0xFFFF;
+ /*
+ * insn[19:16] = Result_Mask(X) >> 12
+ * insn[11:0] = Result_Mask(X) & 0xFFF
+ */
+ *(u32 *)dest |= val & 0xFFF;
+ *(u32 *)dest |= (val >> 12) << 16;
+ break;
+
+ case R_ARM_ABS32: /* (S + A) | T */
+ *(u32 *)dest = val + r->r_addend;
+ break;
+
+ case R_ARM_CALL:
+ case R_ARM_JUMP24:
+ offset = *(u32 *)dest;
+ /* addend = sign_extend (insn[23:0] << 2) */
+ offset = (offset & 0x00ffffff) << 2;
+ /* (S + A) - P */
+ offset += val - (unsigned long)dest;
+ /* X & 0x03FFFFFE */
+ offset &= 0x03FFFFFE;
+ *(u32 *)dest = offset;
+ /* TODO: Check overflow. */
+ if ( 0 )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Overflow in relocation %u
in %s for %s!\n",
+ elf->name, i, rela->name, base->name);
+ return -EOVERFLOW;
+ }
+ break;
+ case R_ARM_REL32: /* ((S + A) | T) – P */
+ *(u32 *)dest = *(u32 *)dest + val - (unsigned long)dest;
+ break;
+
+ default:
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Unhandled relocation #%x\n",
+ elf->name, ELF32_R_TYPE(r->r_info));
+ return -EOPNOTSUPP;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile
index c1fa43f..149b6b3 100644
--- a/xen/arch/arm/arm64/Makefile
+++ b/xen/arch/arm/arm64/Makefile
@@ -6,6 +6,7 @@ obj-y += domctl.o
obj-y += domain.o
obj-y += entry.o
obj-y += insn.o
+obj-$(CONFIG_LIVEPATCH) += livepatch.o
obj-y += smpboot.o
obj-y += traps.o
obj-y += vfp.o
diff --git a/xen/arch/arm/arm64/livepatch.c b/xen/arch/arm/arm64/livepatch.c
new file mode 100644
index 0000000..cc2e0a1
--- /dev/null
+++ b/xen/arch/arm/arm64/livepatch.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ */
+
+#include <xen/bitops.h>
+#include <xen/errno.h>
+#include <xen/lib.h>
+#include <xen/livepatch_elf.h>
+#include <xen/livepatch.h>
+#include <xen/mm.h>
+#include <xen/vmap.h>
+#include "../livepatch.h"
+
+#include <asm/bitops.h>
+#include <asm/byteorder.h>
+#include <asm/insn.h>
+
+void arch_livepatch_apply_jmp(struct livepatch_func *func)
+{
+ uint32_t insn;
+ uint32_t *old_ptr;
+ uint32_t *new_ptr;
+
+ BUILD_BUG_ON(PATCH_INSN_SIZE > sizeof(func->opaque));
+ BUILD_BUG_ON(PATCH_INSN_SIZE != sizeof(insn));
+
+ if ( !vmap_of_xen_text )
+ return;
+
+ /* Save old one. */
+ old_ptr = func->old_addr;
+ memcpy(func->opaque, old_ptr, PATCH_INSN_SIZE);
+
+ /* Branch, no link. */
+ insn = aarch64_insn_gen_branch_imm((unsigned long)func->old_addr,
+ (unsigned long)func->new_addr);
+
+ new_ptr = func->old_addr - (void *)_start + vmap_of_xen_text;
+
+ /* PATCH! */
+ *(new_ptr) = cpu_to_le32(insn);
+
+ clean_and_invalidate_dcache_va_range(new_ptr, sizeof(*new_ptr));
+}
+
+void arch_livepatch_revert_jmp(const struct livepatch_func *func)
+{
+ uint32_t *new_ptr;
+ uint32_t insn;
+
+ memcpy(&insn, func->opaque, PATCH_INSN_SIZE);
+
+ new_ptr = (uint32_t *)func->old_addr - (u32 *)_start + vmap_of_xen_text;
+
+ /* PATCH! */
+ *(new_ptr) = cpu_to_le32(insn);
+
