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Date: Tue, 15 Jan 2019 14:03:13 -0500
From: Ruslan Nikolaev <nruslan_devel@...oo.com>
To: kernel-hardening@...ts.openwall.com
Cc: thgarnie@...gle.com, x86@...nel.org, kstewart@...uxfoundation.org,
gregkh@...uxfoundation.org, keescook@...omium.org
Subject: [PATCH v1 06/06]: Extending kernel support for PIC modules
Extending kernel support for PIC modules
The patch is by Hassan Nadeem and Ruslan Nikolaev. This extends
the prior PIE kernel patch (by Thomas Garnier) to also support
position-independent modules that can be placed anywhere in the
48/64-bit address space (for better KASLR).
Signed-off-by: Ruslan Nikolaev <nruslan_devel@...oo.com>
---
Makefile | 4
arch/x86/Kconfig | 12
arch/x86/Makefile | 11
arch/x86/crypto/aes-x86_64-asm_64.S | 5
arch/x86/crypto/cast5-avx-x86_64-asm_64.S | 9
arch/x86/crypto/cast6-avx-x86_64-asm_64.S | 9
arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S | 3
arch/x86/crypto/sha1-mb/sha1_mb_mgr_submit_avx2.S | 3
arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S | 3
arch/x86/crypto/sha256-mb/sha256_mb_mgr_submit_avx2.S | 3
arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S | 3
arch/x86/crypto/sha512-mb/sha512_mb_mgr_submit_avx2.S | 3
arch/x86/include/asm/alternative.h | 12
arch/x86/include/asm/arch_hweight.h | 5
arch/x86/include/asm/asm.h | 60 +++-
arch/x86/include/asm/elf.h | 5
arch/x86/include/asm/jump_label.h | 4
arch/x86/include/asm/kvm_host.h | 15 -
arch/x86/include/asm/module.h | 26 +
arch/x86/include/asm/paravirt_types.h | 9
arch/x86/include/asm/percpu.h | 2
arch/x86/include/asm/uaccess.h | 6
arch/x86/include/asm/xen/hypercall.h | 31 +-
arch/x86/kernel/ftrace.c | 14
arch/x86/kernel/module.c | 263
++++++++++++++++--
arch/x86/kernel/module.lds | 1
arch/x86/kvm/emulate.c | 1
arch/x86/tools/relocs.c | 4
scripts/Makefile.modpost | 2
scripts/recordmcount.c | 3
30 files changed, 447 insertions(+), 84 deletions(-)
diff -uprN a/arch/x86/crypto/aes-x86_64-asm_64.S
b/arch/x86/crypto/aes-x86_64-asm_64.S
--- a/arch/x86/crypto/aes-x86_64-asm_64.S 2019-01-15 11:20:45.259168260
-0500
+++ b/arch/x86/crypto/aes-x86_64-asm_64.S 2019-01-15 11:34:00.001848665
-0500
@@ -17,6 +17,7 @@
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
+#include <asm/asm.h>
#define R1 %rax
#define R1E %eax
@@ -83,11 +84,11 @@
ENDPROC(FUNC);
#define round_mov(tab_off, reg_i, reg_o) \
- leaq tab_off(%rip), RBASE; \
+ _ASM_LEA_RIP(tab_off, RBASE); \
movl (RBASE,reg_i,4), reg_o;
#define round_xor(tab_off, reg_i, reg_o) \
- leaq tab_off(%rip), RBASE; \
+ _ASM_LEA_RIP(tab_off, RBASE); \
xorl (RBASE,reg_i,4), reg_o;
#define round(TAB,OFFSET,r1,r2,r3,r4,r5,r6,r7,r8,ra,rb,rc,rd) \
diff -uprN a/arch/x86/crypto/cast5-avx-x86_64-asm_64.S
b/arch/x86/crypto/cast5-avx-x86_64-asm_64.S
--- a/arch/x86/crypto/cast5-avx-x86_64-asm_64.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/cast5-avx-x86_64-asm_64.S 2019-01-15
11:34:00.001848665 -0500
@@ -25,6 +25,7 @@
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
.file "cast5-avx-x86_64-asm_64.S"
@@ -99,17 +100,17 @@
#define lookup_32bit(src, dst, op1, op2, op3, interleave_op, il_reg) \
movzbl src ## bh, RID1d; \
- leaq s1(%rip), RID2; \
+ _ASM_LEA_RIP(s1, RID2); \
movl (RID2, RID1, 4), dst ## d; \
movzbl src ## bl, RID2d; \
- leaq s2(%rip), RID1; \
+ _ASM_LEA_RIP(s2, RID1); \
op1 (RID1, RID2, 4), dst ## d; \
shrq $16, src; \
movzbl src ## bh, RID1d; \
- leaq s3(%rip), RID2; \
+ _ASM_LEA_RIP(s3, RID2); \
op2 (RID2, RID1, 4), dst ## d; \
movzbl src ## bl, RID2d; \
- leaq s4(%rip), RID1; \
+ _ASM_LEA_RIP(s4, RID1); \
op3 (RID1, RID2, 4), dst ## d; \
interleave_op(il_reg);
diff -uprN a/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
b/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
--- a/arch/x86/crypto/cast6-avx-x86_64-asm_64.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/cast6-avx-x86_64-asm_64.S 2019-01-15
11:34:00.001848665 -0500
@@ -25,6 +25,7 @@
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "glue_helper-asm-avx.S"
.file "cast6-avx-x86_64-asm_64.S"
@@ -99,17 +100,17 @@
#define lookup_32bit(src, dst, op1, op2, op3, interleave_op, il_reg) \
movzbl src ## bh, RID1d; \
- leaq s1(%rip), RID2; \
+ _ASM_LEA_RIP(s1, RID2); \
movl (RID2, RID1, 4), dst ## d; \
movzbl src ## bl, RID2d; \
- leaq s2(%rip), RID1; \
+ _ASM_LEA_RIP(s2, RID1); \
op1 (RID1, RID2, 4), dst ## d; \
shrq $16, src; \
movzbl src ## bh, RID1d; \
- leaq s3(%rip), RID2; \
+ _ASM_LEA_RIP(s3, RID2); \
op2 (RID2, RID1, 4), dst ## d; \
movzbl src ## bl, RID2d; \
- leaq s4(%rip), RID1; \
+ _ASM_LEA_RIP(s4, RID1); \
op3 (RID1, RID2, 4), dst ## d; \
interleave_op(il_reg);
diff -uprN a/arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S
b/arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S
--- a/arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/sha1-mb/sha1_mb_mgr_flush_avx2.S 2019-01-15
11:34:00.001848665 -0500
@@ -53,6 +53,7 @@
*/
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "sha1_mb_mgr_datastruct.S"
@@ -183,7 +184,7 @@ LABEL skip_ %I
# "state" and "args" are the same address, arg1
# len is arg2
- call sha1_x8_avx2
+ _ASM_CALL(sha1_x8_avx2)
# state and idx are intact
diff -uprN a/arch/x86/crypto/sha1-mb/sha1_mb_mgr_submit_avx2.S
b/arch/x86/crypto/sha1-mb/sha1_mb_mgr_submit_avx2.S
--- a/arch/x86/crypto/sha1-mb/sha1_mb_mgr_submit_avx2.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/sha1-mb/sha1_mb_mgr_submit_avx2.S 2019-01-15
11:34:00.001848665 -0500
@@ -54,6 +54,7 @@
