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authorSergey Senozhatsky <sergey.senozhatsky@gmail.com>2017-11-10 08:48:27 +0900
committerPetr Mladek <pmladek@suse.com>2018-01-09 10:45:37 +0100
commit5633e85b2c3133051d8201b586ba195f1733096b (patch)
tree621b75567ea1ce41250785507adb4e734a4ebbf6 /arch
parent8e30788816d4d4a991136cfe9ba8715d62f31d80 (diff)
download96b-common-5633e85b2c3133051d8201b586ba195f1733096b.tar.gz
powerpc64: Add .opd based function descriptor dereference
We are moving towards separate kernel and module function descriptor dereference callbacks. This patch enables it for powerpc64. For pointers that belong to the kernel - Added __start_opd and __end_opd pointers, to track the kernel .opd section address range; - Added dereference_kernel_function_descriptor(). Now we will dereference only function pointers that are within [__start_opd, __end_opd); For pointers that belong to a module - Added dereference_module_function_descriptor() to handle module function descriptor dereference. Now we will dereference only pointers that are within [module->opd.start, module->opd.end). Link: http://lkml.kernel.org/r/20171109234830.5067-4-sergey.senozhatsky@gmail.com To: Tony Luck <tony.luck@intel.com> To: Fenghua Yu <fenghua.yu@intel.com> To: Helge Deller <deller@gmx.de> To: Benjamin Herrenschmidt <benh@kernel.crashing.org> To: Paul Mackerras <paulus@samba.org> To: Michael Ellerman <mpe@ellerman.id.au> To: James Bottomley <jejb@parisc-linux.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/module.h3
-rw-r--r--arch/powerpc/include/asm/sections.h12
-rw-r--r--arch/powerpc/kernel/module_64.c14
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S2
4 files changed, 31 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index 6c0132c7212f..7e28442827f1 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -45,6 +45,9 @@ struct mod_arch_specific {
unsigned long tramp;
#endif
+ /* For module function descriptor dereference */
+ unsigned long start_opd;
+ unsigned long end_opd;
#else /* powerpc64 */
/* Indices of PLT sections within module. */
unsigned int core_plt_section;
diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h
index 82bec63bbd4f..e335a8f846af 100644
--- a/arch/powerpc/include/asm/sections.h
+++ b/arch/powerpc/include/asm/sections.h
@@ -66,6 +66,9 @@ static inline int overlaps_kvm_tmp(unsigned long start, unsigned long end)
}
#ifdef PPC64_ELF_ABI_v1
+
+#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
+
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{
@@ -76,6 +79,15 @@ static inline void *dereference_function_descriptor(void *ptr)
ptr = p;
return ptr;
}
+
+#undef dereference_kernel_function_descriptor
+static inline void *dereference_kernel_function_descriptor(void *ptr)
+{
+ if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
#endif /* PPC64_ELF_ABI_v1 */
#endif
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 759104b99f9f..218971ac7e04 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -93,6 +93,15 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym)
{
return 0;
}
+
+void *dereference_module_function_descriptor(struct module *mod, void *ptr)
+{
+ if (ptr < (void *)mod->arch.start_opd ||
+ ptr >= (void *)mod->arch.end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
#endif
#define STUB_MAGIC 0x73747562 /* stub */
@@ -344,6 +353,11 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
sechdrs[i].sh_size);
+ else if (!strcmp(secstrings + sechdrs[i].sh_name, ".opd")) {
+ me->arch.start_opd = sechdrs[i].sh_addr;
+ me->arch.end_opd = sechdrs[i].sh_addr +
+ sechdrs[i].sh_size;
+ }
/* We don't handle .init for the moment: rename to _init */
while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init")))
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 0494e1566ee2..5dac5ab22fa2 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -278,7 +278,9 @@ SECTIONS
}
.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
+ __start_opd = .;
*(.opd)
+ __end_opd = .;
}
. = ALIGN(256);