+ clean_and_invalidate_dcache_va_range(new_ptr, sizeof(*new_ptr));
+}
+
+int arch_livepatch_verify_elf(const struct livepatch_elf *elf)
+{
+ const Elf_Ehdr *hdr = elf->hdr;
+
+ if ( hdr->e_machine != EM_AARCH64 ||
+ hdr->e_ident[EI_CLASS] != ELFCLASS64 )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Unsupported ELF Machine type!\n",
+ elf->name);
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+int arch_livepatch_perform_rel(struct livepatch_elf *elf,
+ const struct livepatch_elf_sec *base,
+ const struct livepatch_elf_sec *rela)
+{
+ return -EOPNOTSUPP;
+}
+
+
+static int reloc_insn_imm(void *dest, u64 val, int lsb, int len,
+ enum aarch64_insn_imm_type imm_type)
+{
+ u64 imm, imm_mask;
+ s64 sval = val;
+ u32 insn = *(u32 *)dest;
+
+ /* Calculate the relocation value. */
+ sval >>= lsb;
+
+ /* Extract the value bits and shift them to bit 0. */
+ imm_mask = (BIT(lsb + len) - 1) >> lsb;
+ imm = sval & imm_mask;
+
+ /* Update the instruction's immediate field. */
+ insn = aarch64_insn_encode_immediate(imm_type, insn, imm);
+ *(u32 *)dest = insn;
+
+ /*
+ * Extract the upper value bits (including the sign bit) and
+ * shift them to bit 0.
+ */
+ sval = (s64)(sval & ~(imm_mask >> 1)) >> (len - 1);
+
+ /*
+ * Overflow has occurred if the upper bits are not all equal to
+ * the sign bit of the value.
+ */
+ if ((u64)(sval + 1) >= 2)
+ return -EOVERFLOW;
+
+ return 0;
+}
+
+int arch_livepatch_perform_rela(struct livepatch_elf *elf,
+ const struct livepatch_elf_sec *base,
+ const struct livepatch_elf_sec *rela)
+{
+ const Elf_RelA *r;
+ unsigned int symndx, i;
+ uint64_t val;
+ void *dest;
+
+ if ( !rela->sec->sh_size )
+ return 0;
+
+ if ( rela->sec->sh_entsize < sizeof(Elf_RelA) ||
+ rela->sec->sh_size % rela->sec->sh_entsize )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Section relative header is
corrupted!\n",
+ elf->name);
+ return -EINVAL;
+ }
+
+ for ( i = 0; i < (rela->sec->sh_size / rela->sec->sh_entsize); i++ )
+ {
+ int err = 0;
+
+ r = rela->data + i * rela->sec->sh_entsize;
+
+ symndx = ELF64_R_SYM(r->r_info);
+
+ if ( symndx > elf->nsym )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Relative relocation wants
symbol@%u which is past end!\n",
+ elf->name, symndx);
+ return -EINVAL;
+ }
+
+ dest = base->load_addr + r->r_offset; /* P */
+ val = elf->sym[symndx].sym->st_value + r->r_addend; /* S+A */
+
+ /* ARM64 operations at minimum are always 32-bit. */
+ if ( r->r_offset >= base->sec->sh_size ||
+ (r->r_offset + sizeof(uint32_t)) > base->sec->sh_size )
+ goto bad_offset;
+
+ dprintk(XENLOG_DEBUG, LIVEPATCH "%s: %s @%p val=%#lx, type=%ld\n",
+ elf->name, elf->sym[symndx].name, dest, val,
ELF64_R_TYPE(r->r_info));
+
+ switch ( ELF64_R_TYPE(r->r_info) ) {
+ /* Data */
+ case R_AARCH64_ABS64:
+ if ( r->r_offset + sizeof(uint64_t) > base->sec->sh_size )
+ goto bad_offset;
