hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

objtool updates: 

- Improve retpoline code patching by separating it from alternatives which
    reduces memory footprint and allows to do better optimizations in the
    actual runtime patching.
 
  - Add proper retpoline support for x86/BPF
 
  - Address noinstr warnings in x86/kvm, lockdep and paravirtualization code
 
  - Add support to handle pv_opsindirect calls in the noinstr analysis
 
  - Classify symbols upfront and cache the result to avoid redundant
    str*cmp() invocations.
 
  - Add a CFI hash to reduce memory consumption which also reduces runtime
    on a allyesconfig by ~50%
 
  - Adjust XEN code to make objtool handling more robust and as a side
    effect to prevent text fragmentation due to placement of the hypercall
    page.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmF/GFgTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoc1JD/0Sz6seP2OUMxbMT3gCcFo9sMvYTdsM
 7WuGFbBbnCIo7g8JH7k0zRRBigptMp2eUtQXKkgaaIbWN4JbuVKf8KxN5/qXxLi4
 fJ12QnNTGH9N2jtzl5wKmpjaKJnnJMD9D10XwoR+T6gn6NHd+AgLEs7GxxuQUlgo
 eC9oEXhNHC8uNhiZc38EwfwmItI1bRgaLrnZWIL4rYGSMxfCK1/cEOpWrFfX9wmj
 /diB6oqMyPXZXMCtgpX7TniUr5XOTCcUkeO9mQv5bmyq/YM/8hrTbcVSJlsVYLvP
 EsBnUSHAcfLFiHXwa1RNiIGdbiPjbN+UYeXGAvqF58f3e5dTIHtN/UmWo7OH93If
 9rLMVNcMpsfPx7QRk2IxEPumLCkyfwjzfKrVDM6P6TKEIUzD1og4IK9gTlfykVsh
 56G5XiCOC/X2x8IMxKTLGuBiAVLFHXK/rSwoqhvNEWBFKDbP13QWs0LurBcW09Sa
 /kQI9pIBT1xFA/R+OY5Xy1cqNVVK1Gxmk8/bllCijA9pCFSCFM4hLZE5CevdrBCV
 h5SdqEK5hIlzFyypXfsCik/4p/+rfvlGfUKtFsPctxx29SPe+T0orx+l61jiWQok
 rZOflwMawK5lDuASHrvNHGJcWaTwoo3VcXMQDnQY0Wulc43J5IFBaPxkZzgyd+S1
 4lktHxatrCMUgw==
 =pfZi
 -----END PGP SIGNATURE-----

Merge tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Thomas Gleixner:

 - Improve retpoline code patching by separating it from alternatives
   which reduces memory footprint and allows to do better optimizations
   in the actual runtime patching.

 - Add proper retpoline support for x86/BPF

 - Address noinstr warnings in x86/kvm, lockdep and paravirtualization
   code

 - Add support to handle pv_opsindirect calls in the noinstr analysis

 - Classify symbols upfront and cache the result to avoid redundant
   str*cmp() invocations.

 - Add a CFI hash to reduce memory consumption which also reduces
   runtime on a allyesconfig by ~50%

 - Adjust XEN code to make objtool handling more robust and as a side
   effect to prevent text fragmentation due to placement of the
   hypercall page.

* tag 'objtool-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  bpf,x86: Respect X86_FEATURE_RETPOLINE*
  bpf,x86: Simplify computing label offsets
  x86,bugs: Unconditionally allow spectre_v2=retpoline,amd
  x86/alternative: Add debug prints to apply_retpolines()
  x86/alternative: Try inline spectre_v2=retpoline,amd
  x86/alternative: Handle Jcc __x86_indirect_thunk_\reg
  x86/alternative: Implement .retpoline_sites support
  x86/retpoline: Create a retpoline thunk array
  x86/retpoline: Move the retpoline thunk declarations to nospec-branch.h
  x86/asm: Fixup odd GEN-for-each-reg.h usage
  x86/asm: Fix register order
  x86/retpoline: Remove unused replacement symbols
  objtool,x86: Replace alternatives with .retpoline_sites
  objtool: Shrink struct instruction
  objtool: Explicitly avoid self modifying code in .altinstr_replacement
  objtool: Classify symbols
  objtool: Support pv_opsindirect calls for noinstr
  x86/xen: Rework the xen_{cpu,irq,mmu}_opsarrays
  x86/xen: Mark xen_force_evtchn_callback() noinstr
  x86/xen: Make irq_disable() noinstr
  ...
This commit is contained in:
Linus Torvalds 2021-11-01 13:24:43 -07:00
parent 595b28fb0c 87c87ecd00
commit 43aa0a195f
40 changed files with 1162 additions and 816 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/um/kernel/um_arch.c
View File

@ -421,6 +421,10 @@ void __init check_bugs(void)
os_check_bugs();
}
void apply_retpolines(s32 *start, s32 *end)
{
}
void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
}

14
arch/x86/include/asm/GEN-for-each-reg.h
View File

@ -1,11 +1,16 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* These are in machine order; things rely on that.
*/
#ifdef CONFIG_64BIT
GEN(rax)
GEN(rbx)
GEN(rcx)
GEN(rdx)
GEN(rbx)
GEN(rsp)
GEN(rbp)
GEN(rsi)
GEN(rdi)
GEN(rbp)
GEN(r8)
GEN(r9)
GEN(r10)
@ -16,10 +21,11 @@ GEN(r14)
GEN(r15)
#else
GEN(eax)
GEN(ebx)
GEN(ecx)
GEN(edx)
GEN(ebx)
GEN(esp)
GEN(ebp)
GEN(esi)
GEN(edi)
GEN(ebp)
#endif

1
arch/x86/include/asm/alternative.h
View File

@ -75,6 +75,7 @@ extern int alternatives_patched;
extern void alternative_instructions(void);
extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
extern void apply_retpolines(s32 *start, s32 *end);
struct module;

18
arch/x86/include/asm/asm-prototypes.h
View File

@ -17,21 +17,3 @@
extern void cmpxchg8b_emu(void);
#endif
#ifdef CONFIG_RETPOLINE
#undef GEN
#define GEN(reg) \
extern asmlinkage void __x86_indirect_thunk_ ## reg (void);
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) \
extern asmlinkage void __x86_indirect_alt_call_ ## reg (void);
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) \
extern asmlinkage void __x86_indirect_alt_jmp_ ## reg (void);
#include <asm/GEN-for-each-reg.h>
#endif /* CONFIG_RETPOLINE */

72
arch/x86/include/asm/nospec-branch.h
View File

@ -5,12 +5,15 @@
#include <linux/static_key.h>
#include <linux/objtool.h>
#include <linux/linkage.h>
#include <asm/alternative.h>
#include <asm/cpufeatures.h>
#include <asm/msr-index.h>
#include <asm/unwind_hints.h>
#define RETPOLINE_THUNK_SIZE 32
/*
* Fill the CPU return stack buffer.
*
@ -118,6 +121,16 @@
".popsection\n\t"
#ifdef CONFIG_RETPOLINE
typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
#define GEN(reg) \
extern retpoline_thunk_t __x86_indirect_thunk_ ## reg;
#include <asm/GEN-for-each-reg.h>
#undef GEN
extern retpoline_thunk_t __x86_indirect_thunk_array[];
#ifdef CONFIG_X86_64
/*
@ -303,63 +316,4 @@ static inline void mds_idle_clear_cpu_buffers(void)
#endif /* __ASSEMBLY__ */
/*
* Below is used in the eBPF JIT compiler and emits the byte sequence
* for the following assembly:
*
* With retpolines configured:
*
* callq do_rop
* spec_trap:
* pause
* lfence
* jmp spec_trap
* do_rop:
* mov %rcx,(%rsp) for x86_64
* mov %edx,(%esp) for x86_32
* retq
*
* Without retpolines configured:
*
* jmp *%rcx for x86_64
* jmp *%edx for x86_32
*/
#ifdef CONFIG_RETPOLINE
# ifdef CONFIG_X86_64
# define RETPOLINE_RCX_BPF_JIT_SIZE 17
# define RETPOLINE_RCX_BPF_JIT() \
do { \
EMIT1_off32(0xE8, 7); /* callq do_rop */ \
/* spec_trap: */ \
EMIT2(0xF3, 0x90); /* pause */ \
EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \
EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \
/* do_rop: */ \
EMIT4(0x48, 0x89, 0x0C, 0x24); /* mov %rcx,(%rsp) */ \
EMIT1(0xC3); /* retq */ \
} while (0)
# else /* !CONFIG_X86_64 */
# define RETPOLINE_EDX_BPF_JIT() \
do { \
EMIT1_off32(0xE8, 7); /* call do_rop */ \
/* spec_trap: */ \
EMIT2(0xF3, 0x90); /* pause */ \
EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \
EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \
/* do_rop: */ \
EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */ \
EMIT1(0xC3); /* ret */ \
} while (0)
# endif
#else /* !CONFIG_RETPOLINE */
# ifdef CONFIG_X86_64
# define RETPOLINE_RCX_BPF_JIT_SIZE 2
# define RETPOLINE_RCX_BPF_JIT() \
EMIT2(0xFF, 0xE1); /* jmp *%rcx */
# else /* !CONFIG_X86_64 */
# define RETPOLINE_EDX_BPF_JIT() \
EMIT2(0xFF, 0xE2) /* jmp *%edx */
# endif
#endif
#endif /* _ASM_X86_NOSPEC_BRANCH_H_ */

31
arch/x86/include/asm/paravirt.h
View File

@ -52,11 +52,11 @@ void __init paravirt_set_cap(void);
/* The paravirtualized I/O functions */
static inline void slow_down_io(void)
{
pv_ops.cpu.io_delay();
PVOP_VCALL0(cpu.io_delay);
#ifdef REALLY_SLOW_IO
pv_ops.cpu.io_delay();
pv_ops.cpu.io_delay();
pv_ops.cpu.io_delay();
PVOP_VCALL0(cpu.io_delay);
PVOP_VCALL0(cpu.io_delay);
PVOP_VCALL0(cpu.io_delay);
#endif
}
@ -113,12 +113,12 @@ static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
/*
* These special macros can be used to get or set a debugging register
*/
static inline unsigned long paravirt_get_debugreg(int reg)
static __always_inline unsigned long paravirt_get_debugreg(int reg)
{
return PVOP_CALL1(unsigned long, cpu.get_debugreg, reg);
}
#define get_debugreg(var, reg) var = paravirt_get_debugreg(reg)
static inline void set_debugreg(unsigned long val, int reg)
static __always_inline void set_debugreg(unsigned long val, int reg)
{
PVOP_VCALL2(cpu.set_debugreg, reg, val);
}
@ -133,14 +133,14 @@ static inline void write_cr0(unsigned long x)
PVOP_VCALL1(cpu.write_cr0, x);
}
static inline unsigned long read_cr2(void)
static __always_inline unsigned long read_cr2(void)
{
return PVOP_ALT_CALLEE0(unsigned long, mmu.read_cr2,
"mov %%cr2, %%rax;",
ALT_NOT(X86_FEATURE_XENPV));
}
static inline void write_cr2(unsigned long x)
static __always_inline void write_cr2(unsigned long x)
{
PVOP_VCALL1(mmu.write_cr2, x);
}
@ -653,10 +653,10 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
* functions.
*/
#define PV_THUNK_NAME(func) "__raw_callee_save_" #func
#define PV_CALLEE_SAVE_REGS_THUNK(func) \
#define __PV_CALLEE_SAVE_REGS_THUNK(func, section) \
extern typeof(func) __raw_callee_save_##func; \
\
asm(".pushsection .text;" \
asm(".pushsection " section ", \"ax\";" \
".globl " PV_THUNK_NAME(func) ";" \
".type " PV_THUNK_NAME(func) ", @function;" \
PV_THUNK_NAME(func) ":" \
@ -669,6 +669,9 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";" \
".popsection")
#define PV_CALLEE_SAVE_REGS_THUNK(func) \
__PV_CALLEE_SAVE_REGS_THUNK(func, ".text")
/* Get a reference to a callee-save function */
#define PV_CALLEE_SAVE(func) \
((struct paravirt_callee_save) { __raw_callee_save_##func })
@ -678,23 +681,23 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
((struct paravirt_callee_save) { func })
#ifdef CONFIG_PARAVIRT_XXL
static inline notrace unsigned long arch_local_save_flags(void)
static __always_inline unsigned long arch_local_save_flags(void)
{
return PVOP_ALT_CALLEE0(unsigned long, irq.save_fl, "pushf; pop %%rax;",
ALT_NOT(X86_FEATURE_XENPV));
}
static inline notrace void arch_local_irq_disable(void)
static __always_inline void arch_local_irq_disable(void)
{
PVOP_ALT_VCALLEE0(irq.irq_disable, "cli;", ALT_NOT(X86_FEATURE_XENPV));
}
static inline notrace void arch_local_irq_enable(void)
static __always_inline void arch_local_irq_enable(void)
{
PVOP_ALT_VCALLEE0(irq.irq_enable, "sti;", ALT_NOT(X86_FEATURE_XENPV));
}
static inline notrace unsigned long arch_local_irq_save(void)
static __always_inline unsigned long arch_local_irq_save(void)
{
unsigned long f;

