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Merge tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

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Pull x86 CET-IBT (Control-Flow-Integrity) support from Peter Zijlstra:
 "Add support for Intel CET-IBT, available since Tigerlake (11th gen),
  which is a coarse grained, hardware based, forward edge
  Control-Flow-Integrity mechanism where any indirect CALL/JMP must
  target an ENDBR instruction or suffer #CP.

  Additionally, since Alderlake (12th gen)/Sapphire-Rapids, speculation
  is limited to 2 instructions (and typically fewer) on branch targets
  not starting with ENDBR. CET-IBT also limits speculation of the next
  sequential instruction after the indirect CALL/JMP [1].

  CET-IBT is fundamentally incompatible with retpolines, but provides,
  as described above, speculation limits itself"

[1] https://www.intel.com/content/www/us/en/developer/articles/technical/software-security-guidance/technical-documentation/branch-history-injection.html

* tag 'x86_core_for_5.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  kvm/emulate: Fix SETcc emulation for ENDBR
  x86/Kconfig: Only allow CONFIG_X86_KERNEL_IBT with ld.lld >= 14.0.0
  x86/Kconfig: Only enable CONFIG_CC_HAS_IBT for clang >= 14.0.0
  kbuild: Fixup the IBT kbuild changes
  x86/Kconfig: Do not allow CONFIG_X86_X32_ABI=y with llvm-objcopy
  x86: Remove toolchain check for X32 ABI capability
  x86/alternative: Use .ibt_endbr_seal to seal indirect calls
  objtool: Find unused ENDBR instructions
  objtool: Validate IBT assumptions
  objtool: Add IBT/ENDBR decoding
  objtool: Read the NOENDBR annotation
  x86: Annotate idtentry_df()
  x86,objtool: Move the ASM_REACHABLE annotation to objtool.h
  x86: Annotate call_on_stack()
  objtool: Rework ASM_REACHABLE
  x86: Mark __invalid_creds() __noreturn
  exit: Mark do_group_exit() __noreturn
  x86: Mark stop_this_cpu() __noreturn
  objtool: Ignore extra-symbol code
  objtool: Rename --duplicate to --lto
  ...
This commit is contained in:
Linus Torvalds
2022-03-27 10:17:23 -07:00
parent f022814633 3986f65d4f
commit 7001052160
95 changed files with 1462 additions and 334 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/bpf/trampoline.c
+4 -16
View File
@@ -117,18 +117,6 @@ static void bpf_trampoline_module_put(struct bpf_trampoline *tr)
tr->mod = NULL;
}
static int is_ftrace_location(void *ip)
{
long addr;
addr = ftrace_location((long)ip);
if (!addr)
return 0;
if (WARN_ON_ONCE(addr != (long)ip))
return -EFAULT;
return 1;
}
static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr)
{
void *ip = tr->func.addr;
@@ -160,12 +148,12 @@ static int modify_fentry(struct bpf_trampoline *tr, void *old_addr, void *new_ad
static int register_fentry(struct bpf_trampoline *tr, void *new_addr)
{
void *ip = tr->func.addr;
unsigned long faddr;
int ret;
ret = is_ftrace_location(ip);
if (ret < 0)
return ret;
tr->func.ftrace_managed = ret;
faddr = ftrace_location((unsigned long)ip);
if (faddr)
tr->func.ftrace_managed = true;
if (bpf_trampoline_module_get(tr))
return -ENOENT;
kernel/cred.c
+1 -1
View File
@@ -870,7 +870,7 @@ static void dump_invalid_creds(const struct cred *cred, const char *label,
/*
* report use of invalid credentials
*/
void __invalid_creds(const struct cred *cred, const char *file, unsigned line)
void __noreturn __invalid_creds(const struct cred *cred, const char *file, unsigned line)
{
printk(KERN_ERR "CRED: Invalid credentials\n");
printk(KERN_ERR "CRED: At %s:%u\n", file, line);
kernel/exit.c
+1 -1
View File
@@ -895,7 +895,7 @@ SYSCALL_DEFINE1(exit, int, error_code)
