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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel…
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…/git/jikos/livepatching

Pull livepatching updates from Jiri Kosina:

 - RO/NX attribute fixes for patch module relocations from Josh
   Poimboeuf.  As part of this effort, module.c has been cleaned up as
   well and livepatching is piggy-backing on this cleanup.  Rusty is OK
   with this whole lot going through livepatching tree.

 - symbol disambiguation support from Chris J Arges.  That series is
   also

        Reviewed-by: Miroslav Benes <mbenes@suse.cz>

   but this came in only after I've alredy pushed out.  Didn't want to
   rebase because of that, hence I am mentioning it here.

 - symbol lookup fix from Miroslav Benes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Cleanup module page permission changes
  module: keep percpu symbols in module's symtab
  module: clean up RO/NX handling.
  module: use a structure to encapsulate layout.
  gcov: use within_module() helper.
  module: Use the same logic for setting and unsetting RO/NX
  livepatch: function,sympos scheme in livepatch sysfs directory
  livepatch: add sympos as disambiguator field to klp_reloc
  livepatch: add old_sympos as disambiguator field to klp_func
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torvalds committed Jan 15, 2016
2 parents c2848f2 + b56b36e commit 0f0836b
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Showing 18 changed files with 340 additions and 427 deletions.
6 changes: 5 additions & 1 deletion Documentation/ABI/testing/sysfs-kernel-livepatch
Original file line number Diff line number Diff line change
Expand Up @@ -33,12 +33,16 @@ Description:
The object directory contains subdirectories for each function
that is patched within the object.

What: /sys/kernel/livepatch/<patch>/<object>/<function>
What: /sys/kernel/livepatch/<patch>/<object>/<function,sympos>
Date: Nov 2014
KernelVersion: 3.19.0
Contact: live-patching@vger.kernel.org
Description:
The function directory contains attributes regarding the
properties and state of the patched function.

The directory name contains the patched function name and a
sympos number corresponding to the nth occurrence of the symbol
name in kallsyms for the patched object.

There are currently no such attributes.
2 changes: 1 addition & 1 deletion arch/alpha/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -160,7 +160,7 @@ apply_relocate_add(Elf64_Shdr *sechdrs, const char *strtab,

/* The small sections were sorted to the end of the segment.
The following should definitely cover them. */
gp = (u64)me->module_core + me->core_size - 0x8000;
gp = (u64)me->core_layout.base + me->core_layout.size - 0x8000;
got = sechdrs[me->arch.gotsecindex].sh_addr;

for (i = 0; i < n; i++) {
Expand Down
4 changes: 2 additions & 2 deletions arch/arc/kernel/unwind.c
Original file line number Diff line number Diff line change
Expand Up @@ -385,8 +385,8 @@ void *unwind_add_table(struct module *module, const void *table_start,
return NULL;

init_unwind_table(table, module->name,
module->module_core, module->core_size,
module->module_init, module->init_size,
module->core_layout.base, module->core_layout.size,
module->init_layout.base, module->init_layout.size,
table_start, table_size,
NULL, 0);

Expand Down
2 changes: 1 addition & 1 deletion arch/arm/kernel/module-plts.c
Original file line number Diff line number Diff line change
Expand Up @@ -32,7 +32,7 @@ struct plt_entries {

static bool in_init(const struct module *mod, u32 addr)
{
return addr - (u32)mod->module_init < mod->init_size;
return addr - (u32)mod->init_layout.base < mod->init_layout.size;
}

u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val)
Expand Down
12 changes: 6 additions & 6 deletions arch/avr32/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -118,9 +118,9 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
* Increase core size to make room for GOT and set start
* offset for GOT.
*/
module->core_size = ALIGN(module->core_size, 4);
module->arch.got_offset = module->core_size;
module->core_size += module->arch.got_size;
module->core_layout.size = ALIGN(module->core_layout.size, 4);
module->arch.got_offset = module->core_layout.size;
module->core_layout.size += module->arch.got_size;

return 0;

