Pull livepatching support for ppc64 architecture from Michael Ellerman.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
select OF_RESERVED_MEM
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
+ select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select SYSCTL_EXCEPTION_TRACE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select HAVE_ARCH_SECCOMP_FILTER
select ARCH_HAS_UBSAN_SANITIZE_ALL
+ select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
---help---
Support user-mode Transactional Memory on POWERPC.
+ config DISABLE_MPROFILE_KERNEL
+ bool "Disable use of mprofile-kernel for kernel tracing"
+ depends on PPC64 && CPU_LITTLE_ENDIAN
+ default y
+ help
+ Selecting this options disables use of the mprofile-kernel ABI for
+ kernel tracing. That will cause options such as live patching
+ (CONFIG_LIVEPATCH) which depend on CONFIG_DYNAMIC_FTRACE_WITH_REGS to
+ be disabled also.
+
+ If you have a toolchain which supports mprofile-kernel, then you can
+ enable this. Otherwise leave it disabled. If you're not sure, say
+ "N".
+
+ config MPROFILE_KERNEL
+ depends on PPC64 && CPU_LITTLE_ENDIAN
+ def_bool !DISABLE_MPROFILE_KERNEL
+
config IOMMU_HELPER
def_bool PPC64
config PPC_4K_PAGES
bool "4k page size"
- select HAVE_ARCH_SOFT_DIRTY if CHECKPOINT_RESTORE && PPC_BOOK3S
+ select HAVE_ARCH_SOFT_DIRTY if PPC_BOOK3S_64
config PPC_16K_PAGES
bool "16k page size"
config PPC_64K_PAGES
bool "64k page size"
depends on !PPC_FSL_BOOK3E && (44x || PPC_STD_MMU_64 || PPC_BOOK3E_64)
- select HAVE_ARCH_SOFT_DIRTY if CHECKPOINT_RESTORE && PPC_BOOK3S
+ select HAVE_ARCH_SOFT_DIRTY if PPC_BOOK3S_64
config PPC_256K_PAGES
bool "256k page size"
select PPC_INDIRECT_PCI
default y
-source "drivers/pci/pcie/Kconfig"
-
source "drivers/pci/Kconfig"
source "drivers/pcmcia/Kconfig"
-source "drivers/pci/hotplug/Kconfig"
-
config HAS_RAPIDIO
bool
default n
bool
source "arch/powerpc/kvm/Kconfig"
+
+ source "kernel/livepatch/Kconfig"
#include <asm/code-patching.h>
#include <linux/sort.h>
#include <asm/setup.h>
+ #include <asm/sections.h>
/* FIXME: We don't do .init separately. To do this, we'd need to have
a separate r2 value in the init and core section, and stub between
--RR. */
#if defined(_CALL_ELF) && _CALL_ELF == 2
- #define R2_STACK_OFFSET 24
/* An address is simply the address of the function. */
typedef unsigned long func_desc_t;
return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
}
#else
- #define R2_STACK_OFFSET 40
/* An address is address of the OPD entry, which contains address of fn. */
typedef struct ppc64_opd_entry func_desc_t;
}
#endif
+ #define STUB_MAGIC 0x73747562 /* stub */
+
/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
the kernel itself). But on PPC64, these need to be used for every
jump, actually, to reset r2 (TOC+0x8000). */
* need 6 instructions on ABIv2 but we always allocate 7 so
* so we don't have to modify the trampoline load instruction. */
u32 jump[7];
- u32 unused;
+ /* Used by ftrace to identify stubs */
+ u32 magic;
/* Data for the above code */
func_desc_t funcdata;
};
};
#ifdef CONFIG_DYNAMIC_FTRACE
-
- static u32 ppc64_stub_mask[] = {
- 0xffff0000,
- 0xffff0000,
- 0xffffffff,
- 0xffffffff,
- #if !defined(_CALL_ELF) || _CALL_ELF != 2
- 0xffffffff,
- #endif
- 0xffffffff,
- 0xffffffff
- };
-
- bool is_module_trampoline(u32 *p)
+ int module_trampoline_target(struct module *mod, unsigned long addr,
+ unsigned long *target)
{
- unsigned int i;
- u32 insns[ARRAY_SIZE(ppc64_stub_insns)];
-