* Take down every thread in the group. This is called by fatal signals
* as well as by sys_exit_group (below).
*/
void
void __noreturn
do_group_exit(int exit_code)
{
struct signal_struct *sig = current->signal;
kernel/kprobes.c
+54 -20
View File
@@ -1488,25 +1488,69 @@ bool within_kprobe_blacklist(unsigned long addr)
return false;
}
/*
* arch_adjust_kprobe_addr - adjust the address
* @addr: symbol base address
* @offset: offset within the symbol
* @on_func_entry: was this @addr+@offset on the function entry
*
* Typically returns @addr + @offset, except for special cases where the
* function might be prefixed by a CFI landing pad, in that case any offset
* inside the landing pad is mapped to the first 'real' instruction of the
* symbol.
*
* Specifically, for things like IBT/BTI, skip the resp. ENDBR/BTI.C
* instruction at +0.
*/
kprobe_opcode_t *__weak arch_adjust_kprobe_addr(unsigned long addr,
unsigned long offset,
bool *on_func_entry)
{
*on_func_entry = !offset;
return (kprobe_opcode_t *)(addr + offset);
}
/*
* If 'symbol_name' is specified, look it up and add the 'offset'
* to it. This way, we can specify a relative address to a symbol.
* This returns encoded errors if it fails to look up symbol or invalid
* combination of parameters.
*/
static kprobe_opcode_t *_kprobe_addr(kprobe_opcode_t *addr,
const char *symbol_name, unsigned int offset)
static kprobe_opcode_t *
_kprobe_addr(kprobe_opcode_t *addr, const char *symbol_name,
unsigned long offset, bool *on_func_entry)
{
if ((symbol_name && addr) || (!symbol_name && !addr))
goto invalid;
if (symbol_name) {
/*
* Input: @sym + @offset
* Output: @addr + @offset
*
* NOTE: kprobe_lookup_name() does *NOT* fold the offset
* argument into it's output!
*/
addr = kprobe_lookup_name(symbol_name, offset);
if (!addr)
return ERR_PTR(-ENOENT);
}
addr = (kprobe_opcode_t *)(((char *)addr) + offset);
/*
* So here we have @addr + @offset, displace it into a new
* @addr' + @offset' where @addr' is the symbol start address.
*/
addr = (void *)addr + offset;
if (!kallsyms_lookup_size_offset((unsigned long)addr, NULL, &offset))
return ERR_PTR(-ENOENT);
addr = (void *)addr - offset;
/*
* Then ask the architecture to re-combine them, taking care of
* magical function entry details while telling us if this was indeed
* at the start of the function.
*/
addr = arch_adjust_kprobe_addr((unsigned long)addr, offset, on_func_entry);
if (addr)
return addr;
@@ -1516,7 +1560,8 @@ invalid:
static kprobe_opcode_t *kprobe_addr(struct kprobe *p)
{
return _kprobe_addr(p->addr, p->symbol_name, p->offset);
bool on_func_entry;
return _kprobe_addr(p->addr, p->symbol_name, p->offset, &on_func_entry);
}
/*
@@ -1562,14 +1607,10 @@ static inline int warn_kprobe_rereg(struct kprobe *p)
static int check_ftrace_location(struct kprobe *p)
{
unsigned long ftrace_addr;
unsigned long addr = (unsigned long)p->addr;
ftrace_addr = ftrace_location((unsigned long)p->addr);
if (ftrace_addr) {
if (ftrace_location(addr) == addr) {
#ifdef CONFIG_KPROBES_ON_FTRACE
/* Given address is not on the instruction boundary */
if ((unsigned long)p->addr != ftrace_addr)
return -EILSEQ;
p->flags |= KPROBE_FLAG_FTRACE;
#else /* !CONFIG_KPROBES_ON_FTRACE */
return -EINVAL;
@@ -2047,11 +2088,6 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs)
}
NOKPROBE_SYMBOL(pre_handler_kretprobe);
bool __weak arch_kprobe_on_func_entry(unsigned long offset)
{
return !offset;
}
/**
* kprobe_on_func_entry() -- check whether given address is function entry
* @addr: Target address
@@ -2067,15 +2103,13 @@ bool __weak arch_kprobe_on_func_entry(unsigned long offset)
*/
int kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset)
