The cast valid since TASK_SIZE * 2 will never actually cause overflow.
| CC fs/binfmt_elf.o
| In file included from ../include/linux/elf.h:4:0,
| from ../include/linux/module.h:15,
| from ../fs/binfmt_elf.c:12:
| ../fs/binfmt_elf.c: In function load_elf_binar:
| ../arch/arc/include/asm/elf.h:57:29: warning: integer overflow in expression [-Woverflow]
| #define ELF_ET_DYN_BASE (2 * TASK_SIZE / 3)
| ^
| ../fs/binfmt_elf.c:921:16: note: in expansion of macro ELF_ET_DYN_BASE
| load_bias = ELF_ET_DYN_BASE - vaddr;
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The upstream kernel ABI (v3) is different from current out-of-tree (v2):
* no-legacy-syscalls
* user_regs_struct layout has changed
So we rev up the ABI version
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ptrace regset interface relies on ELF_NGREG for ceiling the size of user
request. So any larger request (even if legit) would be clipped.
The existing def of ELF_NGREG didn't use user_regs_struct and was
technically one placeholder short (stop_pc) - although the current code
would still work because pt_regs includes a bunch of extra fields,
making
ELF_NGREG >= sizeof(struct user_regs_struct)/sizeof(long)
But we need to remove this ambiguity, specially since pt_regs should NOT
be directly associated with with anything userspace-ish.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* L1_CACHE_SHIFT
* PAGE_SIZE, PAGE_OFFSET
* struct pt_regs, struct user_regs_struct
* struct thread_struct, cpu_relax(), task_pt_regs(), start_thread(), ...
* struct thread_info, THREAD_SIZE, INIT_THREAD_INFO(), TIF_*, ...
* BUG()
* ELF_*
* Elf_*
To disallow user-space visibility into some of the core kernel data-types
such as struct pt_regs, #ifdef __KERNEL__ which also makes the UAPI header
spit (further patch in the series) to NOT export it to asm/uapi/ptrace.h
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Vineet Gupta