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Diffstat (limited to 'arch/powerpc/kernel/module_32.c')
-rw-r--r--arch/powerpc/kernel/module_32.c130
1 files changed, 81 insertions, 49 deletions
diff --git a/arch/powerpc/kernel/module_32.c b/arch/powerpc/kernel/module_32.c
index d7134c614c16..f930e3395a7f 100644
--- a/arch/powerpc/kernel/module_32.c
+++ b/arch/powerpc/kernel/module_32.c
@@ -18,6 +18,7 @@
#include <linux/bug.h>
#include <linux/sort.h>
#include <asm/setup.h>
+#include <asm/text-patching.h>
/* Count how many different relocations (different symbol, different
addend) */
@@ -67,21 +68,6 @@ static int relacmp(const void *_x, const void *_y)
return 0;
}
-static void relaswap(void *_x, void *_y, int size)
-{
- uint32_t *x, *y, tmp;
- int i;
-
- y = (uint32_t *)_x;
- x = (uint32_t *)_y;
-
- for (i = 0; i < sizeof(Elf32_Rela) / sizeof(uint32_t); i++) {
- tmp = x[i];
- x[i] = y[i];
- y[i] = tmp;
- }
-}
-
/* Get the potential trampolines size required of the init and
non-init sections */
static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
@@ -113,12 +99,12 @@ static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
/* Sort the relocation information based on a symbol and
* addend key. This is a stable O(n*log n) complexity
- * alogrithm but it will reduce the complexity of
+ * algorithm but it will reduce the complexity of
* count_relocs() to linear complexity O(n)
*/
sort((void *)hdr + sechdrs[i].sh_offset,
sechdrs[i].sh_size / sizeof(Elf32_Rela),
- sizeof(Elf32_Rela), relacmp, relaswap);
+ sizeof(Elf32_Rela), relacmp, NULL);
ret += count_relocs((void *)hdr
+ sechdrs[i].sh_offset,
@@ -160,10 +146,9 @@ int module_frob_arch_sections(Elf32_Ehdr *hdr,
static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val)
{
- if (entry->jump[0] != (PPC_INST_ADDIS | __PPC_RT(R12) | PPC_HA(val)))
+ if (entry->jump[0] != PPC_RAW_LIS(_R12, PPC_HA(val)))
return 0;
- if (entry->jump[1] != (PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12) |
- PPC_LO(val)))
+ if (entry->jump[1] != PPC_RAW_ADDI(_R12, _R12, PPC_LO(val)))
return 0;
return 1;
}
@@ -178,8 +163,7 @@ 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->core_layout.base
- && location < mod->core_layout.base + mod->core_layout.size)
+ if (within_module_core((unsigned long)location, mod))
entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
else
entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
@@ -190,21 +174,25 @@ static uint32_t do_plt_call(void *location,
entry++;
}
- /*
- * lis r12, sym@ha
- * addi r12, r12, sym@l
- * mtctr r12
- * bctr
- */
- entry->jump[0] = PPC_INST_ADDIS | __PPC_RT(R12) | PPC_HA(val);
- entry->jump[1] = PPC_INST_ADDI | __PPC_RT(R12) | __PPC_RA(R12) | PPC_LO(val);
- entry->jump[2] = PPC_INST_MTCTR | __PPC_RS(R12);
- entry->jump[3] = PPC_INST_BCTR;
+ if (patch_instruction(&entry->jump[0], ppc_inst(PPC_RAW_LIS(_R12, PPC_HA(val)))))
+ return 0;
+ if (patch_instruction(&entry->jump[1], ppc_inst(PPC_RAW_ADDI(_R12, _R12, PPC_LO(val)))))
+ return 0;
+ if (patch_instruction(&entry->jump[2], ppc_inst(PPC_RAW_MTCTR(_R12))))
+ return 0;
+ if (patch_instruction(&entry->jump[3], ppc_inst(PPC_RAW_BCTR())))
+ return 0;
pr_debug("Initialized plt for 0x%x at %p\n", val, entry);
return (uint32_t)entry;
}
+static int patch_location_16(uint32_t *loc, u16 value)
+{
+ loc = PTR_ALIGN_DOWN(loc, sizeof(u32));
+ return patch_instruction(loc, ppc_inst((*loc & 0xffff0000) | value));
+}
+
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex,
@@ -238,44 +226,46 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
case R_PPC_ADDR16_LO:
/* Low half of the symbol */
- *(uint16_t *)location = value;
+ if (patch_location_16(location, PPC_LO(value)))
+ return -EFAULT;
break;
case R_PPC_ADDR16_HI:
/* Higher half of the symbol */
- *(uint16_t *)location = (value >> 16);
+ if (patch_location_16(location, PPC_HI(value)))
+ return -EFAULT;
break;
case R_PPC_ADDR16_HA:
- /* Sign-adjusted lower 16 bits: PPC ELF ABI says:
- (((x >> 16) + ((x & 0x8000) ? 1 : 0))) & 0xFFFF.