+ *(int64_t *)dest = val;
+ break;
+
+ case R_AARCH64_ABS32:
+ *(int32_t *)dest = val;
+ if ( (int64_t)val != *(int32_t *)dest )
+ err = -EOVERFLOW;
+ break;
+
+ case R_AARCH64_PREL64:
+ if ( r->r_offset + sizeof(uint64_t) > base->sec->sh_size )
+ goto bad_offset;
+
+ val -= (uint64_t)dest;
+ *(int64_t *)dest = val;
+ break;
+
+ case R_AARCH64_PREL32:
+ val -= (uint64_t)dest;
+ *(int32_t *)dest = val;
+ if ( (int64_t)val != *(int32_t *)dest )
+ err = -EOVERFLOW;
+ break;
+
+ /* Instructions. */
+ case R_AARCH64_ADR_PREL_LO21:
+ val -= (uint64_t)dest;
+ err = reloc_insn_imm(dest, val, 0, 21, AARCH64_INSN_IMM_ADR);
+ break;
+
+ case R_AARCH64_ADR_PREL_PG_HI21:
+ val = (val & ~0xfff) - ((u64)dest & ~0xfff);
+ err = reloc_insn_imm(dest, val, 12, 21, AARCH64_INSN_IMM_ADR);
+ break;
+
+ case R_AARCH64_LDST8_ABS_LO12_NC:
+ case R_AARCH64_ADD_ABS_LO12_NC:
+ err = reloc_insn_imm(dest, val, 0, 12, AARCH64_INSN_IMM_12);
+ if ( err == -EOVERFLOW )
+ err = 0;
+ break;
+
+ case R_AARCH64_LDST16_ABS_LO12_NC:
+ err = reloc_insn_imm(dest, val, 1, 11, AARCH64_INSN_IMM_12);
+ if ( err == -EOVERFLOW )
+ err = 0;
+ break;
+
+ case R_AARCH64_LDST32_ABS_LO12_NC:
+ err = reloc_insn_imm(dest, val, 2, 10, AARCH64_INSN_IMM_12);
+ if ( err == -EOVERFLOW )
+ err = 0;
+ break;
+
+ case R_AARCH64_LDST64_ABS_LO12_NC:
+ err = reloc_insn_imm(dest, val, 3, 9, AARCH64_INSN_IMM_12);
+ if ( err == -EOVERFLOW )
+ err = 0;
+ break;
+
+ case R_AARCH64_CONDBR19:
+ err = reloc_insn_imm(dest, val, 2, 19, AARCH64_INSN_IMM_19);
+ break;
+
+ case R_AARCH64_JUMP26:
+ case R_AARCH64_CALL26:
+ val -= (uint64_t)dest;
+ err = reloc_insn_imm(dest, val, 2, 26, AARCH64_INSN_IMM_26);
+ break;
+
+ default:
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Unhandled relocation %lu\n",
+ elf->name, ELF64_R_TYPE(r->r_info));
+ return -EOPNOTSUPP;
+ }
+
+ if ( err )
+ {
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Overflow in relocation %u in %s
for %s!\n",
+ elf->name, i, rela->name, base->name);
+ return err;
+ }
+ }
+ return 0;
+
+ bad_offset:
+ dprintk(XENLOG_ERR, LIVEPATCH "%s: Relative relocation offset is past %s
section!\n",
+ elf->name, base->name);
+ return -EINVAL;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/livepatch.c b/xen/arch/arm/livepatch.c
index aba1320..67749ed 100644
--- a/xen/arch/arm/livepatch.c
+++ b/xen/arch/arm/livepatch.c
@@ -6,66 +6,100 @@
#include <xen/lib.h>
#include <xen/livepatch_elf.h>
#include <xen/livepatch.h>
+#include <xen/vmap.h>
+#include "livepatch.h"
+
+#include <asm/mm.h>
+
+void *vmap_of_xen_text;
void arch_livepatch_quiesce(void)
{
+ mfn_t text_mfn;
+ unsigned int text_order;
+
+ if ( vmap_of_xen_text )
+ return;
+
+ text_mfn = _mfn(virt_to_mfn(_stext));
+ text_order = get_order_from_bytes(_end - _start);
+
+ /*
+ * The text section is read-only. So re-map Xen to be able to patch
+ * the code.