- BUILD_BUG_ON(sizeof(ppc64_stub_insns) != sizeof(ppc64_stub_mask));
+ struct ppc64_stub_entry *stub;
+ func_desc_t funcdata;
+ u32 magic;
- if (probe_kernel_read(insns, p, sizeof(insns)))
+ if (!within_module_core(addr, mod)) {
+ pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name);
return -EFAULT;
-
- for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) {
- u32 insna = insns[i];
- u32 insnb = ppc64_stub_insns[i];
- u32 mask = ppc64_stub_mask[i];
-
- if ((insna & mask) != (insnb & mask))
- return false;
}
- return true;
- }
-
- int module_trampoline_target(struct module *mod, u32 *trampoline,
- unsigned long *target)
- {
- u32 buf[2];
- u16 upper, lower;
- long offset;
- void *toc_entry;
+ stub = (struct ppc64_stub_entry *)addr;
- if (probe_kernel_read(buf, trampoline, sizeof(buf)))
+ if (probe_kernel_read(&magic, &stub->magic, sizeof(magic))) {
+ pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name);
return -EFAULT;
+ }
- upper = buf[0] & 0xffff;
- lower = buf[1] & 0xffff;
-
- /* perform the addis/addi, both signed */
- offset = ((short)upper << 16) + (short)lower;
+ if (magic != STUB_MAGIC) {
+ pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
- /*
- * Now get the address this trampoline jumps to. This
- * is always 32 bytes into our trampoline stub.
- */
- toc_entry = (void *)mod->arch.toc + offset + 32;
+ if (probe_kernel_read(&funcdata, &stub->funcdata, sizeof(funcdata))) {
+ pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name);
+ return -EFAULT;
+ }
- if (probe_kernel_read(target, toc_entry, sizeof(*target)))
- return -EFAULT;
+ *target = stub_func_addr(funcdata);
return 0;
}
-
#endif
/* Count how many different 24-bit relocations (different symbol,
if (name[0] == '.') {
if (strcmp(name+1, "TOC.") == 0)
syms[i].st_shndx = SHN_ABS;
- memmove(name, name+1, strlen(name));
+ syms[i].st_name++;
}
}
}
/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
gives the value maximum span in an instruction which uses a signed
offset) */
- static inline unsigned long my_r2(Elf64_Shdr *sechdrs, struct module *me)
+ static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me)
{
return sechdrs[me->arch.toc_section].sh_addr + 0x8000;
}
#define PPC_HA(v) PPC_HI ((v) + 0x8000)
/* Patch stub to reference function and correct r2 value. */
- static inline int create_stub(Elf64_Shdr *sechdrs,
+ static inline int create_stub(const Elf64_Shdr *sechdrs,
struct ppc64_stub_entry *entry,
unsigned long addr,
struct module *me)
entry->jump[0] |= PPC_HA(reladdr);
entry->jump[1] |= PPC_LO(reladdr);
entry->funcdata = func_desc(addr);
+ entry->magic = STUB_MAGIC;
+
return 1;
}
/* Create stub to jump to function described in this OPD/ptr: we need the
stub to set up the TOC ptr (r2) for the function. */
- static unsigned long stub_for_addr(Elf64_Shdr *sechdrs,
+ static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
unsigned long addr,
struct module *me)
{
return (unsigned long)&stubs[i];
}
+ #ifdef CC_USING_MPROFILE_KERNEL
+ static bool is_early_mcount_callsite(u32 *instruction)
+ {
+ /*
+ * Check if this is one of the -mprofile-kernel sequences.
+ */
+ if (instruction[-1] == PPC_INST_STD_LR &&
+ instruction[-2] == PPC_INST_MFLR)
+ return true;
+
+ if (instruction[-1] == PPC_INST_MFLR)
+ return true;
+
+ return false;
+ }
+
+ /*
+ * In case of _mcount calls, do not save the current callee's TOC (in r2) into
+ * the original caller's stack frame. If we did we would clobber the saved TOC
+ * value of the original caller.
