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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen stable-4.9] xen/livepatch: Clean up arch relocation handling
commit 107401ece2057cbdfb64dfedac38636b09113df2
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Jun 13 21:17:47 2017 +0100
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Jun 26 11:19:16 2017 +0100
xen/livepatch: Clean up arch relocation handling
* Reduce symbol scope and initalisation as much as possible
* Annotate a fallthrough case in arm64
* Fix switch statement style in arm32
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> [x86 and arm32]
(cherry picked from commit bf570f593554356eb508ac2f8ffb05ebbf747c78)
Release-acked-by: Julien Grall <julien.grall@xxxxxxx>
---
xen/arch/arm/arm32/livepatch.c | 27 ++++++++++++---------------
xen/arch/arm/arm64/livepatch.c | 19 +++++++------------
xen/arch/x86/livepatch.c | 13 +++++--------
3 files changed, 24 insertions(+), 35 deletions(-)
diff --git a/xen/arch/arm/arm32/livepatch.c b/xen/arch/arm/arm32/livepatch.c
index a7fd5e2..a328179 100644
--- a/xen/arch/arm/arm32/livepatch.c
+++ b/xen/arch/arm/arm32/livepatch.c
@@ -224,21 +224,21 @@ int arch_livepatch_perform(struct livepatch_elf *elf,
const struct livepatch_elf_sec *rela,
bool use_rela)
{
- const Elf_RelA *r_a;
- const Elf_Rel *r;
- unsigned int symndx, i;
- uint32_t val;
- void *dest;
+ unsigned int i;
int rc = 0;
for ( i = 0; i < (rela->sec->sh_size / rela->sec->sh_entsize); i++ )
{
+ unsigned int symndx;
+ uint32_t val;
+ void *dest;
unsigned char type;
- s32 addend = 0;
+ s32 addend;
if ( use_rela )
{
- r_a = rela->data + i * rela->sec->sh_entsize;
+ const Elf_RelA *r_a = rela->data + i * rela->sec->sh_entsize;
+
symndx = ELF32_R_SYM(r_a->r_info);
type = ELF32_R_TYPE(r_a->r_info);
dest = base->load_addr + r_a->r_offset; /* P */
@@ -246,10 +246,12 @@ int arch_livepatch_perform(struct livepatch_elf *elf,
}
else
{
- r = rela->data + i * rela->sec->sh_entsize;
+ const Elf_Rel *r = rela->data + i * rela->sec->sh_entsize;
+
symndx = ELF32_R_SYM(r->r_info);
type = ELF32_R_TYPE(r->r_info);
dest = base->load_addr + r->r_offset; /* P */
+ addend = get_addend(type, dest);
}
if ( symndx > elf->nsym )
@@ -259,13 +261,11 @@ int arch_livepatch_perform(struct livepatch_elf *elf,
return -EINVAL;
}
- if ( !use_rela )
- addend = get_addend(type, dest);
-
val = elf->sym[symndx].sym->st_value; /* S */
rc = perform_rel(type, dest, val, addend);
- switch ( rc ) {
+ switch ( rc )
+ {
case -EOVERFLOW:
dprintk(XENLOG_ERR, LIVEPATCH "%s: Overflow in relocation %u in %s
for %s!\n",
elf->name, i, rela->name, base->name);
@@ -275,9 +275,6 @@ int arch_livepatch_perform(struct livepatch_elf *elf,
dprintk(XENLOG_ERR, LIVEPATCH "%s: Unhandled relocation #%x\n",
elf->name, type);
break;
-
- default:
- break;
}
if ( rc )
diff --git a/xen/arch/arm/arm64/livepatch.c b/xen/arch/arm/arm64/livepatch.c
index dae64f5..63929b1 100644
--- a/xen/arch/arm/arm64/livepatch.c
+++ b/xen/arch/arm/arm64/livepatch.c
@@ -241,19 +241,16 @@ 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;
- bool_t overflow_check;
+ unsigned int i;
for ( i = 0; i < (rela->sec->sh_size / rela->sec->sh_entsize); i++ )
{
+ const Elf_RelA *r = rela->data + i * rela->sec->sh_entsize;
+ unsigned int symndx = ELF64_R_SYM(r->r_info);
+ void *dest = base->load_addr + r->r_offset; /* P */
+ bool overflow_check = true;
int ovf = 0;
-
- r = rela->data + i * rela->sec->sh_entsize;
-
- symndx = ELF64_R_SYM(r->r_info);
+ uint64_t val;
if ( symndx > elf->nsym )
{
@@ -262,11 +259,8 @@ int arch_livepatch_perform_rela(struct livepatch_elf *elf,
return -EINVAL;
}
- dest = base->load_addr + r->r_offset; /* P */
val = elf->sym[symndx].sym->st_value + r->r_addend; /* S+A */
- overflow_check = true;
-
/* 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 )
@@ -403,6 +397,7 @@ int arch_livepatch_perform_rela(struct livepatch_elf *elf,
case R_AARCH64_ADR_PREL_PG_HI21_NC:
overflow_check = false;
+ /* Fallthrough. */
case R_AARCH64_ADR_PREL_PG_HI21:
ovf = reloc_insn_imm(RELOC_OP_PAGE, dest, val, 12, 21,
AARCH64_INSN_IMM_ADR);
diff --git a/xen/arch/x86/livepatch.c b/xen/arch/x86/livepatch.c
index 9663ef6..bb8aa41 100644
--- a/xen/arch/x86/livepatch.c
+++ b/xen/arch/x86/livepatch.c
@@ -151,16 +151,14 @@ 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;
- uint8_t *dest;
+ unsigned int i;
for ( i = 0; i < (rela->sec->sh_size / rela->sec->sh_entsize); i++ )
{
- r = rela->data + i * rela->sec->sh_entsize;
-
- symndx = ELF64_R_SYM(r->r_info);
+ const Elf_RelA *r = rela->data + i * rela->sec->sh_entsize;
+ unsigned int symndx = ELF64_R_SYM(r->r_info);
+ uint8_t *dest = base->load_addr + r->r_offset;
+ uint64_t val;
if ( symndx > elf->nsym )
{
@@ -169,7 +167,6 @@ int arch_livepatch_perform_rela(struct livepatch_elf *elf,
return -EINVAL;
}
- dest = base->load_addr + r->r_offset;
val = r->r_addend + elf->sym[symndx].sym->st_value;
switch ( ELF64_R_TYPE(r->r_info) )
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.9
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