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author | Sergey Senozhatsky <sergey.senozhatsky@gmail.com> | 2017-11-10 08:48:27 +0900 |
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committer | Petr Mladek <pmladek@suse.com> | 2018-01-09 10:45:37 +0100 |
commit | 5633e85b2c3133051d8201b586ba195f1733096b (patch) | |
tree | 621b75567ea1ce41250785507adb4e734a4ebbf6 | |
parent | 8e30788816d4d4a991136cfe9ba8715d62f31d80 (diff) | |
download | op-kernel-dev-5633e85b2c3133051d8201b586ba195f1733096b.zip op-kernel-dev-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>
-rw-r--r-- | arch/powerpc/include/asm/module.h | 3 | ||||
-rw-r--r-- | arch/powerpc/include/asm/sections.h | 12 | ||||
-rw-r--r-- | arch/powerpc/kernel/module_64.c | 14 | ||||
-rw-r--r-- | arch/powerpc/kernel/vmlinux.lds.S | 2 |
4 files changed, 31 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h index 6c0132c..7e28442 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 82bec63..e335a8f 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 759104b..218971a 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 0494e15..5dac5ab 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); |