+ */
+ static void squash_toc_save_inst(const char *name, unsigned long addr)
+ {
+ struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
+
+ /* Only for calls to _mcount */
+ if (strcmp("_mcount", name) != 0)
+ return;
+
+ stub->jump[2] = PPC_INST_NOP;
+ }
+ #else
+ static void squash_toc_save_inst(const char *name, unsigned long addr) { }
+
+ /* without -mprofile-kernel, mcount calls are never early */
+ static bool is_early_mcount_callsite(u32 *instruction)
+ {
+ return false;
+ }
+ #endif
+
/* We expect a noop next: if it is, replace it with instruction to
restore r2. */
static int restore_r2(u32 *instruction, struct module *me)
{
if (*instruction != PPC_INST_NOP) {
+ if (is_early_mcount_callsite(instruction - 1))
+ return 1;
pr_err("%s: Expect noop after relocate, got %08x\n",
me->name, *instruction);
return 0;
}
/* ld r2,R2_STACK_OFFSET(r1) */
- *instruction = 0xe8410000 | R2_STACK_OFFSET;
+ *instruction = PPC_INST_LD_TOC;
return 1;
}
return -ENOENT;
if (!restore_r2((u32 *)location + 1, me))
return -ENOEXEC;
+
+ squash_toc_save_inst(strtab + sym->st_name, value);
} else
value += local_entry_offset(sym);
}
}
+ return 0;
+ }
+
#ifdef CONFIG_DYNAMIC_FTRACE
- me->arch.toc = my_r2(sechdrs, me);
- me->arch.tramp = stub_for_addr(sechdrs,
- (unsigned long)ftrace_caller,
- me);
+
+ #ifdef CC_USING_MPROFILE_KERNEL
+
+ #define PACATOC offsetof(struct paca_struct, kernel_toc)
+
+ /*
+ * For mprofile-kernel we use a special stub for ftrace_caller() because we
+ * can't rely on r2 containing this module's TOC when we enter the stub.
+ *
+ * That can happen if the function calling us didn't need to use the toc. In
+ * that case it won't have setup r2, and the r2 value will be either the
+ * kernel's toc, or possibly another modules toc.
+ *
+ * To deal with that this stub uses the kernel toc, which is always accessible
+ * via the paca (in r13). The target (ftrace_caller()) is responsible for
+ * saving and restoring the toc before returning.
+ */
+ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me)
+ {
+ struct ppc64_stub_entry *entry;
+ unsigned int i, num_stubs;
+ static u32 stub_insns[] = {
+ 0xe98d0000 | PACATOC, /* ld r12,PACATOC(r13) */
+ 0x3d8c0000, /* addis r12,r12,<high> */
+ 0x398c0000, /* addi r12,r12,<low> */
+ 0x7d8903a6, /* mtctr r12 */
+ 0x4e800420, /* bctr */
+ };
+ long reladdr;
+
+ num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry);
+
+ /* Find the next available stub entry */
+ entry = (void *)sechdrs[me->arch.stubs_section].sh_addr;
+ for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++);
+
+ if (i >= num_stubs) {
+ pr_err("%s: Unable to find a free slot for ftrace stub.\n", me->name);
+ return 0;
+ }
+
+ memcpy(entry->jump, stub_insns, sizeof(stub_insns));
+
+ /* Stub uses address relative to kernel toc (from the paca) */
+ reladdr = (unsigned long)ftrace_caller - kernel_toc_addr();
+ if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
+ pr_err("%s: Address of ftrace_caller out of range of kernel_toc.\n", me->name);
+ return 0;
+ }
+
+ entry->jump[1] |= PPC_HA(reladdr);
+ entry->jump[2] |= PPC_LO(reladdr);
+
+ /* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */
+ entry->funcdata = func_desc((unsigned long)ftrace_caller);
+ entry->magic = STUB_MAGIC;
+
+ return (unsigned long)entry;
+ }
+ #else
+ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me)
+ {
+ return stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me);
+ }
#endif
+ int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
+ {
+ mod->arch.toc = my_r2(sechdrs, mod);
+ mod->arch.tramp = create_ftrace_stub(sechdrs, mod);
+
+ if (!mod->arch.tramp)
+ return -ENOENT;
+
return 0;
}
+ #endif
#include <asm/firmware.h>
#endif
#include <asm/code-patching.h>
+ #include <asm/livepatch.h>
+
#include <linux/kprobes.h>
#include <linux/kdebug.h>
extern void ret_from_kernel_thread(void);
void (*f)(void);
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+ struct thread_info *ti = task_thread_info(p);
+
+ klp_init_thread_info(ti);