2
arch/x86/include/asm/ptrace.h
View File

@ -181,7 +181,7 @@ static inline bool any_64bit_mode(struct pt_regs *regs)
#define current_user_stack_pointer() current_pt_regs()->sp
#define compat_user_stack_pointer() current_pt_regs()->sp
static inline bool ip_within_syscall_gap(struct pt_regs *regs)
static __always_inline bool ip_within_syscall_gap(struct pt_regs *regs)
{
bool ret = (regs->ip >= (unsigned long)entry_SYSCALL_64 &&
regs->ip < (unsigned long)entry_SYSCALL_64_safe_stack);

6
arch/x86/include/asm/xen/hypercall.h
View File

@ -308,13 +308,13 @@ HYPERVISOR_platform_op(struct xen_platform_op *op)
return _hypercall1(int, platform_op, op);
}
static inline int
static __always_inline int
HYPERVISOR_set_debugreg(int reg, unsigned long value)
{
return _hypercall2(int, set_debugreg, reg, value);
}
static inline unsigned long
static __always_inline unsigned long
HYPERVISOR_get_debugreg(int reg)
{
return _hypercall1(unsigned long, get_debugreg, reg);
@ -358,7 +358,7 @@ HYPERVISOR_event_channel_op(int cmd, void *arg)
return _hypercall2(int, event_channel_op, cmd, arg);
}
static inline int
static __always_inline int
HYPERVISOR_xen_version(int cmd, void *arg)
{
return _hypercall2(int, xen_version, cmd, arg);

191
arch/x86/kernel/alternative.c
View File

@ -29,6 +29,7 @@
#include <asm/io.h>
#include <asm/fixmap.h>
#include <asm/paravirt.h>
#include <asm/asm-prototypes.h>
int __read_mostly alternatives_patched;
@ -113,6 +114,7 @@ static void __init_or_module add_nops(void *insns, unsigned int len)
}
}
extern s32 __retpoline_sites[], __retpoline_sites_end[];
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
extern s32 __smp_locks[], __smp_locks_end[];
void text_poke_early(void *addr, const void *opcode, size_t len);
@ -221,7 +223,7 @@ static __always_inline int optimize_nops_range(u8 *instr, u8 instrlen, int off)
* "noinline" to cause control flow change and thus invalidate I$ and
* cause refetch after modification.
*/
static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *instr)
static void __init_or_module noinline optimize_nops(u8 *instr, size_t len)
{
struct insn insn;
int i = 0;
@ -239,11 +241,11 @@ static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *ins
* optimized.
*/
if (insn.length == 1 && insn.opcode.bytes[0] == 0x90)
i += optimize_nops_range(instr, a->instrlen, i);
i += optimize_nops_range(instr, len, i);
else
i += insn.length;
if (i >= a->instrlen)
if (i >= len)
return;
}
}
@ -331,10 +333,185 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
text_poke_early(instr, insn_buff, insn_buff_sz);
next:
optimize_nops(a, instr);
optimize_nops(instr, a->instrlen);
}
}
#if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION)
/*
* CALL/JMP *%\reg
*/
static int emit_indirect(int op, int reg, u8 *bytes)
{
int i = 0;
u8 modrm;
switch (op) {
case CALL_INSN_OPCODE:
modrm = 0x10; /* Reg = 2; CALL r/m */
break;
case JMP32_INSN_OPCODE:
modrm = 0x20; /* Reg = 4; JMP r/m */
break;
default:
WARN_ON_ONCE(1);
return -1;
}
if (reg >= 8) {
bytes[i++] = 0x41; /* REX.B prefix */
reg -= 8;
}
modrm |= 0xc0; /* Mod = 3 */
modrm += reg;
bytes[i++] = 0xff; /* opcode */
bytes[i++] = modrm;
return i;
}
/*
* Rewrite the compiler generated retpoline thunk calls.
*
* For spectre_v2=off (!X86_FEATURE_RETPOLINE), rewrite them into immediate
* indirect instructions, avoiding the extra indirection.
*
* For example, convert:
*
* CALL __x86_indirect_thunk_\reg
*
* into:
*
* CALL *%\reg
*
* It also tries to inline spectre_v2=retpoline,amd when size permits.
*/
static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
{
retpoline_thunk_t *target;
int reg, ret, i = 0;
u8 op, cc;
target = addr + insn->length + insn->immediate.value;
reg = target - __x86_indirect_thunk_array;
if (WARN_ON_ONCE(reg & ~0xf))
return -1;
/* If anyone ever does: CALL/JMP *%rsp, we're in deep trouble. */
BUG_ON(reg == 4);
if (cpu_feature_enabled(X86_FEATURE_RETPOLINE) &&
!cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD))
return -1;
op = insn->opcode.bytes[0];
/*
* Convert:
*
* Jcc.d32 __x86_indirect_thunk_\reg
*
* into:
*
* Jncc.d8 1f
* [ LFENCE ]
* JMP *%\reg
* [ NOP ]
* 1:
*/
/* Jcc.d32 second opcode byte is in the range: 0x80-0x8f */
if (op == 0x0f && (insn->opcode.bytes[1] & 0xf0) == 0x80) {
cc = insn->opcode.bytes[1] & 0xf;
cc ^= 1; /* invert condition */
bytes[i++] = 0x70 + cc; /* Jcc.d8 */
bytes[i++] = insn->length - 2; /* sizeof(Jcc.d8) == 2 */
/* Continue as if: JMP.d32 __x86_indirect_thunk_\reg */
op = JMP32_INSN_OPCODE;
}
/*
* For RETPOLINE_AMD: prepend the indirect CALL/JMP with an LFENCE.
*/
if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) {
bytes[i++] = 0x0f;
bytes[i++] = 0xae;
bytes[i++] = 0xe8; /* LFENCE */
}
ret = emit_indirect(op, reg, bytes + i);
if (ret < 0)
return ret;
i += ret;
for (; i < insn->length;)
bytes[i++] = BYTES_NOP1;
return i;
}
/*
* Generated by 'objtool --retpoline'.
*/
void __init_or_module noinline apply_retpolines(s32 *start, s32 *end)
{
s32 *s;
for (s = start; s < end; s++) {
void *addr = (void *)s + *s;
struct insn insn;
int len, ret;
u8 bytes[16];
u8 op1, op2;
ret = insn_decode_kernel(&insn, addr);
if (WARN_ON_ONCE(ret < 0))
continue;
op1 = insn.opcode.bytes[0];
op2 = insn.opcode.bytes[1];
switch (op1) {
case CALL_INSN_OPCODE:
case JMP32_INSN_OPCODE:
break;
case 0x0f: /* escape */
if (op2 >= 0x80 && op2 <= 0x8f)
break;
fallthrough;
default:
WARN_ON_ONCE(1);
continue;
}
DPRINTK("retpoline at: %pS (%px) len: %d to: %pS",
addr, addr, insn.length,
addr + insn.length + insn.immediate.value);
len = patch_retpoline(addr, &insn, bytes);
if (len == insn.length) {
optimize_nops(bytes, len);
DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr);
DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
text_poke_early(addr, bytes, len);
}
}
}
#else /* !RETPOLINES || !CONFIG_STACK_VALIDATION */
void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { }
#endif /* CONFIG_RETPOLINE && CONFIG_STACK_VALIDATION */
#ifdef CONFIG_SMP
static void alternatives_smp_lock(const s32 *start, const s32 *end,
u8 *text, u8 *text_end)
@ -642,6 +819,12 @@ void __init alternative_instructions(void)
*/
apply_paravirt(__parainstructions, __parainstructions_end);
/*
* Rewrite the retpolines, must be done before alternatives since
* those can rewrite the retpoline thunks.
*/
apply_retpolines(__retpoline_sites, __retpoline_sites_end);
/*
* Then patch alternatives, such that those paravirt calls that are in
* alternatives can be overwritten by their immediate fragments.

7
arch/x86/kernel/cpu/bugs.c
View File

@ -882,13 +882,6 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
return SPECTRE_V2_CMD_AUTO;
}
if (cmd == SPECTRE_V2_CMD_RETPOLINE_AMD &&
boot_cpu_data.x86_vendor != X86_VENDOR_HYGON &&
boot_cpu_data.x86_vendor != X86_VENDOR_AMD) {
pr_err("retpoline,amd selected but CPU is not AMD. Switching to AUTO select\n");
return SPECTRE_V2_CMD_AUTO;
}
spec_v2_print_cond(mitigation_options[i].option,
mitigation_options[i].secure);
return cmd;

2
arch/x86/kernel/irqflags.S
View File

@ -7,9 +7,11 @@
/*
* unsigned long native_save_fl(void)
*/
.pushsection .noinstr.text, "ax"
SYM_FUNC_START(native_save_fl)
pushf
pop %_ASM_AX
ret
SYM_FUNC_END(native_save_fl)
.popsection
EXPORT_SYMBOL(native_save_fl)

9
arch/x86/kernel/module.c
View File

@ -251,7 +251,8 @@ int module_finalize(const Elf_Ehdr *hdr,
struct module *me)
{
const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
*para = NULL, *orc = NULL, *orc_ip = NULL;
*para = NULL, *orc = NULL, *orc_ip = NULL,
*retpolines = NULL;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
@ -267,8 +268,14 @@ int module_finalize(const Elf_Ehdr *hdr,
orc = s;
if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
orc_ip = s;
if (!strcmp(".retpoline_sites", secstrings + s->sh_name))
retpolines = s;
}
if (retpolines) {
void *rseg = (void *)retpolines->sh_addr;
apply_retpolines(rseg, rseg + retpolines->sh_size);
}
if (alt) {
/* patch .altinstructions */
void *aseg = (void *)alt->sh_addr;

45
arch/x86/kernel/paravirt.c
View File

@ -218,6 +218,36 @@ void paravirt_end_context_switch(struct task_struct *next)
if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
arch_enter_lazy_mmu_mode();
}
static noinstr unsigned long pv_native_read_cr2(void)
{
return native_read_cr2();
}
static noinstr void pv_native_write_cr2(unsigned long val)
{
native_write_cr2(val);
}
static noinstr unsigned long pv_native_get_debugreg(int regno)
{
return native_get_debugreg(regno);
}
static noinstr void pv_native_set_debugreg(int regno, unsigned long val)
{
native_set_debugreg(regno, val);
}
static noinstr void pv_native_irq_enable(void)
{
native_irq_enable();
}
static noinstr void pv_native_irq_disable(void)
{
native_irq_disable();
}
#endif
enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
@ -244,8 +274,8 @@ struct paravirt_patch_template pv_ops = {
#ifdef CONFIG_PARAVIRT_XXL
.cpu.cpuid = native_cpuid,
.cpu.get_debugreg = native_get_debugreg,
.cpu.set_debugreg = native_set_debugreg,
.cpu.get_debugreg = pv_native_get_debugreg,
.cpu.set_debugreg = pv_native_set_debugreg,
.cpu.read_cr0 = native_read_cr0,
.cpu.write_cr0 = native_write_cr0,
.cpu.write_cr4 = native_write_cr4,
@ -281,8 +311,8 @@ struct paravirt_patch_template pv_ops = {
/* Irq ops. */
.irq.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
.irq.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
.irq.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
.irq.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
.irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
.irq.safe_halt = native_safe_halt,
.irq.halt = native_halt,
#endif /* CONFIG_PARAVIRT_XXL */
@ -298,8 +328,8 @@ struct paravirt_patch_template pv_ops = {
.mmu.exit_mmap = paravirt_nop,
#ifdef CONFIG_PARAVIRT_XXL
.mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2),
.mmu.write_cr2 = native_write_cr2,
.mmu.read_cr2 = __PV_IS_CALLEE_SAVE(pv_native_read_cr2),
.mmu.write_cr2 = pv_native_write_cr2,
.mmu.read_cr3 = __native_read_cr3,
.mmu.write_cr3 = native_write_cr3,
@ -371,9 +401,6 @@ struct paravirt_patch_template pv_ops = {
};
#ifdef CONFIG_PARAVIRT_XXL
/* At this point, native_get/set_debugreg has real function entries */
NOKPROBE_SYMBOL(native_get_debugreg);
NOKPROBE_SYMBOL(native_set_debugreg);
NOKPROBE_SYMBOL(native_load_idt);
void (*paravirt_iret)(void) = native_iret;