+ */
+ vmap_of_xen_text = __vmap(&text_mfn, 1 << text_order, 1, 1,
PAGE_HYPERVISOR,
+ VMAP_DEFAULT);
}
void arch_livepatch_revive(void)
{
+ /* Nuke the instruction cache */
+ invalidate_icache();
+
+ if ( vmap_of_xen_text )
+ vunmap(vmap_of_xen_text);
+
+ vmap_of_xen_text = NULL;
}
int arch_livepatch_verify_func(const struct livepatch_func *func)
{
- return -ENOSYS;
-}
+ /* No NOP patching yet. */
+ if ( !func->new_size )
+ return -EOPNOTSUPP;
-void arch_livepatch_apply_jmp(struct livepatch_func *func)
-{
-}
+ if ( func->old_size < PATCH_INSN_SIZE )
+ return -EINVAL;
-void arch_livepatch_revert_jmp(const struct livepatch_func *func)
-{
+ return 0;
}
void arch_livepatch_post_action(void)
{
+ /* arch_livepatch_revive has nuked the instruction cache. */
}
void arch_livepatch_mask(void)
{
+ /* TODO: No NMI on ARM? */
}
void arch_livepatch_unmask(void)
{
+ /* TODO: No NMI on ARM? */
}
-int arch_livepatch_verify_elf(const struct livepatch_elf *elf)
+int arch_livepatch_secure(const void *va, unsigned int pages, enum va_type
type)
{
- return -ENOSYS;
-}
+ unsigned long start = (unsigned long)va;
+ unsigned int flags;
-int arch_livepatch_perform_rel(struct livepatch_elf *elf,
- const struct livepatch_elf_sec *base,
- const struct livepatch_elf_sec *rela)
-{
- return -ENOSYS;
-}
+ ASSERT(va);
+ ASSERT(pages);
-int arch_livepatch_perform_rela(struct livepatch_elf *elf,
- const struct livepatch_elf_sec *base,
- const struct livepatch_elf_sec *rela)
-{
- return -ENOSYS;
-}
+ if ( type == LIVEPATCH_VA_RX )
+ flags = 0x2; /* R set,NX clear */
+ else if ( type == LIVEPATCH_VA_RW )
+ flags = 0x1; /* R clear, NX set */
+ else
+ flags = 0x3; /* R set,NX set */
-int arch_livepatch_secure(const void *va, unsigned int pages, enum va_type
type)
-{
- return -ENOSYS;
+ modify_xen_mappings(start, start + pages * PAGE_SIZE, flags);
+
+ return 0;
}
void __init arch_livepatch_init(void)
{
+ void *start, *end;
+
+ start = (void *)xen_virt_end;
+ end = (void *)FIXMAP_ADDR(0);
+
+ BUG_ON(start >= end);
+
+ vm_init_type(VMAP_XEN, start, end);
}
/*
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index eca7cdd..94b4911 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -143,6 +143,8 @@ vaddr_t xenheap_virt_end __read_mostly;
vaddr_t xenheap_virt_start __read_mostly;
#endif
+vaddr_t xen_virt_end;
+
unsigned long frametable_base_pdx __read_mostly;
unsigned long frametable_virt_end __read_mostly;
@@ -540,6 +542,9 @@ void __init setup_pagetables(unsigned long
boot_phys_offset, paddr_t xen_paddr)