- This is the same, only sane.
- */
- *(uint16_t *)location = (value + 0x8000) >> 16;
+ if (patch_location_16(location, PPC_HA(value)))
+ return -EFAULT;
break;
case R_PPC_REL24:
if ((int)(value - (uint32_t)location) < -0x02000000
- || (int)(value - (uint32_t)location) >= 0x02000000)
+ || (int)(value - (uint32_t)location) >= 0x02000000) {
value = do_plt_call(location, value,
sechdrs, module);
+ if (!value)
+ return -EFAULT;
+ }
/* Only replace bits 2 through 26 */
pr_debug("REL24 value = %08X. location = %08X\n",
value, (uint32_t)location);
pr_debug("Location before: %08X.\n",
*(uint32_t *)location);
- *(uint32_t *)location
- = (*(uint32_t *)location & ~0x03fffffc)
- | ((value - (uint32_t)location)
- & 0x03fffffc);
+ value = (*(uint32_t *)location & ~PPC_LI_MASK) |
+ PPC_LI(value - (uint32_t)location);
+
+ if (patch_instruction(location, ppc_inst(value)))
+ return -EFAULT;
+
pr_debug("Location after: %08X.\n",
*(uint32_t *)location);
pr_debug("ie. jump to %08X+%08X = %08X\n",
- *(uint32_t *)location & 0x03fffffc,
- (uint32_t)location,
- (*(uint32_t *)location & 0x03fffffc)
- + (uint32_t)location);
+ *(uint32_t *)PPC_LI((uint32_t)location), (uint32_t)location,
+ (*(uint32_t *)PPC_LI((uint32_t)location)) + (uint32_t)location);
break;
case R_PPC_REL32:
@@ -295,14 +285,56 @@ int apply_relocate_add(Elf32_Shdr *sechdrs,
}
#ifdef CONFIG_DYNAMIC_FTRACE
+notrace int module_trampoline_target(struct module *mod, unsigned long addr,
+ unsigned long *target)
+{
+ ppc_inst_t jmp[4];
+
+ /* Find where the trampoline jumps to */
+ if (copy_inst_from_kernel_nofault(jmp, (void *)addr))
+ return -EFAULT;
+ if (__copy_inst_from_kernel_nofault(jmp + 1, (void *)addr + 4))
+ return -EFAULT;
+ if (__copy_inst_from_kernel_nofault(jmp + 2, (void *)addr + 8))
+ return -EFAULT;
+ if (__copy_inst_from_kernel_nofault(jmp + 3, (void *)addr + 12))
+ return -EFAULT;
+
+ /* verify that this is what we expect it to be */
+ if ((ppc_inst_val(jmp[0]) & 0xffff0000) != PPC_RAW_LIS(_R12, 0))
+ return -EINVAL;
+ if ((ppc_inst_val(jmp[1]) & 0xffff0000) != PPC_RAW_ADDI(_R12, _R12, 0))
+ return -EINVAL;
+ if (ppc_inst_val(jmp[2]) != PPC_RAW_MTCTR(_R12))
+ return -EINVAL;
+ if (ppc_inst_val(jmp[3]) != PPC_RAW_BCTR())
+ return -EINVAL;
+
+ addr = (ppc_inst_val(jmp[1]) & 0xffff) | ((ppc_inst_val(jmp[0]) & 0xffff) << 16);
+ if (addr & 0x8000)
+ addr -= 0x10000;
+
+ *target = addr;
+
+ return 0;
+}
+
int module_finalize_ftrace(struct module *module, const Elf_Shdr *sechdrs)
{
- module->arch.tramp = do_plt_call(module->core_layout.base,
+ module->arch.tramp = do_plt_call(module->mem[MOD_TEXT].base,
(unsigned long)ftrace_caller,
sechdrs, module);
if (!module->arch.tramp)
return -ENOENT;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ module->arch.tramp_regs = do_plt_call(module->mem[MOD_TEXT].base,
+ (unsigned long)ftrace_regs_caller,
+ sechdrs, module);
+ if (!module->arch.tramp_regs)
+ return -ENOENT;
+#endif
+
return 0;
}
#endif
generated by cgit (git 2.34.1) at 2025-07-24 08:49:35 +0000