Expand Down Expand Up @@ -177,7 +177,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
if (!info->got_initialized) {
Elf32_Addr *gotent;

gotent = (module->module_core
gotent = (module->core_layout.base
+ module->arch.got_offset
+ info->got_offset);
*gotent = relocation;
Expand Down Expand Up @@ -255,8 +255,8 @@ int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
*/
pr_debug("GOTPC: PC=0x%x, got_offset=0x%lx, core=0x%p\n",
relocation, module->arch.got_offset,
module->module_core);
relocation -= ((unsigned long)module->module_core
module->core_layout.base);
relocation -= ((unsigned long)module->core_layout.base
+ module->arch.got_offset);
*location = relocation;
break;
Expand Down
14 changes: 7 additions & 7 deletions arch/ia64/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -486,13 +486,13 @@ module_frob_arch_sections (Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings,
static inline int
in_init (const struct module *mod, uint64_t addr)
{
return addr - (uint64_t) mod->module_init < mod->init_size;
return addr - (uint64_t) mod->init_layout.base < mod->init_layout.size;
}

static inline int
in_core (const struct module *mod, uint64_t addr)
{
return addr - (uint64_t) mod->module_core < mod->core_size;
return addr - (uint64_t) mod->core_layout.base < mod->core_layout.size;
}

static inline int
Expand Down Expand Up @@ -675,7 +675,7 @@ do_reloc (struct module *mod, uint8_t r_type, Elf64_Sym *sym, uint64_t addend,
break;

case RV_BDREL:
val -= (uint64_t) (in_init(mod, val) ? mod->module_init : mod->module_core);
val -= (uint64_t) (in_init(mod, val) ? mod->init_layout.base : mod->core_layout.base);
break;

case RV_LTV:
Expand Down Expand Up @@ -810,15 +810,15 @@ apply_relocate_add (Elf64_Shdr *sechdrs, const char *strtab, unsigned int symind
* addresses have been selected...
*/
uint64_t gp;
if (mod->core_size > MAX_LTOFF)
if (mod->core_layout.size > MAX_LTOFF)
/*
* This takes advantage of fact that SHF_ARCH_SMALL gets allocated
* at the end of the module.
*/
gp = mod->core_size - MAX_LTOFF / 2;
gp = mod->core_layout.size - MAX_LTOFF / 2;
else
gp = mod->core_size / 2;
gp = (uint64_t) mod->module_core + ((gp + 7) & -8);
gp = mod->core_layout.size / 2;
gp = (uint64_t) mod->core_layout.base + ((gp + 7) & -8);
mod->arch.gp = gp;
DEBUGP("%s: placing gp at 0x%lx\n", __func__, gp);
}
Expand Down
4 changes: 2 additions & 2 deletions arch/metag/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -176,8 +176,8 @@ static uint32_t do_plt_call(void *location, Elf32_Addr val,
tramp[1] = 0xac000001 | ((val & 0x0000ffff) << 3);

/* Init, or core PLT? */
if (location >= mod->module_core
&& location < mod->module_core + mod->core_size)
if (location >= mod->core_layout.base
&& location < mod->core_layout.base + mod->core_layout.size)
entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
else
entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
Expand Down
6 changes: 3 additions & 3 deletions arch/mips/kernel/vpe.c
Original file line number Diff line number Diff line change
Expand Up @@ -205,11 +205,11 @@ static void layout_sections(struct module *mod, const Elf_Ehdr *hdr,
|| s->sh_entsize != ~0UL)
continue;
s->sh_entsize =
get_offset((unsigned long *)&mod->core_size, s);
get_offset((unsigned long *)&mod->core_layout.size, s);
}

if (m == 0)
mod->core_text_size = mod->core_size;
mod->core_layout.text_size = mod->core_layout.size;

}
}
Expand Down Expand Up @@ -641,7 +641,7 @@ static int vpe_elfload(struct vpe *v)
layout_sections(&mod, hdr, sechdrs, secstrings);
}

v->load_addr = alloc_progmem(mod.core_size);
v->load_addr = alloc_progmem(mod.core_layout.size);
if (!v->load_addr)
return -ENOMEM;