2
arch/x86/kernel/sev-shared.c
View File

@ -64,7 +64,7 @@ static bool sev_es_negotiate_protocol(void)
static __always_inline void vc_ghcb_invalidate(struct ghcb *ghcb)
{
ghcb->save.sw_exit_code = 0;
memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
__builtin_memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
}
static bool vc_decoding_needed(unsigned long exit_code)

14
arch/x86/kernel/vmlinux.lds.S
View File

@ -272,6 +272,20 @@ SECTIONS
__parainstructions_end = .;
}
#ifdef CONFIG_RETPOLINE
/*
* List of instructions that call/jmp/jcc to retpoline thunks
* __x86_indirect_thunk_*(). These instructions can be patched along
* with alternatives, after which the section can be freed.
*/
. = ALIGN(8);
.retpoline_sites : AT(ADDR(.retpoline_sites) - LOAD_OFFSET) {
__retpoline_sites = .;
*(.retpoline_sites)
__retpoline_sites_end = .;
}
#endif
/*
* struct alt_inst entries. From the header (alternative.h):
* "Alternative instructions for different CPU types or capabilities"

8
arch/x86/kvm/svm/svm.h
View File

@ -218,12 +218,12 @@ DECLARE_PER_CPU(struct svm_cpu_data *, svm_data);
void recalc_intercepts(struct vcpu_svm *svm);
static inline struct kvm_svm *to_kvm_svm(struct kvm *kvm)
static __always_inline struct kvm_svm *to_kvm_svm(struct kvm *kvm)
{
return container_of(kvm, struct kvm_svm, kvm);
}
static inline bool sev_guest(struct kvm *kvm)
static __always_inline bool sev_guest(struct kvm *kvm)
{
#ifdef CONFIG_KVM_AMD_SEV
struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
@ -234,7 +234,7 @@ static inline bool sev_guest(struct kvm *kvm)
#endif
}
static inline bool sev_es_guest(struct kvm *kvm)
static __always_inline bool sev_es_guest(struct kvm *kvm)
{
#ifdef CONFIG_KVM_AMD_SEV
struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
@ -271,7 +271,7 @@ static inline bool vmcb_is_dirty(struct vmcb *vmcb, int bit)
return !test_bit(bit, (unsigned long *)&vmcb->control.clean);
}
static inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
static __always_inline struct vcpu_svm *to_svm(struct kvm_vcpu *vcpu)
{
return container_of(vcpu, struct vcpu_svm, vcpu);
}

4
arch/x86/kvm/svm/svm_ops.h
View File

@ -56,12 +56,12 @@ static inline void invlpga(unsigned long addr, u32 asid)
* VMSAVE, VMLOAD, etc... is still controlled by the effective address size,
* hence 'unsigned long' instead of 'hpa_t'.
*/
static inline void vmsave(unsigned long pa)
static __always_inline void vmsave(unsigned long pa)
{
svm_asm1(vmsave, "a" (pa), "memory");
}
static inline void vmload(unsigned long pa)
static __always_inline void vmload(unsigned long pa)
{
svm_asm1(vmload, "a" (pa), "memory");
}

4
arch/x86/kvm/vmx/evmcs.h
View File

@ -93,7 +93,7 @@ static __always_inline int get_evmcs_offset(unsigned long field,
return evmcs_field->offset;
}
static inline void evmcs_write64(unsigned long field, u64 value)
static __always_inline void evmcs_write64(unsigned long field, u64 value)
{
u16 clean_field;
int offset = get_evmcs_offset(field, &clean_field);
@ -183,7 +183,7 @@ static inline void evmcs_load(u64 phys_addr)
__init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf);
#else /* !IS_ENABLED(CONFIG_HYPERV) */
static inline void evmcs_write64(unsigned long field, u64 value) {}
static __always_inline void evmcs_write64(unsigned long field, u64 value) {}
static inline void evmcs_write32(unsigned long field, u32 value) {}
static inline void evmcs_write16(unsigned long field, u16 value) {}
static inline u64 evmcs_read64(unsigned long field) { return 0; }

58
arch/x86/lib/retpoline.S
View File

@ -28,46 +28,14 @@
.macro THUNK reg
.align 32
SYM_FUNC_START(__x86_indirect_thunk_\reg)
.align RETPOLINE_THUNK_SIZE
SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL)
UNWIND_HINT_EMPTY
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
__stringify(RETPOLINE \reg), X86_FEATURE_RETPOLINE, \
__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD
SYM_FUNC_END(__x86_indirect_thunk_\reg)
.endm
/*
* This generates .altinstr_replacement symbols for use by objtool. They,
* however, must not actually live in .altinstr_replacement since that will be
* discarded after init, but module alternatives will also reference these
* symbols.
*
* Their names matches the "__x86_indirect_" prefix to mark them as retpolines.
*/
.macro ALT_THUNK reg
.align 1
SYM_FUNC_START_NOALIGN(__x86_indirect_alt_call_\reg)
ANNOTATE_RETPOLINE_SAFE
1: call *%\reg
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_call_\reg)
STACK_FRAME_NON_STANDARD(__x86_indirect_alt_call_\reg)
SYM_FUNC_START_NOALIGN(__x86_indirect_alt_jmp_\reg)
ANNOTATE_RETPOLINE_SAFE
1: jmp *%\reg
2: .skip 5-(2b-1b), 0x90
SYM_FUNC_END(__x86_indirect_alt_jmp_\reg)
STACK_FRAME_NON_STANDARD(__x86_indirect_alt_jmp_\reg)
.endm
/*
@ -85,22 +53,16 @@ STACK_FRAME_NON_STANDARD(__x86_indirect_alt_jmp_\reg)
#define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym)
#define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg)
#undef GEN
.align RETPOLINE_THUNK_SIZE
SYM_CODE_START(__x86_indirect_thunk_array)
#define GEN(reg) THUNK reg
#include <asm/GEN-for-each-reg.h>
#undef GEN
.align RETPOLINE_THUNK_SIZE
SYM_CODE_END(__x86_indirect_thunk_array)
#define GEN(reg) EXPORT_THUNK(reg)
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) ALT_THUNK reg
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_call_ ## reg)
#include <asm/GEN-for-each-reg.h>
#undef GEN
#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_jmp_ ## reg)
#include <asm/GEN-for-each-reg.h>

160
arch/x86/net/bpf_jit_comp.c
View File

@ -15,7 +15,6 @@
#include <asm/set_memory.h>
#include <asm/nospec-branch.h>
#include <asm/text-patching.h>
#include <asm/asm-prototypes.h>
static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
{
@ -225,6 +224,14 @@ static void jit_fill_hole(void *area, unsigned int size)
struct jit_context {
int cleanup_addr; /* Epilogue code offset */
/*
* Program specific offsets of labels in the code; these rely on the
* JIT doing at least 2 passes, recording the position on the first
* pass, only to generate the correct offset on the second pass.
*/
int tail_call_direct_label;
int tail_call_indirect_label;
};
/* Maximum number of bytes emitted while JITing one eBPF insn */
@ -380,20 +387,23 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
return __bpf_arch_text_poke(ip, t, old_addr, new_addr, true);
}
static int get_pop_bytes(bool *callee_regs_used)
#define EMIT_LFENCE() EMIT3(0x0F, 0xAE, 0xE8)
static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip)
{
int bytes = 0;
u8 *prog = *pprog;
if (callee_regs_used[3])
bytes += 2;
if (callee_regs_used[2])
bytes += 2;
if (callee_regs_used[1])
bytes += 2;
if (callee_regs_used[0])
bytes += 1;
#ifdef CONFIG_RETPOLINE
if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_AMD)) {
EMIT_LFENCE();
EMIT2(0xFF, 0xE0 + reg);
} else if (cpu_feature_enabled(X86_FEATURE_RETPOLINE)) {
emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip);
} else
#endif
EMIT2(0xFF, 0xE0 + reg);
return bytes;
*pprog = prog;
}
/*
@ -411,29 +421,12 @@ static int get_pop_bytes(bool *callee_regs_used)
* out:
*/
static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
u32 stack_depth)
u32 stack_depth, u8 *ip,
struct jit_context *ctx)
{
int tcc_off = -4 - round_up(stack_depth, 8);
u8 *prog = *pprog;
int pop_bytes = 0;
int off1 = 42;
int off2 = 31;
int off3 = 9;
/* count the additional bytes used for popping callee regs from stack
* that need to be taken into account for each of the offsets that
* are used for bailing out of the tail call
*/
pop_bytes = get_pop_bytes(callee_regs_used);
off1 += pop_bytes;
off2 += pop_bytes;
off3 += pop_bytes;
if (stack_depth) {
off1 += 7;
off2 += 7;
off3 += 7;
}
u8 *prog = *pprog, *start = *pprog;
int offset;
/*
* rdi - pointer to ctx
@ -448,8 +441,9 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
EMIT2(0x89, 0xD2); /* mov edx, edx */
EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */
offsetof(struct bpf_array, map.max_entries));
#define OFFSET1 (off1 + RETPOLINE_RCX_BPF_JIT_SIZE) /* Number of bytes to jump */
EMIT2(X86_JBE, OFFSET1); /* jbe out */
offset = ctx->tail_call_indirect_label - (prog + 2 - start);
EMIT2(X86_JBE, offset); /* jbe out */
/*
* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
@ -457,8 +451,9 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
*/
EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */
EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */
#define OFFSET2 (off2 + RETPOLINE_RCX_BPF_JIT_SIZE)
EMIT2(X86_JA, OFFSET2); /* ja out */
offset = ctx->tail_call_indirect_label - (prog + 2 - start);
EMIT2(X86_JA, offset); /* ja out */
EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */
EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */
@ -471,12 +466,11 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
* goto out;
*/
EMIT3(0x48, 0x85, 0xC9); /* test rcx,rcx */
#define OFFSET3 (off3 + RETPOLINE_RCX_BPF_JIT_SIZE)
EMIT2(X86_JE, OFFSET3); /* je out */
*pprog = prog;
pop_callee_regs(pprog, callee_regs_used);
prog = *pprog;
offset = ctx->tail_call_indirect_label - (prog + 2 - start);
EMIT2(X86_JE, offset); /* je out */
pop_callee_regs(&prog, callee_regs_used);
EMIT1(0x58); /* pop rax */
if (stack_depth)
@ -493,41 +487,21 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
* rdi == ctx (1st arg)
* rcx == prog->bpf_func + X86_TAIL_CALL_OFFSET
*/
RETPOLINE_RCX_BPF_JIT();
emit_indirect_jump(&prog, 1 /* rcx */, ip + (prog - start));
/* out: */
ctx->tail_call_indirect_label = prog - start;
*pprog = prog;
}
static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke,
u8 **pprog, int addr, u8 *image,
bool *callee_regs_used, u32 stack_depth)
u8 **pprog, u8 *ip,
bool *callee_regs_used, u32 stack_depth,
struct jit_context *ctx)
{
int tcc_off = -4 - round_up(stack_depth, 8);
u8 *prog = *pprog;
int pop_bytes = 0;
int off1 = 20;
int poke_off;
/* count the additional bytes used for popping callee regs to stack
* that need to be taken into account for jump offset that is used for
* bailing out from of the tail call when limit is reached
*/
pop_bytes = get_pop_bytes(callee_regs_used);
off1 += pop_bytes;
/*
* total bytes for:
* - nop5/ jmpq $off
* - pop callee regs
* - sub rsp, $val if depth > 0
* - pop rax
*/
poke_off = X86_PATCH_SIZE + pop_bytes + 1;
if (stack_depth) {
poke_off += 7;
off1 += 7;
}
u8 *prog = *pprog, *start = *pprog;
int offset;
/*
* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
@ -535,28 +509,30 @@ static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke,
*/
EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */
EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */
EMIT2(X86_JA, off1); /* ja out */
offset = ctx->tail_call_direct_label - (prog + 2 - start);
EMIT2(X86_JA, offset); /* ja out */
EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */
EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */
poke->tailcall_bypass = image + (addr - poke_off - X86_PATCH_SIZE);
poke->tailcall_bypass = ip + (prog - start);
poke->adj_off = X86_TAIL_CALL_OFFSET;
poke->tailcall_target = image + (addr - X86_PATCH_SIZE);
poke->tailcall_target = ip + ctx->tail_call_direct_label - X86_PATCH_SIZE;
poke->bypass_addr = (u8 *)poke->tailcall_target + X86_PATCH_SIZE;
emit_jump(&prog, (u8 *)poke->tailcall_target + X86_PATCH_SIZE,
poke->tailcall_bypass);
*pprog = prog;
pop_callee_regs(pprog, callee_regs_used);
prog = *pprog;
pop_callee_regs(&prog, callee_regs_used);
EMIT1(0x58); /* pop rax */
if (stack_depth)
EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8));
memcpy(prog, x86_nops[5], X86_PATCH_SIZE);
prog += X86_PATCH_SIZE;
/* out: */
ctx->tail_call_direct_label = prog - start;
*pprog = prog;
}
@ -1222,8 +1198,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
/* speculation barrier */
case BPF_ST | BPF_NOSPEC:
if (boot_cpu_has(X86_FEATURE_XMM2))
/* Emit 'lfence' */
EMIT3(0x0F, 0xAE, 0xE8);
EMIT_LFENCE();
break;
/* ST: *(u8*)(dst_reg + off) = imm */
@ -1412,13 +1387,16 @@ st: if (is_imm8(insn->off))
case BPF_JMP | BPF_TAIL_CALL:
if (imm32)
emit_bpf_tail_call_direct(&bpf_prog->aux->poke_tab[imm32 - 1],
&prog, addrs[i], image,
&prog, image + addrs[i - 1],
callee_regs_used,
bpf_prog->aux->stack_depth);
bpf_prog->aux->stack_depth,
ctx);
else
emit_bpf_tail_call_indirect(&prog,
callee_regs_used,
bpf_prog->aux->stack_depth);
bpf_prog->aux->stack_depth,
image + addrs[i - 1],
ctx);
break;
/* cond jump */
@ -2124,24 +2102,6 @@ cleanup:
return ret;
}
static int emit_fallback_jump(u8 **pprog)
{
u8 *prog = *pprog;
int err = 0;
#ifdef CONFIG_RETPOLINE
/* Note that this assumes the the compiler uses external
* thunks for indirect calls. Both clang and GCC use the same
* naming convention for external thunks.
*/
err = emit_jump(&prog, __x86_indirect_thunk_rdx, prog);
#else
EMIT2(0xFF, 0xE2); /* jmp rdx */
#endif
*pprog = prog;
return err;
}
static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
{
u8 *jg_reloc, *prog = *pprog;
@ -2163,9 +2123,7 @@ static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
if (err)
return err;
err = emit_fallback_jump(&prog); /* jmp thunk/indirect */
if (err)
return err;
emit_indirect_jump(&prog, 2 /* rdx */, prog);
*pprog = prog;
return 0;