/* No flush required here as page table is not hooked in yet. */
}
+ if ( i < LPAE_ENTRIES )
+ xen_virt_end = XEN_VIRT_START + (i << PAGE_SHIFT);
+
pte = pte_of_xenaddr((vaddr_t)xen_xenmap);
pte.pt.table = 1;
write_pte(xen_second + second_linear_offset(XEN_VIRT_START), pte);
diff --git a/xen/arch/arm/test/Makefile b/xen/arch/arm/test/Makefile
new file mode 100644
index 0000000..c302f6a
--- /dev/null
+++ b/xen/arch/arm/test/Makefile
@@ -0,0 +1,85 @@
+include $(XEN_ROOT)/Config.mk
+
+CODE_ADDR=$(shell nm --defined $(1) | grep $(2) | awk '{print "0x"$$1}')
+CODE_SZ=$(shell nm --defined -S $(1) | grep $(2) | awk '{ print "0x"$$2}')
+
+.PHONY: default
+
+LIVEPATCH := xen_hello_world.livepatch
+LIVEPATCH_BYE := xen_bye_world.livepatch
+LIVEPATCH_REPLACE := xen_replace_world.livepatch
+
+default: livepatch
+
+install: livepatch
+ $(INSTALL_DATA) $(LIVEPATCH) $(DESTDIR)$(DEBUG_DIR)/$(LIVEPATCH)
+ $(INSTALL_DATA) $(LIVEPATCH_BYE) $(DESTDIR)$(DEBUG_DIR)/$(LIVEPATCH_BYE)
+ $(INSTALL_DATA) $(LIVEPATCH_REPLACE)
$(DESTDIR)$(DEBUG_DIR)/$(LIVEPATCH_REPLACE)
+uninstall:
+ rm -f $(DESTDIR)$(DEBUG_DIR)/$(LIVEPATCH)
+ rm -f $(DESTDIR)$(DEBUG_DIR)/$(LIVEPATCH_BYE)
+ rm -f $(DESTDIR)$(DEBUG_DIR)/$(LIVEPATCH_REPLACE)
+
+.PHONY: clean
+clean::
+ rm -f *.o .*.o.d *.livepatch config.h
+
+#
+# To compute these values we need the binary files: xen-syms
+# and xen_hello_world_func.o to be already compiled.
+#
+.PHONY: config.h
+config.h: OLD_CODE_SZ=$(call CODE_SZ,$(BASEDIR)/xen-syms,xen_extra_version)
+config.h: NEW_CODE_SZ=$(call CODE_SZ,$<,xen_hello_world)
+config.h: xen_hello_world_func.o
+ (set -e; \
+ echo "#define NEW_CODE_SZ $(NEW_CODE_SZ)"; \
+ echo "#define OLD_CODE_SZ $(OLD_CODE_SZ)") > $@
+
+xen_hello_world.o: config.h
+
+.PHONY: $(LIVEPATCH)
+$(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o
+ $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH) $^
+
+#
+# This target is only accessible if CONFIG_LIVEPATCH is defined, which
+# depends on $(build_id_linker) being available. Hence we do not
+# need any checks.
+#
+# N.B. The reason we don't use arch/x86/note.o is that it may
+# not be built (it is for EFI builds), and that we do not have
+# the note.o.bin to muck with (as it gets deleted)
+#
+.PHONY: note.o
+note.o:
+ $(OBJCOPY) -O binary --only-section=.note.gnu.build-id
$(BASEDIR)/xen-syms $@.bin
+ $(OBJCOPY) -I binary -O elf64-littleaarch64 -B aarch64 \
+ --rename-section=.data=.livepatch.depends -S $@.bin $@
+ rm -f $@.bin
+
+#
+# Extract the build-id of the xen_hello_world.livepatch
+# (which xen_bye_world will depend on).