/* Copy registers */
sp -= sizeof(struct pt_regs);
childregs = (struct pt_regs *) sp;
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
- struct thread_info *ti = (void *)task_stack_page(p);
memset(childregs, 0, sizeof(struct pt_regs));
childregs->gpr[1] = sp + sizeof(struct pt_regs);
/* function */
/* 8MB for 32bit, 1GB for 64bit */
if (is_32bit_task())
- rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
+ rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
else
- rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
+ rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
return rnd << PAGE_SHIFT;
}
#include <asm/kvm_ppc.h>
#include <asm/hugetlb.h>
#include <asm/epapr_hcalls.h>
+ #include <asm/livepatch.h>
#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
setup_paca(&boot_paca);
fixup_boot_paca();
- /* Initialize lockdep early or else spinlocks will blow */
- lockdep_init();
-
/* -------- printk is now safe to use ------- */
/* Enable early debugging if any specified (see udbg.h) */
limit = min(safe_stack_limit(), ppc64_rma_size);
for_each_possible_cpu(i) {
- unsigned long sp;
- sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
- sp += THREAD_SIZE;
- paca[i].emergency_sp = __va(sp);
+ struct thread_info *ti;
+ ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
+ klp_init_thread_info(ti);
+ paca[i].emergency_sp = (void *)ti + THREAD_SIZE;
#ifdef CONFIG_PPC_BOOK3S_64
/* emergency stack for machine check exception handling. */
- sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit);
- sp += THREAD_SIZE;
- paca[i].mc_emergency_sp = __va(sp);
+ ti = __va(memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit));
+ klp_init_thread_info(ti);
+ paca[i].mc_emergency_sp = (void *)ti + THREAD_SIZE;
#endif
}
}
if (ppc_md.panic)
setup_panic();
+ klp_init_thread_info(&init_thread_info);
+
init_mm.start_code = (unsigned long)_stext;
init_mm.end_code = (unsigned long) _etext;
init_mm.end_data = (unsigned long) _edata;
int ftrace_test_record(struct dyn_ftrace *rec, int enable);
void ftrace_run_stop_machine(int command);
unsigned long ftrace_location(unsigned long ip);
+ unsigned long ftrace_location_range(unsigned long start, unsigned long end);
unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
extern int skip_trace(unsigned long ip);
extern void ftrace_module_init(struct module *mod);
+extern void ftrace_module_enable(struct module *mod);
extern void ftrace_release_mod(struct module *mod);
extern void ftrace_disable_daemon(void);
static inline int ftrace_force_update(void) { return 0; }
static inline void ftrace_disable_daemon(void) { }
static inline void ftrace_enable_daemon(void) { }
-static inline void ftrace_release_mod(struct module *mod) {}
-static inline void ftrace_module_init(struct module *mod) {}
+static inline void ftrace_module_init(struct module *mod) { }
+static inline void ftrace_module_enable(struct module *mod) { }
+static inline void ftrace_release_mod(struct module *mod) { }
static inline __init int register_ftrace_command(struct ftrace_func_command *cmd)
{
return -EINVAL;
#define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
#define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
+static inline unsigned long get_lock_parent_ip(void)
+{
+ unsigned long addr = CALLER_ADDR0;
+
+ if (!in_lock_functions(addr))
+ return addr;
+ addr = CALLER_ADDR1;
+ if (!in_lock_functions(addr))
+ return addr;
+ return CALLER_ADDR2;
+}
+
#ifdef CONFIG_IRQSOFF_TRACER
extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
#include <linux/list.h>
#include <linux/kallsyms.h>
#include <linux/livepatch.h>
+#include <linux/elf.h>
+#include <linux/moduleloader.h>
#include <asm/cacheflush.h>
/**
/*
* We do not want to block removal of patched modules and therefore
* we do not take a reference here. The patches are removed by
- * a going module handler instead.
+ * klp_module_going() instead.
*/
mod = find_module(obj->name);
/*
- * Do not mess work of the module coming and going notifiers.