Expand Down
32 changes: 16 additions & 16 deletions arch/parisc/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -42,9 +42,9 @@
* We are not doing SEGREL32 handling correctly. According to the ABI, we
* should do a value offset, like this:
* if (in_init(me, (void *)val))
* val -= (uint32_t)me->module_init;
* val -= (uint32_t)me->init_layout.base;
* else
* val -= (uint32_t)me->module_core;
* val -= (uint32_t)me->core_layout.base;
* However, SEGREL32 is used only for PARISC unwind entries, and we want
* those entries to have an absolute address, and not just an offset.
*
Expand Down Expand Up @@ -100,14 +100,14 @@
* or init pieces the location is */
static inline int in_init(struct module *me, void *loc)
{
return (loc >= me->module_init &&
loc <= (me->module_init + me->init_size));
return (loc >= me->init_layout.base &&
loc <= (me->init_layout.base + me->init_layout.size));
}

static inline int in_core(struct module *me, void *loc)
{
return (loc >= me->module_core &&
loc <= (me->module_core + me->core_size));
return (loc >= me->core_layout.base &&
loc <= (me->core_layout.base + me->core_layout.size));
}

static inline int in_local(struct module *me, void *loc)
Expand Down Expand Up @@ -367,13 +367,13 @@ int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
}

/* align things a bit */
me->core_size = ALIGN(me->core_size, 16);
me->arch.got_offset = me->core_size;
me->core_size += gots * sizeof(struct got_entry);
me->core_layout.size = ALIGN(me->core_layout.size, 16);
me->arch.got_offset = me->core_layout.size;
me->core_layout.size += gots * sizeof(struct got_entry);

me->core_size = ALIGN(me->core_size, 16);
me->arch.fdesc_offset = me->core_size;
me->core_size += fdescs * sizeof(Elf_Fdesc);
me->core_layout.size = ALIGN(me->core_layout.size, 16);
me->arch.fdesc_offset = me->core_layout.size;
me->core_layout.size += fdescs * sizeof(Elf_Fdesc);

me->arch.got_max = gots;
me->arch.fdesc_max = fdescs;
Expand All @@ -391,7 +391,7 @@ static Elf64_Word get_got(struct module *me, unsigned long value, long addend)

BUG_ON(value == 0);

got = me->module_core + me->arch.got_offset;
got = me->core_layout.base + me->arch.got_offset;
for (i = 0; got[i].addr; i++)
if (got[i].addr == value)
goto out;
Expand All @@ -409,7 +409,7 @@ static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
#ifdef CONFIG_64BIT
static Elf_Addr get_fdesc(struct module *me, unsigned long value)
{
Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset;
Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset;

if (!value) {
printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
Expand All @@ -427,7 +427,7 @@ static Elf_Addr get_fdesc(struct module *me, unsigned long value)

/* Create new one */
fdesc->addr = value;
fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset;
fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
return (Elf_Addr)fdesc;
}
#endif /* CONFIG_64BIT */
Expand Down Expand Up @@ -839,7 +839,7 @@ register_unwind_table(struct module *me,

table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
end = table + sechdrs[me->arch.unwind_section].sh_size;
gp = (Elf_Addr)me->module_core + me->arch.got_offset;
gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;

DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
me->arch.unwind_section, table, end, gp);
Expand Down
6 changes: 3 additions & 3 deletions arch/powerpc/kernel/module_32.c
Original file line number Diff line number Diff line change
Expand Up @@ -188,8 +188,8 @@ static uint32_t do_plt_call(void *location,

pr_debug("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location);
/* Init, or core PLT? */
if (location >= mod->module_core
&& location < mod->module_core + mod->core_size)
if (location >= mod->core_layout.base
&& location < mod->core_layout.base + mod->core_layout.size)
entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
else
entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
Expand Down Expand Up @@ -296,7 +296,7 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
}
#ifdef CONFIG_DYNAMIC_FTRACE
module->arch.tramp =
do_plt_call(module->module_core,
do_plt_call(module->core_layout.base,
(unsigned long)ftrace_caller,
sechdrs, module);
#endif
Expand Down
22 changes: 11 additions & 11 deletions arch/s390/kernel/module.c
Original file line number Diff line number Diff line change
Expand Up @@ -159,11 +159,11 @@ int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,

/* Increase core size by size of got & plt and set start
offsets for got and plt. */
me->core_size = ALIGN(me->core_size, 4);
me->arch.got_offset = me->core_size;
me->core_size += me->arch.got_size;
me->arch.plt_offset = me->core_size;
me->core_size += me->arch.plt_size;
me->core_layout.size = ALIGN(me->core_layout.size, 4);
me->arch.got_offset = me->core_layout.size;
me->core_layout.size += me->arch.got_size;
me->arch.plt_offset = me->core_layout.size;
me->core_layout.size += me->arch.plt_size;
return 0;
}