+#
+.PHONY: hello_world_note.o
+hello_world_note.o: $(LIVEPATCH)
+ $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $(LIVEPATCH)
$@.bin
+ $(OBJCOPY) -I binary -O elf64-littleaarch64 -B aarch64 \
+ --rename-section=.data=.livepatch.depends -S $@.bin $@
+ rm -f $@.bin
+
+xen_bye_world.o: config.h
+
+.PHONY: $(LIVEPATCH_BYE)
+$(LIVEPATCH_BYE): xen_bye_world_func.o xen_bye_world.o hello_world_note.o
+ $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_BYE) $^
+
+xen_replace_world.o: config.h
+
+.PHONY: $(LIVEPATCH_REPLACE)
+$(LIVEPATCH_REPLACE): xen_replace_world_func.o xen_replace_world.o note.o
+ $(LD) $(LDFLAGS) $(build_id_linker) -r -o $(LIVEPATCH_REPLACE) $^
+
+.PHONY: livepatch
+livepatch: $(LIVEPATCH) $(LIVEPATCH_BYE) $(LIVEPATCH_REPLACE)
diff --git a/xen/arch/arm/test/xen_bye_world.c
b/xen/arch/arm/test/xen_bye_world.c
new file mode 100644
index 0000000..b75e0b1
--- /dev/null
+++ b/xen/arch/arm/test/xen_bye_world.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ */
+
+#include "config.h"
+#include <xen/lib.h>
+#include <xen/types.h>
+#include <xen/version.h>
+#include <xen/livepatch.h>
+
+#include <public/sysctl.h>
+
+static char bye_world_patch_this_fnc[] = "xen_extra_version";
+extern const char *xen_bye_world(void);
+
+struct livepatch_func __section(".livepatch.funcs") livepatch_xen_bye_world = {
+ .version = LIVEPATCH_PAYLOAD_VERSION,
+ .name = bye_world_patch_this_fnc,
+ .new_addr = xen_bye_world,
+ .old_addr = xen_extra_version,
+ .new_size = NEW_CODE_SZ,
+ .old_size = OLD_CODE_SZ,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/test/xen_bye_world_func.c
b/xen/arch/arm/test/xen_bye_world_func.c
new file mode 100644
index 0000000..32ef341
--- /dev/null
+++ b/xen/arch/arm/test/xen_bye_world_func.c
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ */
+
+#include <xen/types.h>
+
+/* Our replacement function for xen_hello_world. */
+const char *xen_bye_world(void)
+{
+ return "Bye World!";
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/test/xen_hello_world.c
b/xen/arch/arm/test/xen_hello_world.c
new file mode 100644
index 0000000..e6a095b
--- /dev/null
+++ b/xen/arch/arm/test/xen_hello_world.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ */
+
+#include "config.h"
+#include <xen/lib.h>
+#include <xen/types.h>
+#include <xen/version.h>
+#include <xen/livepatch.h>
+#include <xen/livepatch_payload.h>
+
+#include <public/sysctl.h>
+
+static char hello_world_patch_this_fnc[] = "xen_extra_version";
+extern const char *xen_hello_world(void);
+static unsigned int cnt;
+
+static void apply_hook(void)
+{
+ printk(KERN_DEBUG "Hook executing.\n");
+}
+
+static void revert_hook(void)
+{
+ printk(KERN_DEBUG "Hook unloaded.\n");
+}
+
+static void hi_func(void)
+{
+ printk(KERN_DEBUG "%s: Hi! (called %u times)\n", __func__, ++cnt);
+};
+
+/* If we are sorted we _MUST_ be the last .livepatch.hook section. */
+static void Z_check_fnc(void)
+{
+ printk(KERN_DEBUG "%s: Hi func called %u times\n", __func__, cnt);
+ BUG_ON(cnt == 0 || cnt > 2);
+ cnt = 0; /* Otherwise if you revert, apply, revert the value will be 4! */
+}
+
+LIVEPATCH_LOAD_HOOK(apply_hook);
+LIVEPATCH_UNLOAD_HOOK(revert_hook);
+
+/* Imbalance here. Two load and three unload. */
+
+LIVEPATCH_LOAD_HOOK(hi_func);
+LIVEPATCH_UNLOAD_HOOK(hi_func);
+
+LIVEPATCH_UNLOAD_HOOK(Z_check_fnc);
+
+struct livepatch_func __section(".livepatch.funcs") livepatch_xen_hello_world
= {
+ .version = LIVEPATCH_PAYLOAD_VERSION,
+ .name = hello_world_patch_this_fnc,
+ .new_addr = xen_hello_world,
+ .old_addr = xen_extra_version,
+ .new_size = NEW_CODE_SZ,
+ .old_size = OLD_CODE_SZ,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/test/xen_hello_world_func.c
b/xen/arch/arm/test/xen_hello_world_func.c
new file mode 100644
index 0000000..6a0c440
--- /dev/null
+++ b/xen/arch/arm/test/xen_hello_world_func.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ */
+
+#include <xen/types.h>
+#include <asm/alternative.h>
+
+
+/* Our replacement function for xen_extra_version. */
+const char *xen_hello_world(void)
+{
+ asm(ALTERNATIVE("nop", "nop", 1));
+
+ return "Hello World";
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/test/xen_replace_world.c
b/xen/arch/arm/test/xen_replace_world.c
new file mode 100644
index 0000000..a2a221a
--- /dev/null
+++ b/xen/arch/arm/test/xen_replace_world.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ */
+
+#include "config.h"
+#include <xen/lib.h>
+#include <xen/types.h>
+#include <xen/livepatch.h>
+
+#include <public/sysctl.h>
+
+static char xen_replace_world_name[] = "xen_extra_version";
+extern const char *xen_replace_world(void);
+
+struct livepatch_func __section(".livepatch.funcs")
livepatch_xen_replace_world = {
+ .version = LIVEPATCH_PAYLOAD_VERSION,
+ .name = xen_replace_world_name,
+ .old_addr = 0, /* Forces the hypervisor to lookup .name */
+ .new_addr = xen_replace_world,
+ .new_size = NEW_CODE_SZ,
+ .old_size = OLD_CODE_SZ,
+};
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/test/xen_replace_world_func.c
b/xen/arch/arm/test/xen_replace_world_func.c
new file mode 100644
index 0000000..afb5cda
--- /dev/null
+++ b/xen/arch/arm/test/xen_replace_world_func.c
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2016 Oracle and/or its affiliates. All rights reserved.