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "sha1_mb_mgr_datastruct.S"
@@ -163,7 +164,7 @@ start_loop:
# "state" and "args" are the same address, arg1
# len is arg2
- call sha1_x8_avx2
+ _ASM_CALL(sha1_x8_avx2)
# state and idx are intact
diff -uprN a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S
--- a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S 2019-01-15
11:34:00.001848665 -0500
@@ -52,6 +52,7 @@
*/
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "sha256_mb_mgr_datastruct.S"
.extern sha256_x8_avx2
@@ -181,7 +182,7 @@ LABEL skip_ %I
# "state" and "args" are the same address, arg1
# len is arg2
- call sha256_x8_avx2
+ _ASM_CALL(sha256_x8_avx2)
# state and idx are intact
len_is_0:
diff -uprN a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_submit_avx2.S
b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_submit_avx2.S
--- a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_submit_avx2.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_submit_avx2.S 2019-01-15
11:34:00.001848665 -0500
@@ -53,6 +53,7 @@
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "sha256_mb_mgr_datastruct.S"
.extern sha256_x8_avx2
@@ -164,7 +165,7 @@ start_loop:
# "state" and "args" are the same address, arg1
# len is arg2
- call sha256_x8_avx2
+ _ASM_CALL(sha256_x8_avx2)
# state and idx are intact
diff -uprN a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S
b/arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S
--- a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/sha512-mb/sha512_mb_mgr_flush_avx2.S 2019-01-15
11:34:00.005850530 -0500
@@ -53,6 +53,7 @@
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "sha512_mb_mgr_datastruct.S"
.extern sha512_x4_avx2
@@ -177,7 +178,7 @@ LABEL skip_ %I
# "state" and "args" are the same address, arg1
# len is arg2
- call sha512_x4_avx2
+ _ASM_CALL(sha512_x4_avx2)
# state and idx are intact
len_is_0:
diff -uprN a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_submit_avx2.S
b/arch/x86/crypto/sha512-mb/sha512_mb_mgr_submit_avx2.S
--- a/arch/x86/crypto/sha512-mb/sha512_mb_mgr_submit_avx2.S 2019-01-15
11:20:45.259168260 -0500
+++ b/arch/x86/crypto/sha512-mb/sha512_mb_mgr_submit_avx2.S 2019-01-15
11:34:00.005850530 -0500
@@ -53,6 +53,7 @@
#include <linux/linkage.h>
#include <asm/frame.h>
+#include <asm/asm.h>
#include "sha512_mb_mgr_datastruct.S"
.extern sha512_x4_avx2
@@ -167,7 +168,7 @@ start_loop:
# "state" and "args" are the same address, arg1
# len is arg2
- call sha512_x4_avx2
+ _ASM_CALL(sha512_x4_avx2)
# state and idx are intact
len_is_0:
diff -uprN a/arch/x86/include/asm/alternative.h
b/arch/x86/include/asm/alternative.h
--- a/arch/x86/include/asm/alternative.h 2019-01-15 11:20:45.263168301 -0500
+++ b/arch/x86/include/asm/alternative.h 2019-01-15 11:34:00.009852393 -0500
@@ -207,8 +207,8 @@ static inline int alternatives_text_rese
/* Like alternative_io, but for replacing a direct call with another
one. */
#define alternative_call(oldfunc, newfunc, feature, output, input...) \
- asm volatile (ALTERNATIVE("call %P[old]", "call %P[new]", feature) \
- : output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
+ asm volatile (ALTERNATIVE(_ASM_CALL(%p[old]), _ASM_CALL(%p[new]),
feature) \
+ : output : [old] "X" (oldfunc), [new] "X" (newfunc), ## input)
/*
* Like alternative_call, but there are two features and respective
functions.
@@ -218,11 +218,11 @@ static inline int alternatives_text_rese
*/
#define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2,
feature2, \
output, input...) \
- asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
- "call %P[new2]", feature2) \
+ asm volatile (ALTERNATIVE_2(_ASM_CALL(%p[old]), _ASM_CALL(%p[new1]),
feature1,\
+ _ASM_CALL(%p[new2]), feature2) \
: output, ASM_CALL_CONSTRAINT \
- : [old] "i" (oldfunc), [new1] "i" (newfunc1), \
- [new2] "i" (newfunc2), ## input)
+ : [old] "X" (oldfunc), [new1] "X" (newfunc1), \
+ [new2] "X" (newfunc2), ## input)
/*
* use this macro(s) if you need more than one output parameter
diff -uprN a/arch/x86/include/asm/arch_hweight.h
b/arch/x86/include/asm/arch_hweight.h
--- a/arch/x86/include/asm/arch_hweight.h 2019-01-15 11:20:45.263168301
-0500
+++ b/arch/x86/include/asm/arch_hweight.h 2019-01-15 11:34:00.009852393
-0500
@@ -3,6 +3,7 @@
#define _ASM_X86_HWEIGHT_H
#include <asm/cpufeatures.h>
+#include <asm/asm.h>
#ifdef CONFIG_64BIT
/* popcnt %edi, %eax */
@@ -24,7 +25,7 @@ static __always_inline unsigned int __ar
{
unsigned int res;
- asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
+ asm (ALTERNATIVE(_ASM_CALL(__sw_hweight32), POPCNT32, X86_FEATURE_POPCNT)
: "="REG_OUT (res)
: REG_IN (w));
@@ -52,7 +53,7 @@ static __always_inline unsigned long __a
{
unsigned long res;
- asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
+ asm (ALTERNATIVE(_ASM_CALL(__sw_hweight64), POPCNT64, X86_FEATURE_POPCNT)
: "="REG_OUT (res)
: REG_IN (w));
diff -uprN a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
--- a/arch/x86/include/asm/asm.h 2019-01-15 11:20:45.267168340 -0500
+++ b/arch/x86/include/asm/asm.h 2019-01-15 11:34:00.009852393 -0500
@@ -2,6 +2,42 @@
#ifndef _ASM_X86_ASM_H
#define _ASM_X86_ASM_H
+/* PIC modules require an indirection through GOT for
+ * external symbols. _ASM_CALL() for internal functions
+ * is optimized by replacing indirect calls with direct ones
+ * followed by 1-byte NOP paddings per a call site;
+ * Similarly, _ASM_LEA_RIP() is optimized by replacing MOV
+ * to LEA and is used to load symbol addresses on x86-64.