Expand Down Expand Up @@ -279,7 +279,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
if (info->got_initialized == 0) {
Elf_Addr *gotent;

gotent = me->module_core + me->arch.got_offset +
gotent = me->core_layout.base + me->arch.got_offset +
info->got_offset;
*gotent = val;
info->got_initialized = 1;
Expand All @@ -302,7 +302,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
rc = apply_rela_bits(loc, val, 0, 64, 0);
else if (r_type == R_390_GOTENT ||
r_type == R_390_GOTPLTENT) {
val += (Elf_Addr) me->module_core - loc;
val += (Elf_Addr) me->core_layout.base - loc;
rc = apply_rela_bits(loc, val, 1, 32, 1);
}
break;
Expand All @@ -315,7 +315,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_PLTOFF64: /* 16 bit offset from GOT to PLT. */
if (info->plt_initialized == 0) {
unsigned int *ip;
ip = me->module_core + me->arch.plt_offset +
ip = me->core_layout.base + me->arch.plt_offset +
info->plt_offset;
ip[0] = 0x0d10e310; /* basr 1,0; lg 1,10(1); br 1 */
ip[1] = 0x100a0004;
Expand All @@ -334,7 +334,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
val - loc + 0xffffUL < 0x1ffffeUL) ||
(r_type == R_390_PLT32DBL &&
val - loc + 0xffffffffULL < 0x1fffffffeULL)))
val = (Elf_Addr) me->module_core +
val = (Elf_Addr) me->core_layout.base +
me->arch.plt_offset +
info->plt_offset;
val += rela->r_addend - loc;
Expand All @@ -356,7 +356,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
case R_390_GOTOFF32: /* 32 bit offset to GOT. */
case R_390_GOTOFF64: /* 64 bit offset to GOT. */
val = val + rela->r_addend -
((Elf_Addr) me->module_core + me->arch.got_offset);
((Elf_Addr) me->core_layout.base + me->arch.got_offset);
if (r_type == R_390_GOTOFF16)
rc = apply_rela_bits(loc, val, 0, 16, 0);
else if (r_type == R_390_GOTOFF32)
Expand All @@ -366,7 +366,7 @@ static int apply_rela(Elf_Rela *rela, Elf_Addr base, Elf_Sym *symtab,
break;
case R_390_GOTPC: /* 32 bit PC relative offset to GOT. */
case R_390_GOTPCDBL: /* 32 bit PC rel. off. to GOT shifted by 1. */
val = (Elf_Addr) me->module_core + me->arch.got_offset +
val = (Elf_Addr) me->core_layout.base + me->arch.got_offset +
rela->r_addend - loc;
if (r_type == R_390_GOTPC)
rc = apply_rela_bits(loc, val, 1, 32, 0);
Expand Down
29 changes: 4 additions & 25 deletions arch/x86/kernel/livepatch.c
Original file line number Diff line number Diff line change
Expand Up @@ -20,8 +20,6 @@

#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/page_types.h>
#include <asm/elf.h>
#include <asm/livepatch.h>

Expand All @@ -38,11 +36,10 @@
int klp_write_module_reloc(struct module *mod, unsigned long type,
unsigned long loc, unsigned long value)
{
int ret, numpages, size = 4;
bool readonly;
size_t size = 4;
unsigned long val;
unsigned long core = (unsigned long)mod->module_core;
unsigned long core_size = mod->core_size;
unsigned long core = (unsigned long)mod->core_layout.base;
unsigned long core_size = mod->core_layout.size;

switch (type) {
case R_X86_64_NONE:
Expand All @@ -69,23 +66,5 @@ int klp_write_module_reloc(struct module *mod, unsigned long type,
/* loc does not point to any symbol inside the module */
return -EINVAL;

readonly = false;

#ifdef CONFIG_DEBUG_SET_MODULE_RONX
if (loc < core + mod->core_ro_size)
readonly = true;
#endif

/* determine if the relocation spans a page boundary */
numpages = ((loc & PAGE_MASK) == ((loc + size) & PAGE_MASK)) ? 1 : 2;

if (readonly)
set_memory_rw(loc & PAGE_MASK, numpages);

ret = probe_kernel_write((void *)loc, &val, size);

if (readonly)
set_memory_ro(loc & PAGE_MASK, numpages);

return ret;
return probe_kernel_write((void *)loc, &val, size);
}
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