+ *
+ */
+
+#include <xen/types.h>
+
+/* Our replacement function for xen_hello_world. */
+const char *xen_replace_world(void)
+{
+ return "Hello Again World!";
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 51afa24..8b4dfbc 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -222,7 +222,7 @@ endmenu
config LIVEPATCH
bool "Live patching support (TECH PREVIEW)"
default n
- depends on X86 && HAS_BUILD_ID = "y"
+ depends on HAS_BUILD_ID = "y"
---help---
Allows a running Xen hypervisor to be dynamically patched using
binary patches without rebooting. This is primarily used to binarily
diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index 88a79d8..6ffd2d0 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -618,7 +618,6 @@ static int prepare_payload(struct payload *payload,
sizeof(*region->frame[i].bugs);
}
-#ifndef CONFIG_ARM
sec = livepatch_elf_sec_by_name(elf, ".altinstructions");
if ( sec )
{
@@ -636,8 +635,14 @@ static int prepare_payload(struct payload *payload,
for ( a = start; a < end; a++ )
{
+#ifndef CONFIG_ARM
+ /* TODO: Bubble ALT_ORIG_PTR up. */
const void *instr = &a->instr_offset + a->instr_offset;
const void *replacement = &a->repl_offset + a->repl_offset;
+#else
+ const void *instr = &a->orig_offset + a->orig_offset;
+ const void *replacement = &a->alt_offset + a->alt_offset;
+#endif
if ( (instr < region->start && instr >= region->end) ||
(replacement < region->start && replacement >= region->end) )
@@ -647,9 +652,14 @@ static int prepare_payload(struct payload *payload,
return -EINVAL;
}
}
+#ifndef CONFIG_ARM
apply_alternatives_nocheck(start, end);
+#else
+ apply_alternatives(start, sec->sec->sh_size);
+#endif
}
+#ifndef CONFIG_ARM
sec = livepatch_elf_sec_by_name(elf, ".ex_table");
if ( sec )
{
diff --git a/xen/include/asm-arm/current.h b/xen/include/asm-arm/current.h
index 65c0cdf..f4fcfd6 100644
--- a/xen/include/asm-arm/current.h
+++ b/xen/include/asm-arm/current.h
@@ -33,8 +33,15 @@ static inline struct cpu_info *get_cpu_info(void)
#define guest_cpu_user_regs() (&get_cpu_info()->guest_cpu_user_regs)
+#ifdef CONFIG_LIVEPATCH
+#define switch_stack_and_jump(stack, fn) \
+ asm volatile ("mov sp,%0;" \
+ "bl check_for_livepatch_work;" \
+ "b " STR(fn) : : "r" (stack) : "memory" )
+#else
#define switch_stack_and_jump(stack, fn) \
asm volatile ("mov sp,%0; b " STR(fn) : : "r" (stack) : "memory" )
+#endif
#define reset_stack_and_jump(fn) switch_stack_and_jump(get_cpu_info(), fn)
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index 19eadd2..f3e8f7e 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -120,6 +120,7 @@ extern vaddr_t xenheap_virt_end;
