Currently, the AT_FLAGS in the elf auxiliary vector are set to 0 by default by the kernel. Some architectures might need to expose to the userspace a non-zero value to advertise some platform specific ABI functionalities.
Make AT_FLAGS configurable by the architectures that require it.
Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will.deacon@arm.com CC: Andrey Konovalov andreyknvl@google.com CC: Alexander Viro viro@zeniv.linux.org.uk Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com --- fs/binfmt_elf.c | 6 +++++- fs/binfmt_elf_fdpic.c | 6 +++++- fs/compat_binfmt_elf.c | 5 +++++ 3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 7d09d125f148..f699a9ef5112 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -84,6 +84,10 @@ static int elf_core_dump(struct coredump_params *cprm); #define ELF_CORE_EFLAGS 0 #endif
+#ifndef ELF_AT_FLAGS +#define ELF_AT_FLAGS 0 +#endif + #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) @@ -249,7 +253,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); NEW_AUX_ENT(AT_BASE, interp_load_addr); - NEW_AUX_ENT(AT_FLAGS, 0); + NEW_AUX_ENT(AT_FLAGS, ELF_AT_FLAGS); NEW_AUX_ENT(AT_ENTRY, exec->e_entry); NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index b53bb3729ac1..cf1e680a6b88 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -82,6 +82,10 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *, static int elf_fdpic_core_dump(struct coredump_params *cprm); #endif
+#ifndef ELF_AT_FLAGS +#define ELF_AT_FLAGS 0 +#endif + static struct linux_binfmt elf_fdpic_format = { .module = THIS_MODULE, .load_binary = load_elf_fdpic_binary, @@ -651,7 +655,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); - NEW_AUX_ENT(AT_FLAGS, 0); + NEW_AUX_ENT(AT_FLAGS, ELF_AT_FLAGS); NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index 15f6e96b3bd9..a21cf99701ae 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -79,6 +79,11 @@ #define ELF_HWCAP2 COMPAT_ELF_HWCAP2 #endif
+#ifdef COMPAT_ELF_AT_FLAGS +#undef ELF_AT_FLAGS +#define ELF_AT_FLAGS COMPAT_ELF_AT_FLAGS +#endif + #ifdef COMPAT_ARCH_DLINFO #undef ARCH_DLINFO #define ARCH_DLINFO COMPAT_ARCH_DLINFO