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freebsd/lib/libelf/elf_getphnum.3
Joseph Koshy f6c0f35e07 Keep shadow copies of the e_shnum', e_phnum' and `e_shstrndx'
members of the ELF Executable Header inside the library-private
`struct _Elf' descriptor and only update the underlying Elf{32,64}_Ehdr
structure on an elf_update(3) call.  These fields of the Ehdr
structure are technically `out of bounds' for an application program
per the ELF(3) API, but we've seen applications that initialize
a new Ehdr structure using memcpy(), messing up the library's
invariants. [1]

Implement elf_getphnum() and handle ELF objects with more than
64K program header table entries.

Reported by:	jb [1]
2006-12-25 02:22:22 +00:00

88 lines
2.6 KiB
Groff

.\" Copyright (c) 2006 Joseph Koshy. All rights reserved.
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.\" $FreeBSD$
.\"
.Dd December 16, 2006
.Os
.Dt ELF_GETPHNUM 3
.Sh NAME
.Nm elf_getphnum
.Nd return the number of program headers in an ELF file
.Sh LIBRARY
.Lb libelf
.Sh SYNOPSIS
.In libelf.h
.Ft int
.Fn elf_getphnum "Elf *elf" "size_t *phnum"
.Sh DESCRIPTION
Function
.Fn elf_getphnum
retrieves the number of ELF program headers associated with descriptor
.Ar elf
and stores it into the location pointed to by argument
.Ar phnum .
.Pp
This routine allows applications to uniformly process both normal ELF
objects and ELF objects that use extended numbering.
.Pp
.Sh RETURN VALUES
Function
.Fn elf_getphnum
returns a non-zero value if successful, or zero in case of an
error.
.Sh ERRORS
Function
.Fn elf_getphnum
can fail with the following errors:
.Bl -tag -width "[ELF_E_RESOURCE]"
.It Bq Er ELF_E_ARGUMENT
A NULL value was passed in for argument
.Ar elf .
.It Bq Er ELF_E_ARGUMENT
Argument
.Ar elf
was not for an ELF file.
.It Bq Er ELF_E_ARGUMENT
Argument
.Ar elf
lacks an ELF Executable Header.
.It Bq Er ELF_E_HEADER
The ELF Executable Header associated with argument
.Ar elf
was corrupt.
.It Bq Er ELF_E_SECTION
The section header at index
.Dv SHN_UNDEF
was corrupt.
.El
.Sh SEE ALSO
.Xr elf 3 ,
.Xr elf32_getehdr 3 ,
.Xr elf64_getehdr 3 ,
.Xr elf_getident 3 ,
.Xr elf_getshnum 3 ,
.Xr elf_getshstrndx 3 ,
.Xr gelf 3 ,
.Xr gelf_getehdr 3