extern vaddr_t xenheap_virt_start;
#endif
+extern vaddr_t xen_virt_end;
#ifdef CONFIG_ARM_32
#define is_xen_heap_page(page) is_xen_heap_mfn(page_to_mfn(page))
#define is_xen_heap_mfn(mfn) ({ \
diff --git a/xen/include/xen/elfstructs.h b/xen/include/xen/elfstructs.h
index 5f2082e..43a7060 100644
--- a/xen/include/xen/elfstructs.h
+++ b/xen/include/xen/elfstructs.h
@@ -103,6 +103,15 @@ typedef uint64_t Elf64_Xword;
(ehdr).e_ident[EI_MAG2] == ELFMAG2 && \
(ehdr).e_ident[EI_MAG3] == ELFMAG3)
+/* e_flags */
+#define EF_ARM_EABI_MASK 0xff000000
+#define EF_ARM_EABI_UNKNOWN 0x00000000
+#define EF_ARM_EABI_VER1 0x01000000
+#define EF_ARM_EABI_VER2 0x02000000
+#define EF_ARM_EABI_VER3 0x03000000
+#define EF_ARM_EABI_VER4 0x04000000
+#define EF_ARM_EABI_VER5 0x05000000
+
/* ELF Header */
typedef struct elfhdr {
unsigned char e_ident[EI_NIDENT]; /* ELF Identification */
@@ -171,6 +180,7 @@ typedef struct {
#define EM_PPC 20 /* PowerPC */
#define EM_PPC64 21 /* PowerPC 64-bit */
#define EM_ARM 40 /* Advanced RISC Machines ARM */
+#define EM_AARCH64 183
#define EM_ALPHA 41 /* DEC ALPHA */
#define EM_SPARCV9 43 /* SPARC version 9 */
#define EM_ALPHA_EXP 0x9026 /* DEC ALPHA */
@@ -359,6 +369,31 @@ typedef struct {
#define R_X86_64_PC32 2 /* PC relative 32 bit signed */
#define R_X86_64_PLT32 4 /* 32 bit PLT address */
+/*
+ * S - address of symbol.
+ * A - addend for relocation (r_addend)
+ * P - address of the dest being relocated (derieved from r_offset)
+ * NC - No check for overflow.
+ *
+ * The defines also use _PREL for PC-relative address, and _NC is No Check.
+ */
+#define R_AARCH64_ABS64 257 /* Direct 64 bit. S+A, NC*/
+#define R_AARCH64_ABS32 258 /* Direct 32 bit. S+A */
+#define R_AARCH64_PREL64 260 /* S+A-P, NC */
+#define R_AARCH64_PREL32 261 /* S+A-P */
+
+#define R_AARCH64_ADR_PREL_LO21 274 /* ADR imm, [20:0]. S+A-P */
+#define R_AARCH64_ADR_PREL_PG_HI21 275 /* ADRP imm, [32:12]. Page(S+A) -
Page(P).*/
+#define R_AARCH64_ADD_ABS_LO12_NC 277 /* ADD imm. from bits 11:0. S+A, NC
*/
+
+#define R_AARCH64_CONDBR19 280 /* Bits 20:2, S+A-P */
+#define R_AARCH64_JUMP26 282 /* Bits 27:2, S+A-P */
+#define R_AARCH64_CALL26 283 /* Bits 27:2, S+A-P */
+#define R_AARCH64_LDST16_ABS_LO12_NC 284 /* LD/ST to bits 11:1, S+A, NC */
+#define R_AARCH64_LDST32_ABS_LO12_NC 285 /* LD/ST to bits 11:2, S+A, NC */
+#define R_AARCH64_LDST64_ABS_LO12_NC 286 /* LD/ST to bits 11:3, S+A, NC */
+#define R_AARCH64_LDST8_ABS_LO12_NC 278 /* LD/ST to bits 11:0, S+A, NC */
+
/* Program Header */
typedef struct {
Elf32_Word p_type; /* segment type */
--
2.4.11
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