+ *
+ * If RETPOLINE is enabled, use PLT stubs instead to
+ * better optimize local calls.
+ */
+#if defined(MODULE) && defined(CONFIG_X86_PIC)
+# ifdef __ASSEMBLY__
+# define _ASM_LEA_RIP(v,a) movq v##@...PCREL(%rip), a
+# ifdef CONFIG_RETPOLINE
+# define _ASM_CALL(f) call f##@PLT
+# else
+# define _ASM_CALL(f) call *##f##@...PCREL(%rip)
+# endif
+# else
+# define _ASM_LEA_RIP(v,a) "movq " #v "@GOTPCREL(%%rip), " #a
+# ifdef CONFIG_RETPOLINE
+# define _ASM_CALL(f) "call " #f "@PLT"
+# else
+# define _ASM_CALL(f) "call *" #f "@GOTPCREL(%%rip)"
+# endif
+# endif
+#else
+# ifdef __ASSEMBLY__
+# define _ASM_CALL(f) call f
+# define _ASM_LEA_RIP(v,a) leaq v##(%rip), a
+# else
+# define _ASM_CALL(f) "call " #f
+# define _ASM_LEA_RIP(v,a) "leaq " #v "(%%rip), " #a
+# endif
+#endif
+
#ifdef __ASSEMBLY__
# define __ASM_FORM(x) x
# define __ASM_FORM_RAW(x) x
@@ -118,6 +154,24 @@
# define CC_OUT(c) [_cc_ ## c] "=qm"
#endif
+/* PLT relocations in x86_64 PIC modules are already relative.
+ * However, due to inconsistent GNU binutils behavior (e.g., i386),
+ * avoid PLT relocations in all other cases (binutils bug 23997).
+ */
+#if defined(MODULE) && defined(CONFIG_X86_PIC)
+# ifdef __ASSEMBLY__
+# define _ASM_HANDLER(x) x##@PLT
+# else
+# define _ASM_HANDLER(x) x "@PLT"
+# endif
+#else
+# ifdef __ASSEMBLY__
+# define _ASM_HANDLER(x) (x) - .
+# else
+# define _ASM_HANDLER(x) "(" x ") - ."
+# endif
+#endif
+
/* Exception table entry */
#ifdef __ASSEMBLY__
# define _ASM_EXTABLE_HANDLE(from, to, handler) \
@@ -125,7 +179,7 @@
.balign 4 ; \
.long (from) - . ; \
.long (to) - . ; \
- .long (handler) - . ; \
+ .long _ASM_HANDLER(handler); \
.popsection
# define _ASM_EXTABLE(from, to) \
@@ -171,13 +225,13 @@
.endm
#else
-# define _EXPAND_EXTABLE_HANDLE(x) #x
+# define _EXPAND_EXTABLE_HANDLE(x) _ASM_HANDLER(#x)
# define _ASM_EXTABLE_HANDLE(from, to, handler) \
" .pushsection \"__ex_table\",\"a\"\n" \
" .balign 4\n" \
" .long (" #from ") - .\n" \
" .long (" #to ") - .\n" \
- " .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n" \
+ " .long " _EXPAND_EXTABLE_HANDLE(handler) "\n" \
" .popsection\n"
# define _ASM_EXTABLE(from, to) \
diff -uprN a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
--- a/arch/x86/include/asm/elf.h 2019-01-15 11:20:45.263168301 -0500
+++ b/arch/x86/include/asm/elf.h 2019-01-15 11:34:00.009852393 -0500
@@ -63,7 +63,10 @@ typedef struct user_fxsr_struct elf_fpxr
#define R_X86_64_8 14 /* Direct 8 bit sign extended */
#define R_X86_64_PC8 15 /* 8 bit sign extended pc relative */
-#define R_X86_64_NUM 16
+#define R_X86_64_GOTPCRELX 41
+#define R_X86_64_REX_GOTPCRELX 42
+
+#define R_X86_64_NUM 43
/*
* These are used to set parameters in the core dumps.
diff -uprN a/arch/x86/include/asm/jump_label.h
b/arch/x86/include/asm/jump_label.h
--- a/arch/x86/include/asm/jump_label.h 2019-01-15 11:20:45.267168340 -0500
+++ b/arch/x86/include/asm/jump_label.h 2019-01-15 11:34:00.009852393 -0500
@@ -37,7 +37,7 @@ static __always_inline bool arch_static_
".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
".pushsection __jump_table, \"aw\" \n\t"
_ASM_ALIGN "\n\t"
- _ASM_PTR "1b, %l[l_yes], %P0 \n\t"
+ _ASM_PTR "1b, %l[l_yes], %p0 \n\t"
".popsection \n\t"
: : "X" (&((char *)key)[branch]) : : l_yes);
@@ -53,7 +53,7 @@ static __always_inline bool arch_static_
"2:\n\t"
".pushsection __jump_table, \"aw\" \n\t"
_ASM_ALIGN "\n\t"
- _ASM_PTR "1b, %l[l_yes], %P0 \n\t"
+ _ASM_PTR "1b, %l[l_yes], %p0 \n\t"
".popsection \n\t"
: : "X" (&((char *)key)[branch]) : : l_yes);
diff -uprN a/arch/x86/include/asm/kvm_host.h
b/arch/x86/include/asm/kvm_host.h
--- a/arch/x86/include/asm/kvm_host.h 2019-01-15 11:20:45.267168340 -0500
+++ b/arch/x86/include/asm/kvm_host.h 2019-01-15 11:34:00.009852393 -0500
@@ -1394,20 +1394,31 @@ enum {
*/
asmlinkage void kvm_spurious_fault(void);
+#if defined(MODULE) && defined(CONFIG_X86_PIC)
+# define ___kvm_check_rebooting \
+ "pushq %%rax \n\t" \
+ "movq kvm_rebooting@...PCREL(%%rip), %%rax \n\t" \
+ "cmpb $0, (%%rax) \n\t" \
+ "popq %%rax \n\t"
+#else
+# define ___kvm_check_rebooting \
+ "cmpb $0, kvm_rebooting" __ASM_SEL(,(%%rip)) " \n\t"
+#endif
+
#define ____kvm_handle_fault_on_reboot(insn, cleanup_insn) \
"666: " insn "\n\t" \
"668: \n\t" \
".pushsection .fixup, \"ax\" \n" \
"667: \n\t" \
cleanup_insn "\n\t" \