22
arch/x86/net/bpf_jit_comp32.c
View File

@ -15,6 +15,7 @@
#include <asm/cacheflush.h>
#include <asm/set_memory.h>
#include <asm/nospec-branch.h>
#include <asm/asm-prototypes.h>
#include <linux/bpf.h>
/*
@ -1267,6 +1268,21 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
*pprog = prog;
}
static int emit_jmp_edx(u8 **pprog, u8 *ip)
{
u8 *prog = *pprog;
int cnt = 0;
#ifdef CONFIG_RETPOLINE
EMIT1_off32(0xE9, (u8 *)__x86_indirect_thunk_edx - (ip + 5));
#else
EMIT2(0xFF, 0xE2);
#endif
*pprog = prog;
return cnt;
}
/*
* Generate the following code:
* ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ...
@ -1280,7 +1296,7 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
* goto *(prog->bpf_func + prologue_size);
* out:
*/
static void emit_bpf_tail_call(u8 **pprog)
static void emit_bpf_tail_call(u8 **pprog, u8 *ip)
{
u8 *prog = *pprog;
int cnt = 0;
@ -1362,7 +1378,7 @@ static void emit_bpf_tail_call(u8 **pprog)
* eax == ctx (1st arg)
* edx == prog->bpf_func + prologue_size
*/
RETPOLINE_EDX_BPF_JIT();
cnt += emit_jmp_edx(&prog, ip + cnt);
if (jmp_label1 == -1)
jmp_label1 = cnt;
@ -2122,7 +2138,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
break;
}
case BPF_JMP | BPF_TAIL_CALL:
emit_bpf_tail_call(&prog);
emit_bpf_tail_call(&prog, image + addrs[i - 1]);
break;
/* cond jump */

70
arch/x86/xen/enlighten_pv.c
View File

@ -283,12 +283,12 @@ static void __init xen_init_capabilities(void)
}
}
static void xen_set_debugreg(int reg, unsigned long val)
static noinstr void xen_set_debugreg(int reg, unsigned long val)
{
HYPERVISOR_set_debugreg(reg, val);
}
static unsigned long xen_get_debugreg(int reg)
static noinstr unsigned long xen_get_debugreg(int reg)
{
return HYPERVISOR_get_debugreg(reg);
}
@ -1025,52 +1025,54 @@ static const struct pv_info xen_info __initconst = {
.name = "Xen",
};
static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.cpuid = xen_cpuid,
static const typeof(pv_ops) xen_cpu_ops __initconst = {
.cpu = {
.cpuid = xen_cpuid,
.set_debugreg = xen_set_debugreg,
.get_debugreg = xen_get_debugreg,
.set_debugreg = xen_set_debugreg,
.get_debugreg = xen_get_debugreg,
.read_cr0 = xen_read_cr0,
.write_cr0 = xen_write_cr0,
.read_cr0 = xen_read_cr0,
.write_cr0 = xen_write_cr0,
.write_cr4 = xen_write_cr4,
.write_cr4 = xen_write_cr4,
.wbinvd = native_wbinvd,
.wbinvd = native_wbinvd,
.read_msr = xen_read_msr,
.write_msr = xen_write_msr,
.read_msr = xen_read_msr,
.write_msr = xen_write_msr,
.read_msr_safe = xen_read_msr_safe,
.write_msr_safe = xen_write_msr_safe,
.read_msr_safe = xen_read_msr_safe,
.write_msr_safe = xen_write_msr_safe,
.read_pmc = xen_read_pmc,
.read_pmc = xen_read_pmc,
.load_tr_desc = paravirt_nop,
.set_ldt = xen_set_ldt,
.load_gdt = xen_load_gdt,
.load_idt = xen_load_idt,
.load_tls = xen_load_tls,
.load_gs_index = xen_load_gs_index,
.load_tr_desc = paravirt_nop,
.set_ldt = xen_set_ldt,
.load_gdt = xen_load_gdt,
.load_idt = xen_load_idt,
.load_tls = xen_load_tls,
.load_gs_index = xen_load_gs_index,
.alloc_ldt = xen_alloc_ldt,
.free_ldt = xen_free_ldt,
.alloc_ldt = xen_alloc_ldt,
.free_ldt = xen_free_ldt,
.store_tr = xen_store_tr,
.store_tr = xen_store_tr,
.write_ldt_entry = xen_write_ldt_entry,
.write_gdt_entry = xen_write_gdt_entry,
.write_idt_entry = xen_write_idt_entry,
.load_sp0 = xen_load_sp0,
.write_ldt_entry = xen_write_ldt_entry,
.write_gdt_entry = xen_write_gdt_entry,
.write_idt_entry = xen_write_idt_entry,
.load_sp0 = xen_load_sp0,
#ifdef CONFIG_X86_IOPL_IOPERM
.invalidate_io_bitmap = xen_invalidate_io_bitmap,
.update_io_bitmap = xen_update_io_bitmap,
.invalidate_io_bitmap = xen_invalidate_io_bitmap,
.update_io_bitmap = xen_update_io_bitmap,
#endif
.io_delay = xen_io_delay,
.io_delay = xen_io_delay,
.start_context_switch = paravirt_start_context_switch,
.end_context_switch = xen_end_context_switch,
.start_context_switch = paravirt_start_context_switch,
.end_context_switch = xen_end_context_switch,
},
};
static void xen_restart(char *msg)
@ -1211,7 +1213,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
/* Install Xen paravirt ops */
pv_info = xen_info;
pv_ops.cpu = xen_cpu_ops;
pv_ops.cpu = xen_cpu_ops.cpu;
paravirt_iret = xen_iret;
xen_init_irq_ops();

31
arch/x86/xen/irq.c
View File

@ -19,12 +19,12 @@
* callback mask. We do this in a very simple manner, by making a call
* down into Xen. The pending flag will be checked by Xen on return.
*/
void xen_force_evtchn_callback(void)
noinstr void xen_force_evtchn_callback(void)
{
(void)HYPERVISOR_xen_version(0, NULL);
}
asmlinkage __visible unsigned long xen_save_fl(void)
asmlinkage __visible noinstr unsigned long xen_save_fl(void)
{
struct vcpu_info *vcpu;
unsigned long flags;
@ -40,9 +40,9 @@ asmlinkage __visible unsigned long xen_save_fl(void)
*/
return (-flags) & X86_EFLAGS_IF;
}
PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl);
__PV_CALLEE_SAVE_REGS_THUNK(xen_save_fl, ".noinstr.text");
asmlinkage __visible void xen_irq_disable(void)
asmlinkage __visible noinstr void xen_irq_disable(void)
{
/* There's a one instruction preempt window here. We need to
make sure we're don't switch CPUs between getting the vcpu
@ -51,9 +51,9 @@ asmlinkage __visible void xen_irq_disable(void)
this_cpu_read(xen_vcpu)->evtchn_upcall_mask = 1;
preempt_enable_no_resched();
}
PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable);
__PV_CALLEE_SAVE_REGS_THUNK(xen_irq_disable, ".noinstr.text");
asmlinkage __visible void xen_irq_enable(void)
asmlinkage __visible noinstr void xen_irq_enable(void)
{
struct vcpu_info *vcpu;
@ -76,7 +76,7 @@ asmlinkage __visible void xen_irq_enable(void)
preempt_enable();
}
PV_CALLEE_SAVE_REGS_THUNK(xen_irq_enable);
__PV_CALLEE_SAVE_REGS_THUNK(xen_irq_enable, ".noinstr.text");
static void xen_safe_halt(void)
{
@ -94,17 +94,20 @@ static void xen_halt(void)
xen_safe_halt();
}
static const struct pv_irq_ops xen_irq_ops __initconst = {
.save_fl = PV_CALLEE_SAVE(xen_save_fl),
.irq_disable = PV_CALLEE_SAVE(xen_irq_disable),
.irq_enable = PV_CALLEE_SAVE(xen_irq_enable),
static const typeof(pv_ops) xen_irq_ops __initconst = {
.irq = {
.safe_halt = xen_safe_halt,
.halt = xen_halt,
.save_fl = PV_CALLEE_SAVE(xen_save_fl),
.irq_disable = PV_CALLEE_SAVE(xen_irq_disable),
.irq_enable = PV_CALLEE_SAVE(xen_irq_enable),
.safe_halt = xen_safe_halt,
.halt = xen_halt,
},
};
void __init xen_init_irq_ops(void)
{
pv_ops.irq = xen_irq_ops;
pv_ops.irq = xen_irq_ops.irq;
x86_init.irqs.intr_init = xen_init_IRQ;
}