{
kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset);
bool on_func_entry;
kprobe_opcode_t *kp_addr = _kprobe_addr(addr, sym, offset, &on_func_entry);
if (IS_ERR(kp_addr))
return PTR_ERR(kp_addr);
if (!kallsyms_lookup_size_offset((unsigned long)kp_addr, NULL, &offset))
return -ENOENT;
if (!arch_kprobe_on_func_entry(offset))
if (!on_func_entry)
return -EINVAL;
return 0;
kernel/livepatch/patch.c
+2 -17
View File
@@ -124,19 +124,6 @@ unlock:
ftrace_test_recursion_unlock(bit);
}
/*
* Convert a function address into the appropriate ftrace location.
*
* Usually this is just the address of the function, but on some architectures
* it's more complicated so allow them to provide a custom behaviour.
*/
#ifndef klp_get_ftrace_location
static unsigned long klp_get_ftrace_location(unsigned long faddr)
{
return faddr;
}
#endif
static void klp_unpatch_func(struct klp_func *func)
{
struct klp_ops *ops;
@@ -153,8 +140,7 @@ static void klp_unpatch_func(struct klp_func *func)
if (list_is_singular(&ops->func_stack)) {
unsigned long ftrace_loc;
ftrace_loc =
klp_get_ftrace_location((unsigned long)func->old_func);
ftrace_loc = ftrace_location((unsigned long)func->old_func);
if (WARN_ON(!ftrace_loc))
return;
@@ -186,8 +172,7 @@ static int klp_patch_func(struct klp_func *func)
if (!ops) {
unsigned long ftrace_loc;
ftrace_loc =
klp_get_ftrace_location((unsigned long)func->old_func);
ftrace_loc = ftrace_location((unsigned long)func->old_func);
if (!ftrace_loc) {
pr_err("failed to find location for function '%s'\n",
func->old_name);
kernel/trace/ftrace.c
+40 -8
View File
@@ -1568,17 +1568,34 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
}
/**
* ftrace_location - return true if the ip giving is a traced location
* ftrace_location - return the ftrace location
* @ip: the instruction pointer to check
*
* Returns rec->ip if @ip given is a pointer to a ftrace location.
* That is, the instruction that is either a NOP or call to
* the function tracer. It checks the ftrace internal tables to
* determine if the address belongs or not.
* If @ip matches the ftrace location, return @ip.
* If @ip matches sym+0, return sym's ftrace location.
* Otherwise, return 0.
*/
unsigned long ftrace_location(unsigned long ip)
{
return ftrace_location_range(ip, ip);
struct dyn_ftrace *rec;
unsigned long offset;
unsigned long size;
rec = lookup_rec(ip, ip);
if (!rec) {
if (!kallsyms_lookup_size_offset(ip, &size, &offset))
goto out;
/* map sym+0 to __fentry__ */
if (!offset)
rec = lookup_rec(ip, ip + size - 1);
}
if (rec)
return rec->ip;
out:
return 0;
}
/**
@@ -4962,7 +4979,8 @@ __ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
{
struct ftrace_func_entry *entry;
if (!ftrace_location(ip))
ip = ftrace_location(ip);
if (!ip)
return -EINVAL;
if (remove) {
@@ -5131,11 +5149,16 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
struct ftrace_func_entry *entry;
struct ftrace_hash *free_hash = NULL;
struct dyn_ftrace *rec;
int ret = -EBUSY;
int ret = -ENODEV;
mutex_lock(&direct_mutex);
ip = ftrace_location(ip);
if (!ip)
goto out_unlock;
/* See if there's a direct function at @ip already */
ret = -EBUSY;
if (ftrace_find_rec_direct(ip))
goto out_unlock;
@@ -5243,6 +5266,10 @@ int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
mutex_lock(&direct_mutex);
ip = ftrace_location(ip);
if (!ip)
goto out_unlock;
entry = find_direct_entry(&ip, NULL);
if (!entry)
goto out_unlock;
@@ -5375,6 +5402,11 @@ int modify_ftrace_direct(unsigned long ip,
mutex_lock(&direct_mutex);
mutex_lock(&ftrace_lock);
ip = ftrace_location(ip);
if (!ip)
goto out_unlock;
entry = find_direct_entry(&ip, &rec);
if (!entry)
goto out_unlock;