- "cmpb $0, kvm_rebooting" __ASM_SEL(,(%%rip)) " \n\t" \
+ ___kvm_check_rebooting \
"jne 668b \n\t" \
__ASM_SIZE(push) "$0 \n\t" \
__ASM_SIZE(push) "%%" _ASM_AX " \n\t" \
_ASM_MOVABS " $666b, %%" _ASM_AX "\n\t" \
_ASM_MOV " %%" _ASM_AX ", " __ASM_SEL(4,8) "(%%" _ASM_SP ") \n\t" \
__ASM_SIZE(pop) "%%" _ASM_AX " \n\t" \
- "call kvm_spurious_fault \n\t" \
+ _ASM_CALL(kvm_spurious_fault) " \n\t" \
".popsection \n\t" \
_ASM_EXTABLE(666b, 667b)
diff -uprN a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h
--- a/arch/x86/include/asm/module.h 2019-01-15 11:20:45.267168340 -0500
+++ b/arch/x86/include/asm/module.h 2019-01-15 11:34:00.009852393 -0500
@@ -5,13 +5,32 @@
#include <asm-generic/module.h>
#include <asm/orc_types.h>
-#ifdef CONFIG_X86_PIE
+extern const char __THUNK_FOR_PLT[];
+extern const unsigned int __THUNK_FOR_PLT_SIZE;
+
+#define PLT_ENTRY_ALIGNMENT 16
+struct plt_entry {
+#ifdef CONFIG_RETPOLINE
+ u8 mov_ins[3];
+ u32 rel_addr;
+ u8 thunk[0];
+#else
+ u16 jmp_ins;
+ u32 rel_addr;
+#endif
+} __packed __aligned(PLT_ENTRY_ALIGNMENT);
+
struct mod_got_sec {
struct elf64_shdr *got;
int got_num_entries;
int got_max_entries;
};
-#endif
+
+struct mod_plt_sec {
+ struct elf64_shdr *plt;
+ int plt_num_entries;
+ int plt_max_entries;
+};
struct mod_arch_specific {
#ifdef CONFIG_UNWINDER_ORC
@@ -19,9 +38,8 @@ struct mod_arch_specific {
int *orc_unwind_ip;
struct orc_entry *orc_unwind;
#endif
-#ifdef CONFIG_X86_PIE
struct mod_got_sec core;
-#endif
+ struct mod_plt_sec core_plt;
};
#ifdef CONFIG_X86_64
diff -uprN a/arch/x86/include/asm/paravirt_types.h
b/arch/x86/include/asm/paravirt_types.h
--- a/arch/x86/include/asm/paravirt_types.h 2019-01-15
11:20:45.263168301 -0500
+++ b/arch/x86/include/asm/paravirt_types.h 2019-01-15
11:34:00.009852393 -0500
@@ -337,7 +337,7 @@ extern struct pv_lock_ops pv_lock_ops;
#define PARAVIRT_PATCH(x) \
(offsetof(struct paravirt_patch_template, x) / sizeof(void *))
-#ifdef CONFIG_X86_PIE
+#if defined(CONFIG_X86_PIE) || (defined(MODULE) && defined(CONFIG_X86_PIC))
#define paravirt_opptr_call "a"
#define paravirt_opptr_type "p"
#else
@@ -355,7 +355,11 @@ extern struct pv_lock_ops pv_lock_ops;
* Generate some code, and mark it as patchable by the
* apply_paravirt() alternate instruction patcher.
*/
-#define _paravirt_alt(insn_string, type, clobber) \
+#if defined(MODULE) && defined(CONFIG_X86_PIC)
+# define _paravirt_alt(insn_string, type, clobber) \
+ insn_string "\n"
+#else
+# define _paravirt_alt(insn_string, type, clobber) \
"771:\n\t" insn_string "\n" "772:\n" \
".pushsection .parainstructions,\"a\"\n" \
_ASM_ALIGN "\n" \
@@ -364,6 +368,7 @@ extern struct pv_lock_ops pv_lock_ops;
" .byte 772b-771b\n" \
" .short " clobber "\n" \
".popsection\n"
+#endif
/* Generate patchable code, with the default asm parameters. */
#define paravirt_alt(insn_string) \
diff -uprN a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
--- a/arch/x86/include/asm/percpu.h 2019-01-15 11:20:45.263168301 -0500
+++ b/arch/x86/include/asm/percpu.h 2019-01-15 11:34:00.009852393 -0500
@@ -216,7 +216,7 @@ do { \
})
/* Position Independent code uses relative addresses only */
-#ifdef CONFIG_X86_PIE
+#if defined(CONFIG_X86_PIE) || (defined(MODULE) && defined(CONFIG_X86_PIC))
#define __percpu_stable_arg __percpu_arg(a1)
#else
#define __percpu_stable_arg __percpu_arg(P1)
diff -uprN a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
--- a/arch/x86/include/asm/uaccess.h 2019-01-15 11:20:45.267168340 -0500
+++ b/arch/x86/include/asm/uaccess.h 2019-01-15 11:34:00.009852393 -0500
@@ -174,7 +174,7 @@ __typeof__(__builtin_choose_expr(sizeof(
register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \
__chk_user_ptr(ptr); \
might_fault(); \
- asm volatile("call __get_user_%P4" \
+ asm volatile(_ASM_CALL(__get_user_%P4) \
: "=a" (__ret_gu), "=r" (__val_gu), \
ASM_CALL_CONSTRAINT \
: "0" (ptr), "i" (sizeof(*(ptr)))); \
@@ -183,7 +183,7 @@ __typeof__(__builtin_choose_expr(sizeof(
})
#define __put_user_x(size, x, ptr, __ret_pu) \
- asm volatile("call __put_user_" #size : "=a" (__ret_pu) \
+ asm volatile(_ASM_CALL(__put_user_##size) : "=a" (__ret_pu) \
: "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
@@ -213,7 +213,7 @@ __typeof__(__builtin_choose_expr(sizeof(
: : "A" (x), "r" (addr))
#define __put_user_x8(x, ptr, __ret_pu) \
- asm volatile("call __put_user_8" : "=a" (__ret_pu) \