93
arch/x86/xen/mmu_pv.c
View File

@ -1204,7 +1204,8 @@ static void __init xen_pagetable_init(void)
xen_remap_memory();
xen_setup_mfn_list_list();
}
static void xen_write_cr2(unsigned long cr2)
static noinstr void xen_write_cr2(unsigned long cr2)
{
this_cpu_read(xen_vcpu)->arch.cr2 = cr2;
}
@ -2078,67 +2079,69 @@ static void xen_leave_lazy_mmu(void)
preempt_enable();
}
static const struct pv_mmu_ops xen_mmu_ops __initconst = {
.read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2),
.write_cr2 = xen_write_cr2,
static const typeof(pv_ops) xen_mmu_ops __initconst = {
.mmu = {
.read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2),
.write_cr2 = xen_write_cr2,
.read_cr3 = xen_read_cr3,
.write_cr3 = xen_write_cr3_init,
.read_cr3 = xen_read_cr3,
.write_cr3 = xen_write_cr3_init,
.flush_tlb_user = xen_flush_tlb,
.flush_tlb_kernel = xen_flush_tlb,
.flush_tlb_one_user = xen_flush_tlb_one_user,
.flush_tlb_multi = xen_flush_tlb_multi,
.tlb_remove_table = tlb_remove_table,
.flush_tlb_user = xen_flush_tlb,
.flush_tlb_kernel = xen_flush_tlb,
.flush_tlb_one_user = xen_flush_tlb_one_user,
.flush_tlb_multi = xen_flush_tlb_multi,
.tlb_remove_table = tlb_remove_table,
.pgd_alloc = xen_pgd_alloc,
.pgd_free = xen_pgd_free,
.pgd_alloc = xen_pgd_alloc,
.pgd_free = xen_pgd_free,
.alloc_pte = xen_alloc_pte_init,
.release_pte = xen_release_pte_init,
.alloc_pmd = xen_alloc_pmd_init,
.release_pmd = xen_release_pmd_init,
.alloc_pte = xen_alloc_pte_init,
.release_pte = xen_release_pte_init,
.alloc_pmd = xen_alloc_pmd_init,
.release_pmd = xen_release_pmd_init,
.set_pte = xen_set_pte_init,
.set_pmd = xen_set_pmd_hyper,
.set_pte = xen_set_pte_init,
.set_pmd = xen_set_pmd_hyper,
.ptep_modify_prot_start = xen_ptep_modify_prot_start,
.ptep_modify_prot_commit = xen_ptep_modify_prot_commit,
.ptep_modify_prot_start = xen_ptep_modify_prot_start,
.ptep_modify_prot_commit = xen_ptep_modify_prot_commit,
.pte_val = PV_CALLEE_SAVE(xen_pte_val),
.pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
.pte_val = PV_CALLEE_SAVE(xen_pte_val),
.pgd_val = PV_CALLEE_SAVE(xen_pgd_val),
.make_pte = PV_CALLEE_SAVE(xen_make_pte_init),
.make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
.make_pte = PV_CALLEE_SAVE(xen_make_pte_init),
.make_pgd = PV_CALLEE_SAVE(xen_make_pgd),
.set_pud = xen_set_pud_hyper,
.set_pud = xen_set_pud_hyper,
.make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
.pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
.make_pmd = PV_CALLEE_SAVE(xen_make_pmd),
.pmd_val = PV_CALLEE_SAVE(xen_pmd_val),
.pud_val = PV_CALLEE_SAVE(xen_pud_val),
.make_pud = PV_CALLEE_SAVE(xen_make_pud),
.set_p4d = xen_set_p4d_hyper,
.pud_val = PV_CALLEE_SAVE(xen_pud_val),
.make_pud = PV_CALLEE_SAVE(xen_make_pud),
.set_p4d = xen_set_p4d_hyper,
.alloc_pud = xen_alloc_pmd_init,
.release_pud = xen_release_pmd_init,
.alloc_pud = xen_alloc_pmd_init,
.release_pud = xen_release_pmd_init,
#if CONFIG_PGTABLE_LEVELS >= 5
.p4d_val = PV_CALLEE_SAVE(xen_p4d_val),
.make_p4d = PV_CALLEE_SAVE(xen_make_p4d),
.p4d_val = PV_CALLEE_SAVE(xen_p4d_val),
.make_p4d = PV_CALLEE_SAVE(xen_make_p4d),
#endif
.activate_mm = xen_activate_mm,
.dup_mmap = xen_dup_mmap,
.exit_mmap = xen_exit_mmap,
.activate_mm = xen_activate_mm,
.dup_mmap = xen_dup_mmap,
.exit_mmap = xen_exit_mmap,
.lazy_mode = {
.enter = paravirt_enter_lazy_mmu,
.leave = xen_leave_lazy_mmu,
.flush = paravirt_flush_lazy_mmu,
.lazy_mode = {
.enter = paravirt_enter_lazy_mmu,
.leave = xen_leave_lazy_mmu,
.flush = paravirt_flush_lazy_mmu,
},
.set_fixmap = xen_set_fixmap,
},
.set_fixmap = xen_set_fixmap,
};
void __init xen_init_mmu_ops(void)
@ -2146,7 +2149,7 @@ void __init xen_init_mmu_ops(void)
x86_init.paging.pagetable_init = xen_pagetable_init;
x86_init.hyper.init_after_bootmem = xen_after_bootmem;
pv_ops.mmu = xen_mmu_ops;
pv_ops.mmu = xen_mmu_ops.mmu;
memset(dummy_mapping, 0xff, PAGE_SIZE);
}

87
arch/x86/xen/xen-asm.S
View File

@ -21,33 +21,7 @@
#include <linux/init.h>
#include <linux/linkage.h>
/*
* Enable events. This clears the event mask and tests the pending
* event status with one and operation. If there are pending events,
* then enter the hypervisor to get them handled.
*/
SYM_FUNC_START(xen_irq_enable_direct)
FRAME_BEGIN
/* Unmask events */
movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
/*
* Preempt here doesn't matter because that will deal with any
* pending interrupts. The pending check may end up being run
* on the wrong CPU, but that doesn't hurt.
*/
/* Test for pending */
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
jz 1f
call check_events
1:
FRAME_END
ret
SYM_FUNC_END(xen_irq_enable_direct)
.pushsection .noinstr.text, "ax"
/*
* Disabling events is simply a matter of making the event mask
* non-zero.
@ -57,22 +31,6 @@ SYM_FUNC_START(xen_irq_disable_direct)
ret
SYM_FUNC_END(xen_irq_disable_direct)
/*
* (xen_)save_fl is used to get the current interrupt enable status.
* Callers expect the status to be in X86_EFLAGS_IF, and other bits
* may be set in the return value. We take advantage of this by
* making sure that X86_EFLAGS_IF has the right value (and other bits
* in that byte are 0), but other bits in the return value are
* undefined. We need to toggle the state of the bit, because Xen and
* x86 use opposite senses (mask vs enable).
*/
SYM_FUNC_START(xen_save_fl_direct)
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
setz %ah
addb %ah, %ah
ret
SYM_FUNC_END(xen_save_fl_direct)
/*
* Force an event check by making a hypercall, but preserve regs
* before making the call.
@ -102,6 +60,48 @@ SYM_FUNC_START(check_events)
ret
SYM_FUNC_END(check_events)
/*
* Enable events. This clears the event mask and tests the pending
* event status with one and operation. If there are pending events,
* then enter the hypervisor to get them handled.
*/
SYM_FUNC_START(xen_irq_enable_direct)
FRAME_BEGIN
/* Unmask events */
movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
/*
* Preempt here doesn't matter because that will deal with any
* pending interrupts. The pending check may end up being run
* on the wrong CPU, but that doesn't hurt.
*/
/* Test for pending */
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_pending
jz 1f
call check_events
1:
FRAME_END
ret
SYM_FUNC_END(xen_irq_enable_direct)
/*
* (xen_)save_fl is used to get the current interrupt enable status.
* Callers expect the status to be in X86_EFLAGS_IF, and other bits
* may be set in the return value. We take advantage of this by
* making sure that X86_EFLAGS_IF has the right value (and other bits
* in that byte are 0), but other bits in the return value are
* undefined. We need to toggle the state of the bit, because Xen and
* x86 use opposite senses (mask vs enable).
*/
SYM_FUNC_START(xen_save_fl_direct)
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
setz %ah
addb %ah, %ah
ret
SYM_FUNC_END(xen_save_fl_direct)
SYM_FUNC_START(xen_read_cr2)
FRAME_BEGIN
_ASM_MOV PER_CPU_VAR(xen_vcpu), %_ASM_AX
@ -116,6 +116,7 @@ SYM_FUNC_START(xen_read_cr2_direct)
FRAME_END
ret
SYM_FUNC_END(xen_read_cr2_direct);
.popsection
.macro xen_pv_trap name
SYM_CODE_START(xen_\name)

34
arch/x86/xen/xen-head.S
View File

@ -20,6 +20,23 @@
#include <xen/interface/xen-mca.h>
#include <asm/xen/interface.h>
.pushsection .noinstr.text, "ax"
.balign PAGE_SIZE
SYM_CODE_START(hypercall_page)
.rept (PAGE_SIZE / 32)
UNWIND_HINT_FUNC
.skip 31, 0x90
ret
.endr
#define HYPERCALL(n) \
.equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
.type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
#include <asm/xen-hypercalls.h>
#undef HYPERCALL
SYM_CODE_END(hypercall_page)
.popsection
#ifdef CONFIG_XEN_PV
__INIT
SYM_CODE_START(startup_xen)
@ -64,23 +81,6 @@ SYM_CODE_END(asm_cpu_bringup_and_idle)
#endif
#endif
.pushsection .text
.balign PAGE_SIZE
SYM_CODE_START(hypercall_page)
.rept (PAGE_SIZE / 32)
UNWIND_HINT_FUNC
.skip 31, 0x90
ret
.endr
#define HYPERCALL(n) \
.equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
.type xen_hypercall_##n, @function; .size xen_hypercall_##n, 32
#include <asm/xen-hypercalls.h>
#undef HYPERCALL
SYM_CODE_END(hypercall_page)
.popsection
ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS, .asciz "linux")
ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION, .asciz "2.6")
ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION, .asciz "xen-3.0")

2
include/linux/context_tracking.h
View File

@ -105,7 +105,7 @@ static inline void user_exit_irqoff(void) { }
static inline enum ctx_state exception_enter(void) { return 0; }
static inline void exception_exit(enum ctx_state prev_ctx) { }
static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
static inline bool context_tracking_guest_enter(void) { return false; }
static __always_inline bool context_tracking_guest_enter(void) { return false; }
static inline void context_tracking_guest_exit(void) { }
#endif /* !CONFIG_CONTEXT_TRACKING */

2
kernel/locking/lockdep.c
View File

@ -888,7 +888,7 @@ look_up_lock_class(const struct lockdep_map *lock, unsigned int subclass)
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return NULL;
hlist_for_each_entry_rcu(class, hash_head, hash_entry) {
hlist_for_each_entry_rcu_notrace(class, hash_head, hash_entry) {
if (class->key == key) {
/*
* Huh! same key, different name? Did someone trample

2
lib/Kconfig.debug
View File

@ -458,7 +458,7 @@ config STACK_VALIDATION
config VMLINUX_VALIDATION
bool
depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
depends on STACK_VALIDATION && DEBUG_ENTRY
default y
config VMLINUX_MAP

