#include <linux/vmalloc.h>
#include <linux/ftrace.h>
#include <linux/bug.h>
+#include <linux/uaccess.h>
#include <asm/module.h>
#include <asm/firmware.h>
#include <asm/code-patching.h>
#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;
+
+static func_desc_t func_desc(unsigned long addr)
+{
+ return addr;
+}
+static unsigned long func_addr(unsigned long addr)
+{
+ return addr;
+}
+static unsigned long stub_func_addr(func_desc_t func)
+{
+ return func;
+}
+
+/* PowerPC64 specific values for the Elf64_Sym st_other field. */
+#define STO_PPC64_LOCAL_BIT 5
+#define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT)
+#define PPC64_LOCAL_ENTRY_OFFSET(other) \
+ (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
+
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+ /* sym->st_other indicates offset to local entry point
+ * (otherwise it will assume r12 is the address of the start
+ * of function and try to derive r2 from it). */
+ 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;
+
+static func_desc_t func_desc(unsigned long addr)
+{
+ return *(struct ppc64_opd_entry *)addr;
+}
+static unsigned long func_addr(unsigned long addr)
+{
+ return func_desc(addr).funcaddr;
+}
+static unsigned long stub_func_addr(func_desc_t func)
+{
+ return func.funcaddr;
+}
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+ return 0;
+}
#endif
/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
jump, actually, to reset r2 (TOC+0x8000). */
struct ppc64_stub_entry
{
- /* 28 byte jump instruction sequence (7 instructions) */
+ /* 28 byte jump instruction sequence (7 instructions). We only
+ * 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;
/* Data for the above code */
- struct ppc64_opd_entry opd;
+ func_desc_t funcdata;
};
/*
* end of the stub code, and patch the stub address (32-bits relative
* to the TOC ptr, r2) into the stub.
*/
-static struct ppc64_stub_entry ppc64_stub =
-{ .jump = {
+
+static u32 ppc64_stub_insns[] = {
0x3d620000, /* addis r11,r2, <high> */
0x396b0000, /* addi r11,r11, <low> */
/* Save current r2 value in magic place on the stack. */
0xe98b0020, /* ld r12,32(r11) */
#if !defined(_CALL_ELF) || _CALL_ELF != 2
/* Set up new r2 from function descriptor */
- 0xe84b0026, /* ld r2,40(r11) */
+ 0xe84b0028, /* ld r2,40(r11) */
#endif
0x7d8903a6, /* mtctr r12 */
0x4e800420 /* bctr */
-} };
+};
+
+#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)
+{
+ unsigned int i;
+ u32 insns[ARRAY_SIZE(ppc64_stub_insns)];
+
+ BUILD_BUG_ON(sizeof(ppc64_stub_insns) != sizeof(ppc64_stub_mask));
+
+ if (probe_kernel_read(insns, p, sizeof(insns)))
+ 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;
+
+ if (probe_kernel_read(buf, trampoline, sizeof(buf)))
+ return -EFAULT;
+
+ upper = buf[0] & 0xffff;
+ lower = buf[1] & 0xffff;
+
+ /* perform the addis/addi, both signed */
+ offset = ((short)upper << 16) + (short)lower;
+
+ /*
+ * 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(target, toc_entry, sizeof(*target)))
+ return -EFAULT;
+
+ return 0;
+}
+
+#endif
/* Count how many different 24-bit relocations (different symbol,
different addend) */
for (i = 1; i < numsyms; i++) {
if (syms[i].st_shndx == SHN_UNDEF
- && strcmp(strtab + syms[i].st_name, ".TOC.") == 0)
+ && strcmp(strtab + syms[i].st_name, "TOC.") == 0)
return &syms[i];
}
return NULL;
/* Patch stub to reference function and correct r2 value. */
static inline int create_stub(Elf64_Shdr *sechdrs,
struct ppc64_stub_entry *entry,
- struct ppc64_opd_entry *opd,
+ unsigned long addr,
struct module *me)
{
long reladdr;
- *entry = ppc64_stub;
+ memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns));
/* Stub uses address relative to r2. */
reladdr = (unsigned long)entry - my_r2(sechdrs, me);
entry->jump[0] |= PPC_HA(reladdr);
entry->jump[1] |= PPC_LO(reladdr);
- entry->opd.funcaddr = opd->funcaddr;
- entry->opd.r2 = opd->r2;
+ entry->funcdata = func_desc(addr);
return 1;
}
-/* Create stub to jump to function described in this OPD: we need the
+/* 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,
- unsigned long opdaddr,
+ unsigned long addr,
struct module *me)
{
struct ppc64_stub_entry *stubs;
- struct ppc64_opd_entry *opd = (void *)opdaddr;
unsigned int i, num_stubs;
num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs);
/* Find this stub, or if that fails, the next avail. entry */
stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr;
- for (i = 0; stubs[i].opd.funcaddr; i++) {
+ for (i = 0; stub_func_addr(stubs[i].funcdata); i++) {
BUG_ON(i >= num_stubs);
- if (stubs[i].opd.funcaddr == opd->funcaddr)
+ if (stub_func_addr(stubs[i].funcdata) == func_addr(addr))
return (unsigned long)&stubs[i];
}
- if (!create_stub(sechdrs, &stubs[i], opd, me))
+ if (!create_stub(sechdrs, &stubs[i], addr, me))
return 0;
return (unsigned long)&stubs[i];
return -ENOENT;
if (!restore_r2((u32 *)location + 1, me))
return -ENOEXEC;
- }
+ } else
+ value += local_entry_offset(sym);
/* Convert value to relative */
value -= (unsigned long)location;
projects / mirror_ubuntu-zesty-kernel.git / blobdiff