+ asm volatile(_ASM_CALL(__put_user_8) : "=a" (__ret_pu) \
: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
#else
#define __put_user_asm_u64(x, ptr, retval, errret) \
diff -uprN a/arch/x86/include/asm/xen/hypercall.h
b/arch/x86/include/asm/xen/hypercall.h
--- a/arch/x86/include/asm/xen/hypercall.h 2019-01-15 11:20:45.267168340
-0500
+++ b/arch/x86/include/asm/xen/hypercall.h 2019-01-15 11:34:00.009852393
-0500
@@ -88,9 +88,24 @@ struct xen_dm_op_buf;
extern struct { char _entry[32]; } hypercall_page[];
-#define __HYPERCALL "call hypercall_page+%c[offset]"
-#define __HYPERCALL_ENTRY(x) \
+#if defined(MODULE) && defined(CONFIG_X86_PIC)
+# ifdef CONFIG_RETPOLINE
+# define HYPERCALL(x) long xen_hypercall_##x(void);
+# include <asm/xen-hypercalls.h>
+# undef HYPERCALL
+# include <asm/nospec-branch.h>
+# define __HYPERCALL(x) CALL_NOSPEC
+# define __HYPERCALL_ENTRY(x) \
+ [thunk_target] "a" (xen_hypercall_##x)
+# else
+# define __HYPERCALL(x) "call *xen_hypercall_" #x "@GOTPCREL(%%rip)"
+# define __HYPERCALL_ENTRY(x)
+# endif
+#else
+# define __HYPERCALL(x) "call hypercall_page+%c[offset]"
+# define __HYPERCALL_ENTRY(x) \
[offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
+#endif
#ifdef CONFIG_X86_32
#define __HYPERCALL_RETREG "eax"
@@ -146,7 +161,7 @@ extern struct { char _entry[32]; } hyper
({ \
__HYPERCALL_DECLS; \
__HYPERCALL_0ARG(); \
- asm volatile (__HYPERCALL \
+ asm volatile (__HYPERCALL(name) \
: __HYPERCALL_0PARAM \
: __HYPERCALL_ENTRY(name) \
: __HYPERCALL_CLOBBER0); \
@@ -157,7 +172,7 @@ extern struct { char _entry[32]; } hyper
({ \
__HYPERCALL_DECLS; \
__HYPERCALL_1ARG(a1); \
- asm volatile (__HYPERCALL \
+ asm volatile (__HYPERCALL(name) \
: __HYPERCALL_1PARAM \
: __HYPERCALL_ENTRY(name) \
: __HYPERCALL_CLOBBER1); \
@@ -168,7 +183,7 @@ extern struct { char _entry[32]; } hyper
({ \
__HYPERCALL_DECLS; \
__HYPERCALL_2ARG(a1, a2); \
- asm volatile (__HYPERCALL \
+ asm volatile (__HYPERCALL(name) \
: __HYPERCALL_2PARAM \
: __HYPERCALL_ENTRY(name) \
: __HYPERCALL_CLOBBER2); \
@@ -179,7 +194,7 @@ extern struct { char _entry[32]; } hyper
({ \
__HYPERCALL_DECLS; \
__HYPERCALL_3ARG(a1, a2, a3); \
- asm volatile (__HYPERCALL \
+ asm volatile (__HYPERCALL(name) \
: __HYPERCALL_3PARAM \
: __HYPERCALL_ENTRY(name) \
: __HYPERCALL_CLOBBER3); \
@@ -190,7 +205,7 @@ extern struct { char _entry[32]; } hyper
({ \
__HYPERCALL_DECLS; \
__HYPERCALL_4ARG(a1, a2, a3, a4); \
- asm volatile (__HYPERCALL \
+ asm volatile (__HYPERCALL(name) \
: __HYPERCALL_4PARAM \
: __HYPERCALL_ENTRY(name) \
: __HYPERCALL_CLOBBER4); \
@@ -201,7 +216,7 @@ extern struct { char _entry[32]; } hyper
({ \
__HYPERCALL_DECLS; \
__HYPERCALL_5ARG(a1, a2, a3, a4, a5); \
- asm volatile (__HYPERCALL \
+ asm volatile (__HYPERCALL(name) \
: __HYPERCALL_5PARAM \
: __HYPERCALL_ENTRY(name) \
: __HYPERCALL_CLOBBER5); \
diff -uprN a/arch/x86/Kconfig b/arch/x86/Kconfig
--- a/arch/x86/Kconfig 2019-01-15 11:20:45.259168260 -0500
+++ b/arch/x86/Kconfig 2019-01-15 11:34:00.009852393 -0500
@@ -2238,9 +2238,19 @@ config X86_PIE
select DYNAMIC_MODULE_BASE
select MODULE_REL_CRCS if MODVERSIONS
+config X86_PIC
+ bool
+ prompt "Enable PIC modules"
+ depends on X86_64
+ default y
+ select MODULE_REL_CRCS if MODVERSIONS
+ ---help---
+ Compile position-independent modules which can
+ be placed anywhere in the 64-bit address space.
+
config RANDOMIZE_BASE_LARGE
bool "Increase the randomization range of the kernel image"
- depends on X86_64 && RANDOMIZE_BASE
+ depends on X86_64 && RANDOMIZE_BASE && X86_PIC
select X86_PIE
select X86_MODULE_PLTS if MODULES
default n
diff -uprN a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
--- a/arch/x86/kernel/ftrace.c 2019-01-15 11:20:45.271168382 -0500
+++ b/arch/x86/kernel/ftrace.c 2019-01-15 11:34:00.009852393 -0500
@@ -144,13 +144,6 @@ ftrace_modify_initial_code(unsigned long
{
unsigned char replaced[MCOUNT_INSN_SIZE + 1];
- /*
- * If PIE is not enabled default to the original approach to code
- * modification.
- */
- if (!IS_ENABLED(CONFIG_X86_PIE))
- return ftrace_modify_code_direct(ip, old_code, new_code);
-
ftrace_expected = old_code;
/* Ensure the instructions point to a call to the GOT */
@@ -159,9 +152,12 @@ ftrace_modify_initial_code(unsigned long
return -EFAULT;
}
+ /*
+ * For non-PIC code, default to the original approach to code
+ * modification.