180
tools/objtool/arch/x86/decode.c
View File

@ -20,6 +20,7 @@
#include <objtool/arch.h>
#include <objtool/warn.h>
#include <objtool/endianness.h>
#include <objtool/builtin.h>
#include <arch/elf.h>
static int is_x86_64(const struct elf *elf)
@ -102,12 +103,13 @@ unsigned long arch_jump_destination(struct instruction *insn)
#define rm_is_mem(reg) (mod_is_mem() && !is_RIP() && rm_is(reg))
#define rm_is_reg(reg) (mod_is_reg() && modrm_rm == (reg))
int arch_decode_instruction(const struct elf *elf, const struct section *sec,
int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
unsigned long *immediate,
struct list_head *ops_list)
{
const struct elf *elf = file->elf;
struct insn insn;
int x86_64, ret;
unsigned char op1, op2,
@ -544,6 +546,36 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,
*type = INSN_RETURN;
break;
case 0xc7: /* mov imm, r/m */
if (!noinstr)
break;
if (insn.length == 3+4+4 && !strncmp(sec->name, ".init.text", 10)) {
struct reloc *immr, *disp;
struct symbol *func;
int idx;
immr = find_reloc_by_dest(elf, (void *)sec, offset+3);
disp = find_reloc_by_dest(elf, (void *)sec, offset+7);
if (!immr || strcmp(immr->sym->name, "pv_ops"))
break;
idx = (immr->addend + 8) / sizeof(void *);
func = disp->sym;
if (disp->sym->type == STT_SECTION)
func = find_symbol_by_offset(disp->sym->sec, disp->addend);
if (!func) {
WARN("no func for pv_ops[]");
return -1;
}
objtool_pv_add(file, idx, func);
}
break;
case 0xcf: /* iret */
/*
* Handle sync_core(), which has an IRET to self.
@ -659,154 +691,52 @@ const char *arch_nop_insn(int len)
return nops[len-1];
}
/* asm/alternative.h ? */
#define BYTE_RET 0xC3
#define ALTINSTR_FLAG_INV (1 << 15)
#define ALT_NOT(feat) ((feat) | ALTINSTR_FLAG_INV)
struct alt_instr {
s32 instr_offset; /* original instruction */
s32 repl_offset; /* offset to replacement instruction */
u16 cpuid; /* cpuid bit set for replacement */
u8 instrlen; /* length of original instruction */
u8 replacementlen; /* length of new instruction */
} __packed;
static int elf_add_alternative(struct elf *elf,
struct instruction *orig, struct symbol *sym,
int cpuid, u8 orig_len, u8 repl_len)
const char *arch_ret_insn(int len)
{
const int size = sizeof(struct alt_instr);
struct alt_instr *alt;
struct section *sec;
Elf_Scn *s;
static const char ret[5][5] = {
{ BYTE_RET },
{ BYTE_RET, BYTES_NOP1 },
{ BYTE_RET, BYTES_NOP2 },
{ BYTE_RET, BYTES_NOP3 },
{ BYTE_RET, BYTES_NOP4 },
};
sec = find_section_by_name(elf, ".altinstructions");
if (!sec) {
sec = elf_create_section(elf, ".altinstructions",
SHF_ALLOC, 0, 0);
if (!sec) {
WARN_ELF("elf_create_section");
return -1;
}
if (len < 1 || len > 5) {
WARN("invalid RET size: %d\n", len);
return NULL;
}
s = elf_getscn(elf->elf, sec->idx);
if (!s) {
WARN_ELF("elf_getscn");
return -1;
}
sec->data = elf_newdata(s);
if (!sec->data) {
WARN_ELF("elf_newdata");
return -1;
}
sec->data->d_size = size;
sec->data->d_align = 1;
alt = sec->data->d_buf = malloc(size);
if (!sec->data->d_buf) {
perror("malloc");
return -1;
}
memset(sec->data->d_buf, 0, size);
if (elf_add_reloc_to_insn(elf, sec, sec->sh.sh_size,
R_X86_64_PC32, orig->sec, orig->offset)) {
WARN("elf_create_reloc: alt_instr::instr_offset");
return -1;
}
if (elf_add_reloc(elf, sec, sec->sh.sh_size + 4,
R_X86_64_PC32, sym, 0)) {
WARN("elf_create_reloc: alt_instr::repl_offset");
return -1;
}
alt->cpuid = bswap_if_needed(cpuid);
alt->instrlen = orig_len;
alt->replacementlen = repl_len;
sec->sh.sh_size += size;
sec->changed = true;
return 0;
return ret[len-1];
}
#define X86_FEATURE_RETPOLINE ( 7*32+12)
int arch_rewrite_retpolines(struct objtool_file *file)
int arch_decode_hint_reg(u8 sp_reg, int *base)
{
struct instruction *insn;
struct reloc *reloc;
struct symbol *sym;
char name[32] = "";
list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
if (insn->type != INSN_JUMP_DYNAMIC &&
insn->type != INSN_CALL_DYNAMIC)
continue;
if (!strcmp(insn->sec->name, ".text.__x86.indirect_thunk"))
continue;
reloc = insn->reloc;
sprintf(name, "__x86_indirect_alt_%s_%s",
insn->type == INSN_JUMP_DYNAMIC ? "jmp" : "call",
reloc->sym->name + 21);
sym = find_symbol_by_name(file->elf, name);
if (!sym) {
sym = elf_create_undef_symbol(file->elf, name);
if (!sym) {
WARN("elf_create_undef_symbol");
return -1;
}
}
if (elf_add_alternative(file->elf, insn, sym,
ALT_NOT(X86_FEATURE_RETPOLINE), 5, 5)) {
WARN("elf_add_alternative");
return -1;
}
}
return 0;
}
int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg)
{
struct cfi_reg *cfa = &insn->cfi.cfa;
switch (sp_reg) {
case ORC_REG_UNDEFINED:
cfa->base = CFI_UNDEFINED;
*base = CFI_UNDEFINED;
break;
case ORC_REG_SP:
cfa->base = CFI_SP;
*base = CFI_SP;
break;
case ORC_REG_BP:
cfa->base = CFI_BP;
*base = CFI_BP;
break;
case ORC_REG_SP_INDIRECT:
cfa->base = CFI_SP_INDIRECT;
*base = CFI_SP_INDIRECT;
break;
case ORC_REG_R10:
cfa->base = CFI_R10;
*base = CFI_R10;
break;
case ORC_REG_R13:
cfa->base = CFI_R13;
*base = CFI_R13;
break;
case ORC_REG_DI:
cfa->base = CFI_DI;
*base = CFI_DI;
break;
case ORC_REG_DX:
cfa->base = CFI_DX;
*base = CFI_DX;
break;
default:
return -1;