- * Note that the patch might still be needed before the going handler
+ * Do not mess work of klp_module_coming() and klp_module_going().
+ * Note that the patch might still be needed before klp_module_going()
* is called. Module functions can be called even in the GOING state
* until mod->exit() finishes. This is especially important for
* patches that modify semantic of the functions.
if (args.addr == 0)
pr_err("symbol '%s' not found in symbol table\n", name);
else if (args.count > 1 && sympos == 0) {
- pr_err("unresolvable ambiguity (%lu matches) on symbol '%s' in object '%s'\n",
- args.count, name, objname);
+ pr_err("unresolvable ambiguity for symbol '%s' in object '%s'\n",
+ name, objname);
} else if (sympos != args.count && sympos > 0) {
pr_err("symbol position %lu for symbol '%s' in object '%s' not found\n",
sympos, name, objname ? objname : "vmlinux");
return -EINVAL;
}
-/*
- * external symbols are located outside the parent object (where the parent
- * object is either vmlinux or the kmod being patched).
- */
-static int klp_find_external_symbol(struct module *pmod, const char *name,
- unsigned long *addr)
+static int klp_resolve_symbols(Elf_Shdr *relasec, struct module *pmod)
{
- const struct kernel_symbol *sym;
-
- /* first, check if it's an exported symbol */
- preempt_disable();
- sym = find_symbol(name, NULL, NULL, true, true);
- if (sym) {
- *addr = sym->value;
- preempt_enable();
- return 0;
- }
- preempt_enable();
+ int i, cnt, vmlinux, ret;
+ char objname[MODULE_NAME_LEN];
+ char symname[KSYM_NAME_LEN];
+ char *strtab = pmod->core_kallsyms.strtab;
+ Elf_Rela *relas;
+ Elf_Sym *sym;
+ unsigned long sympos, addr;
/*
- * Check if it's in another .o within the patch module. This also
- * checks that the external symbol is unique.
+ * Since the field widths for objname and symname in the sscanf()
+ * call are hard-coded and correspond to MODULE_NAME_LEN and
+ * KSYM_NAME_LEN respectively, we must make sure that MODULE_NAME_LEN
+ * and KSYM_NAME_LEN have the values we expect them to have.
+ *
+ * Because the value of MODULE_NAME_LEN can differ among architectures,
+ * we use the smallest/strictest upper bound possible (56, based on
+ * the current definition of MODULE_NAME_LEN) to prevent overflows.
*/
- return klp_find_object_symbol(pmod->name, name, 0, addr);
+ BUILD_BUG_ON(MODULE_NAME_LEN < 56 || KSYM_NAME_LEN != 128);
+
+ relas = (Elf_Rela *) relasec->sh_addr;
+ /* For each rela in this klp relocation section */
+ for (i = 0; i < relasec->sh_size / sizeof(Elf_Rela); i++) {
+ sym = pmod->core_kallsyms.symtab + ELF_R_SYM(relas[i].r_info);
+ if (sym->st_shndx != SHN_LIVEPATCH) {
+ pr_err("symbol %s is not marked as a livepatch symbol",
+ strtab + sym->st_name);
+ return -EINVAL;
+ }
+
+ /* Format: .klp.sym.objname.symname,sympos */
+ cnt = sscanf(strtab + sym->st_name,
+ ".klp.sym.%55[^.].%127[^,],%lu",
+ objname, symname, &sympos);
+ if (cnt != 3) {
+ pr_err("symbol %s has an incorrectly formatted name",
+ strtab + sym->st_name);
+ return -EINVAL;
+ }
+
+ /* klp_find_object_symbol() treats a NULL objname as vmlinux */
+ vmlinux = !strcmp(objname, "vmlinux");
+ ret = klp_find_object_symbol(vmlinux ? NULL : objname,
+ symname, sympos, &addr);
+ if (ret)
+ return ret;
+
+ sym->st_value = addr;
+ }
+
+ return 0;
}
static int klp_write_object_relocations(struct module *pmod,
struct klp_object *obj)
{
- int ret = 0;
- unsigned long val;
- struct klp_reloc *reloc;