+ */
if (memcmp(replaced, got_call_preinsn, sizeof(got_call_preinsn))) {
- WARN_ONCE(1, "invalid function call");
- return -EINVAL;
+ return ftrace_modify_code_direct(ip, old_code, new_code);
}
/*
diff -uprN a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
--- a/arch/x86/kernel/module.c 2019-01-15 11:20:45.271168382 -0500
+++ b/arch/x86/kernel/module.c 2019-01-15 11:34:00.009852393 -0500
@@ -37,6 +37,9 @@
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/unwind.h>
+#include <asm/insn.h>
+
+static unsigned int module_plt_size;
#if 0
#define DEBUGP(fmt, ...) \
@@ -90,6 +93,12 @@ static u64 find_got_kernel_entry(Elf64_S
return 0;
}
+#else
+static u64 find_got_kernel_entry(Elf64_Sym *sym, const Elf64_Rela *rela)
+{
+ return 0;
+}
+#endif
static u64 module_emit_got_entry(struct module *mod, void *loc,
const Elf64_Rela *rela, Elf64_Sym *sym)
@@ -111,7 +120,7 @@ static u64 module_emit_got_entry(struct
* relocations are sorted, this will be the last entry we allocated.
* (if one exists).
*/
- if (i > 0 && got[i] == got[i - 2]) {
+ if (i > 0 && got[i] == got[i - 1]) {
ret = (u64)&got[i - 1];
} else {
gotsec->got_num_entries++;
@@ -119,7 +128,52 @@ static u64 module_emit_got_entry(struct
ret = (u64)&got[i];
}
- return ret + rela->r_addend;
+ return ret;
+}
+
+static bool plt_entries_equal(const struct plt_entry *a,
+ const struct plt_entry *b)
+{
+ void *a_val, *b_val;
+
+ a_val = (void *)a + (s64)a->rel_addr;
+ b_val = (void *)b + (s64)b->rel_addr;
+
+ return a_val == b_val;
+}
+
+static void get_plt_entry(struct plt_entry *plt_entry, struct module *mod,
+ void *loc, const Elf64_Rela *rela, Elf64_Sym *sym)
+{
+ u64 abs_val = module_emit_got_entry(mod, loc, rela, sym);
+ u32 rel_val = abs_val - (u64)&plt_entry->rel_addr
+ - sizeof(plt_entry->rel_addr);
+
+ memcpy(plt_entry, __THUNK_FOR_PLT, __THUNK_FOR_PLT_SIZE);
+ plt_entry->rel_addr = rel_val;
+}
+
+static u64 module_emit_plt_entry(struct module *mod, void *loc,
+ const Elf64_Rela *rela, Elf64_Sym *sym)
+{
+ struct mod_plt_sec *pltsec = &mod->arch.core_plt;
+ int i = pltsec->plt_num_entries;
+ void *plt = (void *)pltsec->plt->sh_addr + (u64)i * module_plt_size;
+
+ get_plt_entry(plt, mod, loc, rela, sym);
+
+ /*
+ * Check if the entry we just created is a duplicate. Given that the
+ * relocations are sorted, this will be the last entry we allocated.
+ * (if one exists).
+ */
+ if (i > 0 && plt_entries_equal(plt, plt - module_plt_size))
+ return (u64)(plt - module_plt_size);
+
+ pltsec->plt_num_entries++;
+ BUG_ON(pltsec->plt_num_entries > pltsec->plt_max_entries);
+
+ return (u64)plt;
}
#define cmp_3way(a,b) ((a) < (b) ? -1 : (a) > (b))
@@ -148,14 +202,17 @@ static bool duplicate_rel(const Elf64_Re
return num > 0 && cmp_rela(rela + num, rela + num - 1) == 0;
}
-static unsigned int count_gots(Elf64_Sym *syms, Elf64_Rela *rela, int num)
+static void count_gots_plts(unsigned long *num_got, unsigned long *num_plt,
+ Elf64_Sym *syms, Elf64_Rela *rela, int num)
{
- unsigned int ret = 0;
Elf64_Sym *s;
int i;
for (i = 0; i < num; i++) {
switch (ELF64_R_TYPE(rela[i].r_info)) {
+ case R_X86_64_PLT32:
+ case R_X86_64_REX_GOTPCRELX:
+ case R_X86_64_GOTPCRELX:
case R_X86_64_GOTPCREL:
s = syms + ELF64_R_SYM(rela[i].r_info);
@@ -164,12 +221,133 @@ static unsigned int count_gots(Elf64_Sym
* custom one for this module.
*/
if (!duplicate_rel(rela, i) &&
- !find_got_kernel_entry(s, rela + i))
- ret++;
+ !find_got_kernel_entry(s, rela + i)) {
+ (*num_got)++;
+ if (ELF64_R_TYPE(rela[i].r_info) ==
+ R_X86_64_PLT32)
+ (*num_plt)++;
+ }
break;
}
}
- return ret;
+}
+
+
+/*
+ * call *foo@...PCREL(%rip) ---> call foo nop
+ * jmp *foo@...PCREL(%rip) ---> jmp foo nop
+ */
+static int do_relax_GOTPCRELX(Elf64_Rela *rel, void *loc)
+{
+ struct insn insn;
+ void *ins_addr = loc - 2;
+
+ kernel_insn_init(&insn, ins_addr, MAX_INSN_SIZE);
+ insn_get_length(&insn);
+
+ /* 1 byte for opcode, 1 byte for modrm, 4 bytes for m32 */
+ if (insn.length != 6 || insn.opcode.value != 0xFF)
+ return -1;
+
+ switch (insn.modrm.value) {
+ case 0x15: /* CALL */
+ *(u8 *)ins_addr = 0xe8;
+ break;
+ case 0x25: /* JMP */
+ *(u8 *)ins_addr = 0xe9;
+ break;
+ default:
+ return -1;
+ }
+ memset(ins_addr + 1, 0, 4);
+ *((u8 *)ins_addr + 5) = 0x90; /* NOP */
+
+ /* Update the relocation */
+ rel->r_info &= ~ELF64_R_TYPE(~0LU);
+ rel->r_info |= R_X86_64_PC32;
+ rel->r_offset--;
+
+ return 0;
+}
+
+
+/*
+ * mov foo@...PCREL(%rip), %reg ---> lea foo(%rip), %reg
+ * */
+static int do_relax_REX_GOTPCRELX(Elf64_Rela *rel, void *loc)
+{
+ struct insn insn;
+ void *ins_addr = loc - 3;
+
+ kernel_insn_init(&insn, ins_addr, MAX_INSN_SIZE);
+ insn_get_length(&insn);
+
+ /* 1 byte for REX, 1 byte for opcode, 1 byte for modrm,
+ * 4 bytes for m32.