646
tools/objtool/check.c
View File

@ -5,6 +5,7 @@
#include <string.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <arch/elf.h>
#include <objtool/builtin.h>
@ -26,7 +27,11 @@ struct alternative {
bool skip_orig;
};
struct cfi_init_state initial_func_cfi;
static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache;
static struct cfi_init_state initial_func_cfi;
static struct cfi_state init_cfi;
static struct cfi_state func_cfi;
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset)
@ -173,6 +178,7 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
"rewind_stack_do_exit",
"kunit_try_catch_throw",
"xen_start_kernel",
"cpu_bringup_and_idle",
};
if (!func)
@ -265,6 +271,78 @@ static void init_insn_state(struct insn_state *state, struct section *sec)
state->noinstr = sec->noinstr;
}
static struct cfi_state *cfi_alloc(void)
{
struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
if (!cfi) {
WARN("calloc failed");
exit(1);
}
nr_cfi++;
return cfi;
}
static int cfi_bits;
static struct hlist_head *cfi_hash;
static inline bool cficmp(struct cfi_state *cfi1, struct cfi_state *cfi2)
{
return memcmp((void *)cfi1 + sizeof(cfi1->hash),
(void *)cfi2 + sizeof(cfi2->hash),
sizeof(struct cfi_state) - sizeof(struct hlist_node));
}
static inline u32 cfi_key(struct cfi_state *cfi)
{
return jhash((void *)cfi + sizeof(cfi->hash),
sizeof(*cfi) - sizeof(cfi->hash), 0);
}
static struct cfi_state *cfi_hash_find_or_add(struct cfi_state *cfi)
{
struct hlist_head *head = &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)];
struct cfi_state *obj;
hlist_for_each_entry(obj, head, hash) {
if (!cficmp(cfi, obj)) {
nr_cfi_cache++;
return obj;
}
}
obj = cfi_alloc();
*obj = *cfi;
hlist_add_head(&obj->hash, head);
return obj;
}
static void cfi_hash_add(struct cfi_state *cfi)
{
struct hlist_head *head = &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)];
hlist_add_head(&cfi->hash, head);
}
static void *cfi_hash_alloc(unsigned long size)
{
cfi_bits = max(10, ilog2(size));
cfi_hash = mmap(NULL, sizeof(struct hlist_head) << cfi_bits,
PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANON, -1, 0);
if (cfi_hash == (void *)-1L) {
WARN("mmap fail cfi_hash");
cfi_hash = NULL;
} else if (stats) {
printf("cfi_bits: %d\n", cfi_bits);
}
return cfi_hash;
}
static unsigned long nr_insns;
static unsigned long nr_insns_visited;
/*
* Call the arch-specific instruction decoder for all the instructions and add
* them to the global instruction list.
@ -275,7 +353,6 @@ static int decode_instructions(struct objtool_file *file)
struct symbol *func;
unsigned long offset;
struct instruction *insn;
unsigned long nr_insns = 0;
int ret;
for_each_sec(file, sec) {
@ -301,12 +378,11 @@ static int decode_instructions(struct objtool_file *file)
memset(insn, 0, sizeof(*insn));
INIT_LIST_HEAD(&insn->alts);
INIT_LIST_HEAD(&insn->stack_ops);
init_cfi_state(&insn->cfi);
insn->sec = sec;
insn->offset = offset;
ret = arch_decode_instruction(file->elf, sec, offset,
ret = arch_decode_instruction(file, sec, offset,
sec->sh.sh_size - offset,
&insn->len, &insn->type,
&insn->immediate,
@ -344,6 +420,82 @@ err:
return ret;
}
/*
* Read the pv_ops[] .data table to find the static initialized values.
*/
static int add_pv_ops(struct objtool_file *file, const char *symname)
{
struct symbol *sym, *func;
unsigned long off, end;
struct reloc *rel;
int idx;
sym = find_symbol_by_name(file->elf, symname);
if (!sym)
return 0;
off = sym->offset;
end = off + sym->len;
for (;;) {
rel = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off);
if (!rel)
break;
func = rel->sym;
if (func->type == STT_SECTION)
func = find_symbol_by_offset(rel->sym->sec, rel->addend);
idx = (rel->offset - sym->offset) / sizeof(unsigned long);
objtool_pv_add(file, idx, func);
off = rel->offset + 1;
if (off > end)
break;
}
return 0;
}
/*
* Allocate and initialize file->pv_ops[].
*/
static int init_pv_ops(struct objtool_file *file)
{
static const char *pv_ops_tables[] = {
"pv_ops",
"xen_cpu_ops",
"xen_irq_ops",
"xen_mmu_ops",
NULL,
};
const char *pv_ops;
struct symbol *sym;
int idx, nr;
if (!noinstr)
return 0;
file->pv_ops = NULL;
sym = find_symbol_by_name(file->elf, "pv_ops");
if (!sym)
return 0;
nr = sym->len / sizeof(unsigned long);
file->pv_ops = calloc(sizeof(struct pv_state), nr);
if (!file->pv_ops)
return -1;
for (idx = 0; idx < nr; idx++)
INIT_LIST_HEAD(&file->pv_ops[idx].targets);
for (idx = 0; (pv_ops = pv_ops_tables[idx]); idx++)
add_pv_ops(file, pv_ops);
return 0;
}
static struct instruction *find_last_insn(struct objtool_file *file,
struct section *sec)
{
@ -531,6 +683,52 @@ static int create_static_call_sections(struct objtool_file *file)
return 0;
}
static int create_retpoline_sites_sections(struct objtool_file *file)
{
struct instruction *insn;
struct section *sec;
int idx;
sec = find_section_by_name(file->elf, ".retpoline_sites");
if (sec) {
WARN("file already has .retpoline_sites, skipping");
return 0;
}
idx = 0;
list_for_each_entry(insn, &file->retpoline_call_list, call_node)
idx++;
if (!idx)
return 0;
sec = elf_create_section(file->elf, ".retpoline_sites", 0,
sizeof(int), idx);
if (!sec) {
WARN("elf_create_section: .retpoline_sites");
return -1;
}
idx = 0;
list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
int *site = (int *)sec->data->d_buf + idx;
*site = 0;
if (elf_add_reloc_to_insn(file->elf, sec,
idx * sizeof(int),
R_X86_64_PC32,
insn->sec, insn->offset)) {
WARN("elf_add_reloc_to_insn: .retpoline_sites");
return -1;
}
idx++;
}
return 0;
}
static int create_mcount_loc_sections(struct objtool_file *file)
{
struct section *sec;
@ -549,7 +747,7 @@ static int create_mcount_loc_sections(struct objtool_file *file)
return 0;
idx = 0;
list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node)
list_for_each_entry(insn, &file->mcount_loc_list, call_node)
idx++;
sec = elf_create_section(file->elf, "__mcount_loc", 0, sizeof(unsigned long), idx);
@ -557,7 +755,7 @@ static int create_mcount_loc_sections(struct objtool_file *file)
return -1;
idx = 0;
list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) {
list_for_each_entry(insn, &file->mcount_loc_list, call_node) {
loc = (unsigned long *)sec->data->d_buf + idx;
memset(loc, 0, sizeof(unsigned long));
@ -817,6 +1015,9 @@ static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *i
return NULL;
if (!insn->reloc) {
if (!file)
return NULL;
insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec,
insn->offset, insn->len);
if (!insn->reloc) {
@ -828,6 +1029,136 @@ static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *i
return insn->reloc;
}
static void remove_insn_ops(struct instruction *insn)
{
struct stack_op *op, *tmp;
list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
list_del(&op->list);
free(op);
}
}
static void annotate_call_site(struct objtool_file *file,
struct instruction *insn, bool sibling)
{
struct reloc *reloc = insn_reloc(file, insn);
struct symbol *sym = insn->call_dest;
if (!sym)
sym = reloc->sym;
/*
* Alternative replacement code is just template code which is
* sometimes copied to the original instruction. For now, don't
* annotate it. (In the future we might consider annotating the
* original instruction if/when it ever makes sense to do so.)
*/
if (!strcmp(insn->sec->name, ".altinstr_replacement"))
return;
if (sym->static_call_tramp) {
list_add_tail(&insn->call_node, &file->static_call_list);
return;
}
if (sym->retpoline_thunk) {
list_add_tail(&insn->call_node, &file->retpoline_call_list);
return;
}
/*
* Many compilers cannot disable KCOV with a function attribute
* so they need a little help, NOP out any KCOV calls from noinstr
* text.
*/
if (insn->sec->noinstr && sym->kcov) {
if (reloc) {
reloc->type = R_NONE;
elf_write_reloc(file->elf, reloc);
}
elf_write_insn(file->elf, insn->sec,
insn->offset, insn->len,
sibling ? arch_ret_insn(insn->len)
: arch_nop_insn(insn->len));
insn->type = sibling ? INSN_RETURN : INSN_NOP;
return;
}
if (mcount && sym->fentry) {
if (sibling)
WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset);
if (reloc) {
reloc->type = R_NONE;
elf_write_reloc(file->elf, reloc);
}
elf_write_insn(file->elf, insn->sec,
insn->offset, insn->len,
arch_nop_insn(insn->len));
insn->type = INSN_NOP;
list_add_tail(&insn->call_node, &file->mcount_loc_list);
return;
}
}
static void add_call_dest(struct objtool_file *file, struct instruction *insn,
struct symbol *dest, bool sibling)
{
insn->call_dest = dest;
if (!dest)
return;
/*
* Whatever stack impact regular CALLs have, should be undone
* by the RETURN of the called function.
*
* Annotated intra-function calls retain the stack_ops but
* are converted to JUMP, see read_intra_function_calls().
*/
remove_insn_ops(insn);
annotate_call_site(file, insn, sibling);
}
static void add_retpoline_call(struct objtool_file *file, struct instruction *insn)
{
/*
* Retpoline calls/jumps are really dynamic calls/jumps in disguise,
* so convert them accordingly.
*/
switch (insn->type) {
case INSN_CALL:
insn->type = INSN_CALL_DYNAMIC;
break;
case INSN_JUMP_UNCONDITIONAL:
insn->type = INSN_JUMP_DYNAMIC;
break;
case INSN_JUMP_CONDITIONAL:
insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
break;
default:
return;
}
insn->retpoline_safe = true;
/*
* Whatever stack impact regular CALLs have, should be undone
* by the RETURN of the called function.
*
* Annotated intra-function calls retain the stack_ops but
* are converted to JUMP, see read_intra_function_calls().
*/
remove_insn_ops(insn);
annotate_call_site(file, insn, false);
}
/*
* Find the destination instructions for all jumps.
*/
@ -849,28 +1180,12 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
} else if (arch_is_retpoline(reloc->sym)) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
*/
if (insn->type == INSN_JUMP_UNCONDITIONAL)
insn->type = INSN_JUMP_DYNAMIC;
else
insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
list_add_tail(&insn->call_node,
&file->retpoline_call_list);
insn->retpoline_safe = true;
} else if (reloc->sym->retpoline_thunk) {
add_retpoline_call(file, insn);
continue;
} else if (insn->func) {
/* internal or external sibling call (with reloc) */
insn->call_dest = reloc->sym;
if (insn->call_dest->static_call_tramp) {
list_add_tail(&insn->call_node,
&file->static_call_list);
}
add_call_dest(file, insn, reloc->sym, true);
continue;
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
@ -926,13 +1241,8 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
insn->jump_dest->offset == insn->jump_dest->func->offset) {
/* internal sibling call (without reloc) */
insn->call_dest = insn->jump_dest->func;
if (insn->call_dest->static_call_tramp) {
list_add_tail(&insn->call_node,
&file->static_call_list);
}
add_call_dest(file, insn, insn->jump_dest->func, true);
}
}
}
@ -940,16 +1250,6 @@ static int add_jump_destinations(struct objtool_file *file)
return 0;
}
static void remove_insn_ops(struct instruction *insn)
{
struct stack_op *op, *tmp;
list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
list_del(&op->list);
free(op);
}
}
static struct symbol *find_call_destination(struct section *sec, unsigned long offset)
{
struct symbol *call_dest;
@ -968,6 +1268,7 @@ static int add_call_destinations(struct objtool_file *file)
{
struct instruction *insn;
unsigned long dest_off;
struct symbol *dest;
struct reloc *reloc;
for_each_insn(file, insn) {
@ -977,7 +1278,9 @@ static int add_call_destinations(struct objtool_file *file)
reloc = insn_reloc(file, insn);
if (!reloc) {
dest_off = arch_jump_destination(insn);
insn->call_dest = find_call_destination(insn->sec, dest_off);
dest = find_call_destination(insn->sec, dest_off);
add_call_dest(file, insn, dest, false);
if (insn->ignore)
continue;
@ -995,9 +1298,8 @@ static int add_call_destinations(struct objtool_file *file)
} else if (reloc->sym->type == STT_SECTION) {
dest_off = arch_dest_reloc_offset(reloc->addend);
insn->call_dest = find_call_destination(reloc->sym->sec,
dest_off);
if (!insn->call_dest) {
dest = find_call_destination(reloc->sym->sec, dest_off);
if (!dest) {
WARN_FUNC("can't find call dest symbol at %s+0x%lx",
insn->sec, insn->offset,
reloc->sym->sec->name,
@ -1005,70 +1307,13 @@ static int add_call_destinations(struct objtool_file *file)
return -1;
}
} else if (arch_is_retpoline(reloc->sym)) {
/*
* Retpoline calls are really dynamic calls in
* disguise, so convert them accordingly.
*/
insn->type = INSN_CALL_DYNAMIC;
insn->retpoline_safe = true;
add_call_dest(file, insn, dest, false);
list_add_tail(&insn->call_node,
&file->retpoline_call_list);
remove_insn_ops(insn);
continue;
} else if (reloc->sym->retpoline_thunk) {
add_retpoline_call(file, insn);
} else
insn->call_dest = reloc->sym;
if (insn->call_dest && insn->call_dest->static_call_tramp) {
list_add_tail(&insn->call_node,
&file->static_call_list);
}
/*
* Many compilers cannot disable KCOV with a function attribute
* so they need a little help, NOP out any KCOV calls from noinstr
* text.
*/
if (insn->sec->noinstr &&
!strncmp(insn->call_dest->name, "__sanitizer_cov_", 16)) {
if (reloc) {
reloc->type = R_NONE;
elf_write_reloc(file->elf, reloc);
}
elf_write_insn(file->elf, insn->sec,
insn->offset, insn->len,
arch_nop_insn(insn->len));
insn->type = INSN_NOP;
}
if (mcount && !strcmp(insn->call_dest->name, "__fentry__")) {
if (reloc) {
reloc->type = R_NONE;
elf_write_reloc(file->elf, reloc);
}
elf_write_insn(file->elf, insn->sec,
insn->offset, insn->len,
arch_nop_insn(insn->len));
insn->type = INSN_NOP;
list_add_tail(&insn->mcount_loc_node,
&file->mcount_loc_list);
}
/*
* Whatever stack impact regular CALLs have, should be undone
* by the RETURN of the called function.
*
* Annotated intra-function calls retain the stack_ops but
* are converted to JUMP, see read_intra_function_calls().
*/
remove_insn_ops(insn);
add_call_dest(file, insn, reloc->sym, false);
}
return 0;
@ -1136,7 +1381,6 @@ static int handle_group_alt(struct objtool_file *file,
memset(nop, 0, sizeof(*nop));
INIT_LIST_HEAD(&nop->alts);
INIT_LIST_HEAD(&nop->stack_ops);
init_cfi_state(&nop->cfi);
nop->sec = special_alt->new_sec;
nop->offset = special_alt->new_off + special_alt->new_len;
@ -1545,10 +1789,11 @@ static void set_func_state(struct cfi_state *state)
static int read_unwind_hints(struct objtool_file *file)
{
struct cfi_state cfi = init_cfi;
struct section *sec, *relocsec;
struct reloc *reloc;
struct unwind_hint *hint;
struct instruction *insn;
struct reloc *reloc;
int i;
sec = find_section_by_name(file->elf, ".discard.unwind_hints");
@ -1586,19 +1831,24 @@ static int read_unwind_hints(struct objtool_file *file)
insn->hint = true;
if (hint->type == UNWIND_HINT_TYPE_FUNC) {
set_func_state(&insn->cfi);
insn->cfi = &func_cfi;
continue;
}
if (arch_decode_hint_reg(insn, hint->sp_reg)) {
if (insn->cfi)
cfi = *(insn->cfi);
if (arch_decode_hint_reg(hint->sp_reg, &cfi.cfa.base)) {
WARN_FUNC("unsupported unwind_hint sp base reg %d",
insn->sec, insn->offset, hint->sp_reg);
return -1;
}
insn->cfi.cfa.offset = bswap_if_needed(hint->sp_offset);
insn->cfi.type = hint->type;
insn->cfi.end = hint->end;
cfi.cfa.offset = bswap_if_needed(hint->sp_offset);
cfi.type = hint->type;
cfi.end = hint->end;
insn->cfi = cfi_hash_find_or_add(&cfi);
}
return 0;
@ -1737,17 +1987,28 @@ static int read_intra_function_calls(struct objtool_file *file)
return 0;
}
static int read_static_call_tramps(struct objtool_file *file)
static int classify_symbols(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;
for_each_sec(file, sec) {
list_for_each_entry(func, &sec->symbol_list, list) {
if (func->bind == STB_GLOBAL &&
!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
if (func->bind != STB_GLOBAL)
continue;
if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
func->static_call_tramp = true;
if (arch_is_retpoline(func))
func->retpoline_thunk = true;
if (!strcmp(func->name, "__fentry__"))
func->fentry = true;
if (!strncmp(func->name, "__sanitizer_cov_", 16))
func->kcov = true;
}
}
@ -1780,17 +2041,16 @@ static void mark_rodata(struct objtool_file *file)
file->rodata = found;
}
__weak int arch_rewrite_retpolines(struct objtool_file *file)
{
return 0;
}
static int decode_sections(struct objtool_file *file)
{
int ret;
mark_rodata(file);
ret = init_pv_ops(file);
if (ret)
return ret;
ret = decode_instructions(file);
if (ret)
return ret;
@ -1809,7 +2069,7 @@ static int decode_sections(struct objtool_file *file)
/*
* Must be before add_{jump_call}_destination.
*/
ret = read_static_call_tramps(file);
ret = classify_symbols(file);
if (ret)
return ret;
@ -1853,23 +2113,14 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
/*
* Must be after add_special_section_alts(), since this will emit
* alternatives. Must be after add_{jump,call}_destination(), since
* those create the call insn lists.
*/
ret = arch_rewrite_retpolines(file);
if (ret)
return ret;
return 0;
}
static bool is_fentry_call(struct instruction *insn)
{
if (insn->type == INSN_CALL && insn->call_dest &&
insn->call_dest->type == STT_NOTYPE &&
!strcmp(insn->call_dest->name, "__fentry__"))
if (insn->type == INSN_CALL &&
insn->call_dest &&
insn->call_dest->fentry)
return true;
return false;
@ -2452,13 +2703,18 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn
if (!insn->alt_group)
return 0;
if (!insn->cfi) {
WARN("CFI missing");
return -1;
}
alt_cfi = insn->alt_group->cfi;
group_off = insn->offset - insn->alt_group->first_insn->offset;
if (!alt_cfi[group_off]) {
alt_cfi[group_off] = &insn->cfi;
alt_cfi[group_off] = insn->cfi;
} else {
if (memcmp(alt_cfi[group_off], &insn->cfi, sizeof(struct cfi_state))) {
if (cficmp(alt_cfi[group_off], insn->cfi)) {
WARN_FUNC("stack layout conflict in alternatives",
insn->sec, insn->offset);
return -1;
@ -2509,9 +2765,14 @@ static int handle_insn_ops(struct instruction *insn,
static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
{
struct cfi_state *cfi1 = &insn->cfi;
struct cfi_state *cfi1 = insn->cfi;
int i;
if (!cfi1) {
WARN("CFI missing");
return false;
}
if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) {
WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
@ -2562,20 +2823,64 @@ static inline bool func_uaccess_safe(struct symbol *func)
static inline const char *call_dest_name(struct instruction *insn)
{
static char pvname[16];
struct reloc *rel;
int idx;
if (insn->call_dest)
return insn->call_dest->name;
rel = insn_reloc(NULL, insn);
if (rel && !strcmp(rel->sym->name, "pv_ops")) {
idx = (rel->addend / sizeof(void *));
snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx);
return pvname;
}
return "{dynamic}";
}
static inline bool noinstr_call_dest(struct symbol *func)
static bool pv_call_dest(struct objtool_file *file, struct instruction *insn)
{
struct symbol *target;
struct reloc *rel;
int idx;
rel = insn_reloc(file, insn);
if (!rel || strcmp(rel->sym->name, "pv_ops"))
return false;
idx = (arch_dest_reloc_offset(rel->addend) / sizeof(void *));
if (file->pv_ops[idx].clean)
return true;
file->pv_ops[idx].clean = true;
list_for_each_entry(target, &file->pv_ops[idx].targets, pv_target) {
if (!target->sec->noinstr) {
WARN("pv_ops[%d]: %s", idx, target->name);
file->pv_ops[idx].clean = false;
}
}
return file->pv_ops[idx].clean;
}
static inline bool noinstr_call_dest(struct objtool_file *file,
struct instruction *insn,
struct symbol *func)
{
/*
* We can't deal with indirect function calls at present;
* assume they're instrumented.
*/
if (!func)
if (!func) {
if (file->pv_ops)
return pv_call_dest(file, insn);
return false;
}
/*
* If the symbol is from a noinstr section; we good.
@ -2594,10 +2899,12 @@ static inline bool noinstr_call_dest(struct symbol *func)
return false;
}
static int validate_call(struct instruction *insn, struct insn_state *state)
static int validate_call(struct objtool_file *file,
struct instruction *insn,
struct insn_state *state)
{
if (state->noinstr && state->instr <= 0 &&
!noinstr_call_dest(insn->call_dest)) {
!noinstr_call_dest(file, insn, insn->call_dest)) {
WARN_FUNC("call to %s() leaves .noinstr.text section",
insn->sec, insn->offset, call_dest_name(insn));
return 1;
@ -2618,7 +2925,9 @@ static int validate_call(struct instruction *insn, struct insn_state *state)
return 0;
}
static int validate_sibling_call(struct instruction *insn, struct insn_state *state)
static int validate_sibling_call(struct objtool_file *file,
struct instruction *insn,
struct insn_state *state)
{
if (has_modified_stack_frame(insn, state)) {
WARN_FUNC("sibling call from callable instruction with modified stack frame",
@ -2626,7 +2935,7 @@ static int validate_sibling_call(struct instruction *insn, struct insn_state *st
return 1;
}
return validate_call(insn, state);
return validate_call(file, insn, state);
}
static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state)
@ -2696,7 +3005,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
struct instruction *insn, struct insn_state state)
{
struct alternative *alt;
struct instruction *next_insn;
struct instruction *next_insn, *prev_insn = NULL;
struct section *sec;
u8 visited;
int ret;
@ -2725,15 +3034,25 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
if (insn->visited & visited)
return 0;
} else {
nr_insns_visited++;
}
if (state.noinstr)
state.instr += insn->instr;
if (insn->hint)
state.cfi = insn->cfi;
else
insn->cfi = state.cfi;
if (insn->hint) {
state.cfi = *insn->cfi;
} else {
/* XXX track if we actually changed state.cfi */
if (prev_insn && !cficmp(prev_insn->cfi, &state.cfi)) {
insn->cfi = prev_insn->cfi;
nr_cfi_reused++;
} else {
insn->cfi = cfi_hash_find_or_add(&state.cfi);
}
}
insn->visited |= visited;
@ -2769,7 +3088,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_CALL:
case INSN_CALL_DYNAMIC:
ret = validate_call(insn, &state);
ret = validate_call(file, insn, &state);
if (ret)
return ret;
@ -2788,7 +3107,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
ret = validate_sibling_call(file, insn, &state);
if (ret)
return ret;
@ -2810,7 +3129,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
case INSN_JUMP_DYNAMIC:
case INSN_JUMP_DYNAMIC_CONDITIONAL:
if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
ret = validate_sibling_call(file, insn, &state);
if (ret)
return ret;
}
@ -2883,6 +3202,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
return 1;
}
prev_insn = insn;
insn = next_insn;
}
@ -3138,10 +3458,20 @@ int check(struct objtool_file *file)
int ret, warnings = 0;
arch_initial_func_cfi_state(&initial_func_cfi);
init_cfi_state(&init_cfi);
init_cfi_state(&func_cfi);
set_func_state(&func_cfi);
if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3)))
goto out;
cfi_hash_add(&init_cfi);
cfi_hash_add(&func_cfi);
ret = decode_sections(file);
if (ret < 0)
goto out;
warnings += ret;
if (list_empty(&file->insn_list))
@ -3185,6 +3515,13 @@ int check(struct objtool_file *file)
goto out;
warnings += ret;
if (retpoline) {
ret = create_retpoline_sites_sections(file);
if (ret < 0)
goto out;
warnings += ret;
}
if (mcount) {
ret = create_mcount_loc_sections(file);
if (ret < 0)
@ -3192,6 +3529,13 @@ int check(struct objtool_file *file)
warnings += ret;
}
if (stats) {
printf("nr_insns_visited: %ld\n", nr_insns_visited);
printf("nr_cfi: %ld\n", nr_cfi);
printf("nr_cfi_reused: %ld\n", nr_cfi_reused);
printf("nr_cfi_cache: %ld\n", nr_cfi_cache);
}
out:
/*
* For now, don't fail the kernel build on fatal warnings. These