+ int i, cnt, ret = 0;
+ const char *objname, *secname;
+ char sec_objname[MODULE_NAME_LEN];
+ Elf_Shdr *sec;
if (WARN_ON(!klp_is_object_loaded(obj)))
return -EINVAL;
- if (WARN_ON(!obj->relocs))
- return -EINVAL;
+ objname = klp_is_module(obj) ? obj->name : "vmlinux";
module_disable_ro(pmod);
+ /* For each klp relocation section */
+ for (i = 1; i < pmod->klp_info->hdr.e_shnum; i++) {
+ sec = pmod->klp_info->sechdrs + i;
+ secname = pmod->klp_info->secstrings + sec->sh_name;
+ if (!(sec->sh_flags & SHF_RELA_LIVEPATCH))
+ continue;
- for (reloc = obj->relocs; reloc->name; reloc++) {
- /* discover the address of the referenced symbol */
- if (reloc->external) {
- if (reloc->sympos > 0) {
- pr_err("non-zero sympos for external reloc symbol '%s' is not supported\n",
- reloc->name);
- ret = -EINVAL;
- goto out;
- }
- ret = klp_find_external_symbol(pmod, reloc->name, &val);
- } else
- ret = klp_find_object_symbol(obj->name,
- reloc->name,
- reloc->sympos,
- &val);
+ /*
+ * Format: .klp.rela.sec_objname.section_name
+ * See comment in klp_resolve_symbols() for an explanation
+ * of the selected field width value.
+ */
+ cnt = sscanf(secname, ".klp.rela.%55[^.]", sec_objname);
+ if (cnt != 1) {
+ pr_err("section %s has an incorrectly formatted name",
+ secname);
+ ret = -EINVAL;
+ break;
+ }
+
+ if (strcmp(objname, sec_objname))
+ continue;
+
+ ret = klp_resolve_symbols(sec, pmod);
if (ret)
- goto out;
+ break;
- ret = klp_write_module_reloc(pmod, reloc->type, reloc->loc,
- val + reloc->addend);
- if (ret) {
- pr_err("relocation failed for symbol '%s' at 0x%016lx (%d)\n",
- reloc->name, val, ret);
- goto out;
- }
+ ret = apply_relocate_add(pmod->klp_info->sechdrs,
+ pmod->core_kallsyms.strtab,
+ pmod->klp_info->symndx, i, pmod);
+ if (ret)
+ break;
}
-out:
module_enable_ro(pmod);
return ret;
}
rcu_read_unlock();
}
+ /*
+ * 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_disable_func(struct klp_func *func)
{
struct klp_ops *ops;
return;
if (list_is_singular(&ops->func_stack)) {
+ unsigned long ftrace_loc;
+
+ ftrace_loc = klp_get_ftrace_location(func->old_addr);
+ if (WARN_ON(!ftrace_loc))
+ return;
+
WARN_ON(unregister_ftrace_function(&ops->fops));
- WARN_ON(ftrace_set_filter_ip(&ops->fops, func->old_addr, 1, 0));
+ WARN_ON(ftrace_set_filter_ip(&ops->fops, ftrace_loc, 1, 0));
list_del_rcu(&func->stack_node);
list_del(&ops->node);
ops = klp_find_ops(func->old_addr);
if (!ops) {
+ unsigned long ftrace_loc;
+
+ ftrace_loc = klp_get_ftrace_location(func->old_addr);
+ if (!ftrace_loc) {
+ pr_err("failed to find location for function '%s'\n",
+ func->old_name);
+ return -EINVAL;
+ }
+
ops = kzalloc(sizeof(*ops), GFP_KERNEL);
if (!ops)
return -ENOMEM;
INIT_LIST_HEAD(&ops->func_stack);
list_add_rcu(&func->stack_node, &ops->func_stack);
- ret = ftrace_set_filter_ip(&ops->fops, func->old_addr, 0, 0);
+ ret = ftrace_set_filter_ip(&ops->fops, ftrace_loc, 0, 0);
if (ret) {
pr_err("failed to set ftrace filter for function '%s' (%d)\n",
func->old_name, ret);
if (ret) {
pr_err("failed to register ftrace handler for function '%s' (%d)\n",
func->old_name, ret);
- ftrace_set_filter_ip(&ops->fops, func->old_addr, 1, 0);
+ ftrace_set_filter_ip(&ops->fops, ftrace_loc, 1, 0);
goto err;
}
struct klp_func *func;
int ret;
- if (obj->relocs) {
- ret = klp_write_object_relocations(patch->mod, obj);
- if (ret)
- return ret;
- }
+ ret = klp_write_object_relocations(patch->mod, obj);
+ if (ret)
+ return ret;