+ */
+ if (insn.length != 7)
+ return -1;
+
+ /* Not the MOV instruction, could be ADD, SUB etc. */
+ if (insn.opcode.value != 0x8b)
+ return 0;
+ *((u8 *)ins_addr + 1) = 0x8d; /* LEA */
+
+ /* Update the relocation. */
+ rel->r_info &= ~ELF64_R_TYPE(~0LU);
+ rel->r_info |= R_X86_64_PC32;
+
+ return 0;
+}
+
+static int apply_relaxations(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
+ struct module *mod)
+{
+ Elf64_Sym *syms = NULL;
+ int i, j;
+
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ if (sechdrs[i].sh_type == SHT_SYMTAB)
+ syms = (Elf64_Sym *)sechdrs[i].sh_addr;
+ }
+
+ if (!syms) {
+ pr_err("%s: module symtab section missing\n", mod->name);
+ return -ENOEXEC;
+ }
+
+ for (i = 0; i < ehdr->e_shnum; i++) {
+ Elf64_Rela *rels = (void *)ehdr + sechdrs[i].sh_offset;
+
+ if (sechdrs[i].sh_type != SHT_RELA)
+ continue;
+
+ for (j = 0; j < sechdrs[i].sh_size / sizeof(*rels); j++) {
+ Elf64_Rela *rel = &rels[j];
+ Elf64_Sym *sym = &syms[ELF64_R_SYM(rel->r_info)];
+ void *loc = (void *)sechdrs[sechdrs[i].sh_info].sh_addr
+ + rel->r_offset;
+
+ if (sym->st_shndx != SHN_UNDEF) {
+ /* is local symbol */
+ switch (ELF64_R_TYPE(rel->r_info)) {
+ case R_X86_64_GOTPCRELX:
+ if (do_relax_GOTPCRELX(rel, loc))
+ BUG();
+ break;
+ case R_X86_64_REX_GOTPCRELX:
+ if (do_relax_REX_GOTPCRELX(rel, loc))
+ BUG();
+ break;
+ case R_X86_64_GOTPCREL:
+ /* cannot be relaxed, ignore it */
+ break;
+ }
+ }
+ }
+ }
+
+ return 0;
}
/*
@@ -179,19 +357,25 @@ static unsigned int count_gots(Elf64_Sym
int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
char *secstrings, struct module *mod)
{
- unsigned long gots = 0;
+ unsigned long num_got = 0;
+ unsigned long num_plt = 0;
Elf_Shdr *symtab = NULL;
Elf64_Sym *syms = NULL;
char *strings, *name;
int i;
+ apply_relaxations(ehdr, sechdrs, mod);
+
/*
- * Find the empty .got section so we can expand it to store the PLT
- * entries. Record the symtab address as well.
+ * Find the empty .got and .plt sections so we can expand it
+ * to store the GOT and PLT entries.
+ * Record the symtab address as well.
*/
for (i = 0; i < ehdr->e_shnum; i++) {
if (!strcmp(secstrings + sechdrs[i].sh_name, ".got")) {
mod->arch.core.got = sechdrs + i;
+ } else if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt")) {
+ mod->arch.core_plt.plt = sechdrs + i;
} else if (sechdrs[i].sh_type == SHT_SYMTAB) {
symtab = sechdrs + i;
syms = (Elf64_Sym *)symtab->sh_addr;
@@ -202,6 +386,10 @@ int module_frob_arch_sections(Elf_Ehdr *
pr_err("%s: module GOT section missing\n", mod->name);
return -ENOEXEC;
}
+ if (!mod->arch.core_plt.plt) {
+ pr_err("%s: module PLT section missing\n", mod->name);
+ return -ENOEXEC;
+ }
if (!syms) {
pr_err("%s: module symtab section missing\n", mod->name);
return -ENOEXEC;
@@ -217,15 +405,23 @@ int module_frob_arch_sections(Elf_Ehdr *
/* sort by type, symbol index and addend */
sort(rels, numrels, sizeof(Elf64_Rela), cmp_rela, NULL);
- gots += count_gots(syms, rels, numrels);
+ count_gots_plts(&num_got, &num_plt, syms, rels, numrels);
}
mod->arch.core.got->sh_type = SHT_NOBITS;
mod->arch.core.got->sh_flags = SHF_ALLOC;
mod->arch.core.got->sh_addralign = L1_CACHE_BYTES;
- mod->arch.core.got->sh_size = (gots + 1) * sizeof(u64);
+ mod->arch.core.got->sh_size = (num_got + 1) * sizeof(u64);
mod->arch.core.got_num_entries = 0;
- mod->arch.core.got_max_entries = gots;
+ mod->arch.core.got_max_entries = num_got;
+
+ module_plt_size = ALIGN(__THUNK_FOR_PLT_SIZE, PLT_ENTRY_ALIGNMENT);
+ mod->arch.core_plt.plt->sh_type = SHT_NOBITS;
+ mod->arch.core_plt.plt->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
+ mod->arch.core_plt.plt->sh_addralign = L1_CACHE_BYTES;
+ mod->arch.core_plt.plt->sh_size = (num_plt + 1) * module_plt_size;
+ mod->arch.core_plt.plt_num_entries = 0;
+ mod->arch.core_plt.plt_max_entries = num_plt;
/*
* If a _GLOBAL_OFFSET_TABLE_ symbol exists, make it absolute for
@@ -243,7 +439,6 @@ int module_frob_arch_sections(Elf_Ehdr *
}
return 0;
}
-#endif
void *module_alloc(unsigned long size)
{
@@ -306,6 +501,23 @@ int apply_relocate(Elf32_Shdr *sechdrs,
return 0;
}
#else /*X86_64*/
+
+int check_relocation_pic_safe(Elf64_Rela *rel, Elf64_Sym *sym)
+{
+ bool isLocalSym = sym->st_shndx != SHN_UNDEF;
+
+ switch (ELF64_R_TYPE(rel->r_info)) {
+ case R_X86_64_32:
+ case R_X86_64_32S:
+ case R_X86_64_PC32:
+ if (!isLocalSym)
+ return -1;
+ break;
+ }
+
+ return 0;
+}
+
int apply_relocate_add(Elf64_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
@@ -330,6 +542,10 @@ int apply_relocate_add(Elf64_Shdr *sechd
sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+ ELF64_R_SYM(rel[i].r_info);
+#ifdef CONFIG_X86_PIC
+ BUG_ON(check_relocation_pic_safe(&rel[i], sym));
+#endif
+
DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
(int)ELF64_R_TYPE(rel[i].r_info),
sym->st_value, rel[i].r_addend, (u64)loc);
@@ -358,21 +574,30 @@ int apply_relocate_add(Elf64_Shdr *sechd
if ((s64)val != *(s32 *)loc)
goto overflow;