84
tools/objtool/elf.c
View File

@ -741,90 +741,6 @@ static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
return len;
}
struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name)
{
struct section *symtab, *symtab_shndx;
struct symbol *sym;
Elf_Data *data;
Elf_Scn *s;
sym = malloc(sizeof(*sym));
if (!sym) {
perror("malloc");
return NULL;
}
memset(sym, 0, sizeof(*sym));
sym->name = strdup(name);
sym->sym.st_name = elf_add_string(elf, NULL, sym->name);
if (sym->sym.st_name == -1)
return NULL;
sym->sym.st_info = GELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
// st_other 0
// st_shndx 0
// st_value 0
// st_size 0
symtab = find_section_by_name(elf, ".symtab");
if (!symtab) {
WARN("can't find .symtab");
return NULL;
}
s = elf_getscn(elf->elf, symtab->idx);
if (!s) {
WARN_ELF("elf_getscn");
return NULL;
}
data = elf_newdata(s);
if (!data) {
WARN_ELF("elf_newdata");
return NULL;
}
data->d_buf = &sym->sym;
data->d_size = sizeof(sym->sym);
data->d_align = 1;
data->d_type = ELF_T_SYM;
sym->idx = symtab->sh.sh_size / sizeof(sym->sym);
symtab->sh.sh_size += data->d_size;
symtab->changed = true;
symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
if (symtab_shndx) {
s = elf_getscn(elf->elf, symtab_shndx->idx);
if (!s) {
WARN_ELF("elf_getscn");
return NULL;
}
data = elf_newdata(s);
if (!data) {
WARN_ELF("elf_newdata");
return NULL;
}
data->d_buf = &sym->sym.st_size; /* conveniently 0 */
data->d_size = sizeof(Elf32_Word);
data->d_align = 4;
data->d_type = ELF_T_WORD;
symtab_shndx->sh.sh_size += 4;
symtab_shndx->changed = true;
}
sym->sec = find_section_by_index(elf, 0);
elf_add_symbol(elf, sym);
return sym;
}
struct section *elf_create_section(struct elf *elf, const char *name,
unsigned int sh_flags, size_t entsize, int nr)
{

5
tools/objtool/include/objtool/arch.h
View File

@ -69,7 +69,7 @@ struct instruction;
void arch_initial_func_cfi_state(struct cfi_init_state *state);
int arch_decode_instruction(const struct elf *elf, const struct section *sec,
int arch_decode_instruction(struct objtool_file *file, const struct section *sec,
unsigned long offset, unsigned int maxlen,
unsigned int *len, enum insn_type *type,
unsigned long *immediate,
@ -82,8 +82,9 @@ unsigned long arch_jump_destination(struct instruction *insn);
unsigned long arch_dest_reloc_offset(int addend);
const char *arch_nop_insn(int len);
const char *arch_ret_insn(int len);
int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg);
int arch_decode_hint_reg(u8 sp_reg, int *base);
bool arch_is_retpoline(struct symbol *sym);

2
tools/objtool/include/objtool/cfi.h
View File

@ -7,6 +7,7 @@
#define _OBJTOOL_CFI_H
#include <arch/cfi_regs.h>
#include <linux/list.h>
#define CFI_UNDEFINED -1
#define CFI_CFA -2
@ -24,6 +25,7 @@ struct cfi_init_state {
};
struct cfi_state {
struct hlist_node hash; /* must be first, cficmp() */
struct cfi_reg regs[CFI_NUM_REGS];
struct cfi_reg vals[CFI_NUM_REGS];
struct cfi_reg cfa;

3
tools/objtool/include/objtool/check.h
View File

@ -40,7 +40,6 @@ struct instruction {
struct list_head list;
struct hlist_node hash;
struct list_head call_node;
struct list_head mcount_loc_node;
struct section *sec;
unsigned long offset;
unsigned int len;
@ -60,7 +59,7 @@ struct instruction {
struct list_head alts;
struct symbol *func;
struct list_head stack_ops;
struct cfi_state cfi;
struct cfi_state *cfi;
};
static inline bool is_static_jump(struct instruction *insn)

9
tools/objtool/include/objtool/elf.h
View File

@ -54,8 +54,12 @@ struct symbol {
unsigned long offset;
unsigned int len;
struct symbol *pfunc, *cfunc, *alias;
bool uaccess_safe;
bool static_call_tramp;
u8 uaccess_safe : 1;
u8 static_call_tramp : 1;
u8 retpoline_thunk : 1;
u8 fentry : 1;
u8 kcov : 1;
struct list_head pv_target;
};
struct reloc {
@ -140,7 +144,6 @@ int elf_write_insn(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int len,
const char *insn);
int elf_write_reloc(struct elf *elf, struct reloc *reloc);
struct symbol *elf_create_undef_symbol(struct elf *elf, const char *name);
int elf_write(struct elf *elf);
void elf_close(struct elf *elf);

9
tools/objtool/include/objtool/objtool.h
View File

@ -14,6 +14,11 @@
#define __weak __attribute__((weak))
struct pv_state {
bool clean;
struct list_head targets;
};
struct objtool_file {
struct elf *elf;
struct list_head insn_list;
@ -25,10 +30,14 @@ struct objtool_file {
unsigned long jl_short, jl_long;
unsigned long jl_nop_short, jl_nop_long;
struct pv_state *pv_ops;
};
struct objtool_file *objtool_open_read(const char *_objname);
void objtool_pv_add(struct objtool_file *file, int idx, struct symbol *func);
int check(struct objtool_file *file);
int orc_dump(const char *objname);
int orc_create(struct objtool_file *file);

22
tools/objtool/objtool.c
View File

@ -135,6 +135,28 @@ struct objtool_file *objtool_open_read(const char *_objname)
return &file;
}
void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func)
{
if (!noinstr)
return;
if (!f->pv_ops) {
WARN("paravirt confusion");
return;
}
/*
* These functions will be patched into native code,
* see paravirt_patch().
*/
if (!strcmp(func->name, "_paravirt_nop") ||
!strcmp(func->name, "_paravirt_ident_64"))
return;
list_add(&func->pv_target, &f->pv_ops[idx].targets);
f->pv_ops[idx].clean = false;
}
static void cmd_usage(void)
{
unsigned int i, longest = 0;

15
tools/objtool/orc_gen.c
View File

@ -13,13 +13,19 @@
#include <objtool/warn.h>
#include <objtool/endianness.h>
static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi)
static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
struct instruction *insn)
{
struct instruction *insn = container_of(cfi, struct instruction, cfi);
struct cfi_reg *bp = &cfi->regs[CFI_BP];
memset(orc, 0, sizeof(*orc));
if (!cfi) {
orc->end = 0;
orc->sp_reg = ORC_REG_UNDEFINED;
return 0;
}
orc->end = cfi->end;
if (cfi->cfa.base == CFI_UNDEFINED) {
@ -162,7 +168,7 @@ int orc_create(struct objtool_file *file)
int i;
if (!alt_group) {
if (init_orc_entry(&orc, &insn->cfi))
if (init_orc_entry(&orc, insn->cfi, insn))
return -1;
if (!memcmp(&prev_orc, &orc, sizeof(orc)))
continue;
@ -186,7 +192,8 @@ int orc_create(struct objtool_file *file)
struct cfi_state *cfi = alt_group->cfi[i];
if (!cfi)
continue;
if (init_orc_entry(&orc, cfi))
/* errors are reported on the original insn */
if (init_orc_entry(&orc, cfi, insn))
return -1;
if (!memcmp(&prev_orc, &orc, sizeof(orc)))
continue;

8
tools/objtool/special.c
View File

@ -109,14 +109,6 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
return -1;
}
/*
* Skip retpoline .altinstr_replacement... we already rewrite the
* instructions for retpolines anyway, see arch_is_retpoline()
* usage in add_{call,jump}_destinations().
*/
if (arch_is_retpoline(new_reloc->sym))
return 1;
reloc_to_sec_off(new_reloc, &alt->new_sec, &alt->new_off);
/* _ASM_EXTABLE_EX hack */