klp_for_each_func(obj, func) {
ret = klp_find_object_symbol(obj->name, func->old_name,
{
int ret;
- if (!klp_initialized())
- return -ENODEV;
-
if (!patch || !patch->mod)
return -EINVAL;
+ if (!is_livepatch_module(patch->mod)) {
+ pr_err("module %s is not marked as a livepatch module",
+ patch->mod->name);
+ return -EINVAL;
+ }
+
+ if (!klp_initialized())
+ return -ENODEV;
+
/*
* A reference is taken on the patch module to prevent it from being
* unloaded. Right now, we don't allow patch modules to unload since
}
EXPORT_SYMBOL_GPL(klp_register_patch);
-static int klp_module_notify_coming(struct klp_patch *patch,
- struct klp_object *obj)
+int klp_module_coming(struct module *mod)
{
- struct module *pmod = patch->mod;
- struct module *mod = obj->mod;
int ret;
+ struct klp_patch *patch;
+ struct klp_object *obj;
- ret = klp_init_object_loaded(patch, obj);
- if (ret) {
- pr_warn("failed to initialize patch '%s' for module '%s' (%d)\n",
- pmod->name, mod->name, ret);
- return ret;
- }
+ if (WARN_ON(mod->state != MODULE_STATE_COMING))
+ return -EINVAL;
- if (patch->state == KLP_DISABLED)
- return 0;
+ mutex_lock(&klp_mutex);
+ /*
+ * Each module has to know that klp_module_coming()
+ * has been called. We never know what module will
+ * get patched by a new patch.
+ */
+ mod->klp_alive = true;
+
+ list_for_each_entry(patch, &klp_patches, list) {
+ klp_for_each_object(patch, obj) {
+ if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
+ continue;
- pr_notice("applying patch '%s' to loading module '%s'\n",
- pmod->name, mod->name);
+ obj->mod = mod;
- ret = klp_enable_object(obj);
- if (ret)
- pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
- pmod->name, mod->name, ret);
- return ret;
-}
+ ret = klp_init_object_loaded(patch, obj);
+ if (ret) {
+ pr_warn("failed to initialize patch '%s' for module '%s' (%d)\n",
+ patch->mod->name, obj->mod->name, ret);
+ goto err;
+ }
-static void klp_module_notify_going(struct klp_patch *patch,
- struct klp_object *obj)
-{
- struct module *pmod = patch->mod;
- struct module *mod = obj->mod;
+ if (patch->state == KLP_DISABLED)
+ break;
- if (patch->state == KLP_DISABLED)
- goto disabled;
+ pr_notice("applying patch '%s' to loading module '%s'\n",
+ patch->mod->name, obj->mod->name);
+
+ ret = klp_enable_object(obj);
+ if (ret) {
+ pr_warn("failed to apply patch '%s' to module '%s' (%d)\n",
+ patch->mod->name, obj->mod->name, ret);
+ goto err;
+ }
+
+ break;
+ }
+ }
- pr_notice("reverting patch '%s' on unloading module '%s'\n",
- pmod->name, mod->name);
+ mutex_unlock(&klp_mutex);
- klp_disable_object(obj);
+ return 0;
-disabled:
+err:
+ /*
+ * If a patch is unsuccessfully applied, return
+ * error to the module loader.
+ */
+ pr_warn("patch '%s' failed for module '%s', refusing to load module '%s'\n",
+ patch->mod->name, obj->mod->name, obj->mod->name);
+ mod->klp_alive = false;
klp_free_object_loaded(obj);
+ mutex_unlock(&klp_mutex);
+
+ return ret;
}
-static int klp_module_notify(struct notifier_block *nb, unsigned long action,
- void *data)
+void klp_module_going(struct module *mod)
{
- int ret;
- struct module *mod = data;
struct klp_patch *patch;
struct klp_object *obj;
- if (action != MODULE_STATE_COMING && action != MODULE_STATE_GOING)
- return 0;
+ if (WARN_ON(mod->state != MODULE_STATE_GOING &&
+ mod->state != MODULE_STATE_COMING))
+ return;
mutex_lock(&klp_mutex);
-
/*
- * Each module has to know that the notifier has been called.