break;
-#ifdef CONFIG_X86_PIE
+ case R_X86_64_REX_GOTPCRELX:
+ case R_X86_64_GOTPCRELX:
case R_X86_64_GOTPCREL:
- val = module_emit_got_entry(me, loc, rel + i, sym);
+ val = module_emit_got_entry(me, loc, rel + i, sym)
+ + rel[i].r_addend;
/* fallthrough */
-#endif
case R_X86_64_PC32:
- case R_X86_64_PLT32:
if (*(u32 *)loc != 0)
goto invalid_relocation;
val -= (u64)loc;
*(u32 *)loc = val;
- if (IS_ENABLED(CONFIG_X86_PIE) &&
+ if ((IS_ENABLED(CONFIG_X86_PIE) ||
+ IS_ENABLED(CONFIG_X86_PIC)) &&
(s64)val != *(s32 *)loc)
goto overflow;
break;
+ case R_X86_64_PLT32:
+ val = module_emit_plt_entry(me, loc, rel + i, sym)
+ + rel[i].r_addend;
+ if (*(u32 *)loc != 0)
+ goto invalid_relocation;
+ val -= (u64)loc;
+ *(u32 *)loc = val;
+ break;
default:
pr_err("%s: Unknown rela relocation: %llu\n",
me->name, ELF64_R_TYPE(rel[i].r_info));
diff -uprN a/arch/x86/kernel/module.lds b/arch/x86/kernel/module.lds
--- a/arch/x86/kernel/module.lds 2019-01-15 11:20:45.271168382 -0500
+++ b/arch/x86/kernel/module.lds 2019-01-15 11:34:00.009852393 -0500
@@ -1,3 +1,4 @@
SECTIONS {
.got (NOLOAD) : { BYTE(0) }
+ .plt (NOLOAD) : { BYTE(0) }
}
diff -uprN a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
--- a/arch/x86/kvm/emulate.c 2019-01-15 11:20:45.275168421 -0500
+++ b/arch/x86/kvm/emulate.c 2019-01-15 11:34:00.013854257 -0500
@@ -428,7 +428,6 @@ static int fastop(struct x86_emulate_ctx
FOP_RET
asm(".pushsection .fixup, \"ax\"\n"
- ".global kvm_fastop_exception \n"
"kvm_fastop_exception: xor %esi, %esi; ret\n"
".popsection");
diff -uprN a/arch/x86/Makefile b/arch/x86/Makefile
--- a/arch/x86/Makefile 2019-01-15 11:20:45.259168260 -0500
+++ b/arch/x86/Makefile 2019-01-15 11:34:00.013854257 -0500
@@ -136,6 +136,17 @@ else
KBUILD_CFLAGS += $(cflags-y)
KBUILD_CFLAGS += -mno-red-zone
+
+ifdef CONFIG_X86_PIC
+ KBUILD_CFLAGS_MODULE += -fPIC -mcmodel=small
-fno-stack-protector -fvisibility=hidden
+ ifdef CONFIG_RETPOLINE
+ MOD_EXTRA_LINK += $(srctree)/arch/$(SRCARCH)/module-lib/retpoline.o
+ else
+ KBUILD_CFLAGS_MODULE += -fno-plt
+ endif
+endif
+ KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/x86/kernel/module.lds
+
ifdef CONFIG_X86_PIE
KBUILD_CFLAGS += -fPIE
KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/x86/kernel/module.lds
diff -uprN a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
--- a/arch/x86/tools/relocs.c 2019-01-15 11:20:45.279168462 -0500
+++ b/arch/x86/tools/relocs.c 2019-01-15 11:34:00.013854257 -0500
@@ -210,6 +210,8 @@ static const char *rel_type(unsigned typ
REL_TYPE(R_X86_64_JUMP_SLOT),
REL_TYPE(R_X86_64_RELATIVE),
REL_TYPE(R_X86_64_GOTPCREL),
+ REL_TYPE(R_X86_64_REX_GOTPCRELX),
+ REL_TYPE(R_X86_64_GOTPCRELX),
REL_TYPE(R_X86_64_32),
REL_TYPE(R_X86_64_32S),
REL_TYPE(R_X86_64_16),
@@ -866,6 +868,8 @@ static int do_reloc64(struct section *se
offset += per_cpu_load_addr;
switch (r_type) {
+ case R_X86_64_REX_GOTPCRELX:
+ case R_X86_64_GOTPCRELX:
case R_X86_64_GOTPCREL:
case R_X86_64_NONE:
/* NONE can be ignored. */
diff -uprN a/Makefile b/Makefile
--- a/Makefile 2019-01-15 11:20:45.087166523 -0500
+++ b/Makefile 2019-01-15 11:34:00.013854257 -0500
@@ -1207,10 +1207,10 @@ all: modules
# using awk while concatenating to the final file.
PHONY += modules
-modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
+modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux)
modules.builtin $(MOD_EXTRA_LINK)
$(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) >
$(objtree)/modules.order
@$(kecho) ' Building modules, stage 2.';
- $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
+ $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
MOD_EXTRA_LINK=$(MOD_EXTRA_LINK)
modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
$(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
diff -uprN a/scripts/Makefile.modpost b/scripts/Makefile.modpost
--- a/scripts/Makefile.modpost 2019-01-15 11:20:45.399169674 -0500
+++ b/scripts/Makefile.modpost 2019-01-15 11:34:00.013854257 -0500
@@ -125,7 +125,7 @@ quiet_cmd_ld_ko_o = LD [M] $@
-o $@ $(filter-out FORCE,$^) ; \
$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
-$(modules): %.ko :%.o %.mod.o FORCE
+$(modules): %.ko :%.o %.mod.o $(MOD_EXTRA_LINK) FORCE
+$(call if_changed,ld_ko_o)
targets += $(modules)
diff -uprN a/scripts/recordmcount.c b/scripts/recordmcount.c
--- a/scripts/recordmcount.c 2019-01-15 11:20:45.399169674 -0500
+++ b/scripts/recordmcount.c 2019-01-15 11:34:00.013854257 -0500
@@ -453,7 +453,8 @@ static int make_nop_x86(void *map, size_
/* Swap the stub and nop for a got call if the binary is built with PIE */
static int is_fake_mcount_x86_x64(Elf64_Rel const *rp)
{
- if (ELF64_R_TYPE(rp->r_info) == R_X86_64_GOTPCREL) {
+ if (ELF64_R_TYPE(rp->r_info) == R_X86_64_GOTPCREL ||
+ ELF64_R_TYPE(rp->r_info) == R_X86_64_GOTPCRELX) {
ideal_nop = ideal_nop6_x86_64;
ideal_nop_x86_size = sizeof(ideal_nop6_x86_64);
stub_x86 = stub_got_x86;
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