- * We never know what module will get patched by a new patch.
+ * Each module has to know that klp_module_going()
+ * has been called. We never know what module will
+ * get patched by a new patch.
*/
- if (action == MODULE_STATE_COMING)
- mod->klp_alive = true;
- else /* MODULE_STATE_GOING */
- mod->klp_alive = false;
+ mod->klp_alive = false;
list_for_each_entry(patch, &klp_patches, list) {
klp_for_each_object(patch, obj) {
if (!klp_is_module(obj) || strcmp(obj->name, mod->name))
continue;
- if (action == MODULE_STATE_COMING) {
- obj->mod = mod;
- ret = klp_module_notify_coming(patch, obj);
- if (ret) {
- obj->mod = NULL;
- pr_warn("patch '%s' is in an inconsistent state!\n",
- patch->mod->name);
- }
- } else /* MODULE_STATE_GOING */
- klp_module_notify_going(patch, obj);
+ if (patch->state != KLP_DISABLED) {
+ pr_notice("reverting patch '%s' on unloading module '%s'\n",
+ patch->mod->name, obj->mod->name);
+ klp_disable_object(obj);
+ }
+ klp_free_object_loaded(obj);
break;
}
}
mutex_unlock(&klp_mutex);
-
- return 0;
}
-static struct notifier_block klp_module_nb = {
- .notifier_call = klp_module_notify,
- .priority = INT_MIN+1, /* called late but before ftrace notifier */
-};
-
static int __init klp_init(void)
{
int ret;
return -EINVAL;
}
- ret = register_module_notifier(&klp_module_nb);
- if (ret)
- return ret;
-
klp_root_kobj = kobject_create_and_add("livepatch", kernel_kobj);
- if (!klp_root_kobj) {
- ret = -ENOMEM;
- goto unregister;
- }
+ if (!klp_root_kobj)
+ return -ENOMEM;
return 0;
-
-unregister:
- unregister_module_notifier(&klp_module_nb);
- return ret;
}
module_init(klp_init);
return 0;
}
- static unsigned long ftrace_location_range(unsigned long start, unsigned long end)
+ /**
+ * ftrace_location_range - return the first address of a traced location
+ * if it touches the given ip range
+ * @start: start of range to search.
+ * @end: end of range to search (inclusive). @end points to the last byte
+ * to check.
+ *
+ * Returns rec->ip if the related ftrace location is a least partly within
+ * the given address range. That is, the first address of 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.
+ */
+ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
{
struct ftrace_page *pg;
struct dyn_ftrace *rec;
mutex_unlock(&ftrace_lock);
}
-static void ftrace_module_enable(struct module *mod)
+void ftrace_module_enable(struct module *mod)
{
struct dyn_ftrace *rec;
struct ftrace_page *pg;
ftrace_process_locs(mod, mod->ftrace_callsites,
mod->ftrace_callsites + mod->num_ftrace_callsites);
}
-
-static int ftrace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- struct module *mod = data;
-
- switch (val) {
- case MODULE_STATE_COMING:
- ftrace_module_enable(mod);
- break;
- case MODULE_STATE_GOING:
- ftrace_release_mod(mod);
- break;
- default:
- break;
- }
-
- return 0;
-}
-#else
-static int ftrace_module_notify(struct notifier_block *self,
- unsigned long val, void *data)
-{
- return 0;
-}
#endif /* CONFIG_MODULES */
-struct notifier_block ftrace_module_nb = {
- .notifier_call = ftrace_module_notify,
- .priority = INT_MIN, /* Run after anything that can remove kprobes */
-};
-
void __init ftrace_init(void)
{
extern unsigned long __start_mcount_loc[];
__start_mcount_loc,
__stop_mcount_loc);
- ret = register_module_notifier(&ftrace_module_nb);
- if (ret)
- pr_warning("Failed to register trace ftrace module exit notifier\n");
-
set_ftrace_early_filters();
return;
projects / mirror_ubuntu-artful-kernel.git / commitdiff