I built my application(c/c++) on linux and stripped it using "strip" command. I thought without giving any options it will strip all the debugging info from the original binary. I stripped using following:
strip my_app -o $odir/my_app_stripped (where $odir is preconfigured location)
However, when I do the following:
objdump -h my_app_stripped
It gives me the following output:
my_app_stripped: file format elf32-i386
Sections:
Idx Name Size VMA LMA File off Algn
0 .interp 0000002c 00048154 00048154 00000154 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
1 .note.ABI-tag 00000020 00048180 00048180 00000180 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
2 .hash 00067dcc 000481a0 000481a0 000001a0 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
3 .dynsym 0011f6e0 000aff6c 000aff6c 00067f6c 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
4 .dynstr 00488e4c 001cf64c 001cf64c 0018764c 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
5 .gnu.version 00023edc 00658498 00658498 00610498 2**1
CONTENTS, ALLOC, LOAD, READONLY, DATA
6 .gnu.version_r 00000290 0067c374 0067c374 00634374 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
7 .rel.dyn 00006860 0067c604 0067c604 00634604 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
8 .rel.plt 00003768 00682e64 00682e64 0063ae64 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
9 .init 00000017 006865cc 006865cc 0063e5cc 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
10 .plt 00006ee0 006865e4 006865e4 0063e5e4 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
11 .text 01120918 0068d4d0 0068d4d0 006454d0 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
12 BINK 00018d20 017addf0 017addf0 01765df0 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
13 BINK32 00001350 017c6b10 017c6b10 0177eb10 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
14 BINK16 00001008 017c7e60 017c7e60 0177fe60 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
15 BINKP8 000008fb 017c8e70 017c8e70 01780e70 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
16 BINKY16 000008e1 017c9770 017c9770 01781770 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
17 BINKY12 000001b0 017ca060 017ca060 01782060 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
18 .fini 0000001a 017ca210 017ca210 01782210 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
19 .rodata 00164204 017ca240 017ca240 01782240 2**6
CONTENTS, ALLOC, LOAD, READONLY, DATA
20 .debug$S 000010f8 0192e444 0192e444 018e6444 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
21 BINKCONST 00004e40 0192f540 0192f540 018e7540 2**6
CONTENTS, ALLOC, LOAD, READONLY, DATA
22 .debug$F 00000250 01934380 01934380 018ec380 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
23 .rdata 00000080 019345d0 019345d0 018ec5d0 2**4
CONTENTS, ALLOC, LOAD, READONLY, DATA
24 .eh_frame_hdr 0004765c 01934650 01934650 018ec650 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
25 .eh_frame 00128fec 0197bcac 0197bcac 01933cac 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
26 .gcc_except_table 000aaaf1 01aa4c98 01aa4c98 01a5cc98 2**2
CONTENTS, ALLOC, LOAD, READONLY, DATA
27 .tbss 00000004 01b5078c 01b5078c 01b0778c 2**2
ALLOC, THREAD_LOCAL
28 .ctors 000004f4 01b5078c 01b5078c 01b0778c 2**2
CONTENTS, ALLOC, LOAD, DATA
29 .dtors 000004d0 01b50c80 01b50c80 01b07c80 2**2
CONTENTS, ALLOC, LOAD, DATA
30 .jcr 00000004 01b51150 01b51150 01b08150 2**2
CONTENTS, ALLOC, LOAD, DATA
31 .data.rel.ro 00012160 01b51160 01b51160 01b08160 2**5
CONTENTS, ALLOC, LOAD, DATA
32 .dynamic 00000240 01b632c0 01b632c0 01b1a2c0 2**2
CONTENTS, ALLOC, LOAD, DATA
33 .got 00002e6c 01b63500 01b63500 01b1a500 2**2
CONTENTS, ALLOC, LOAD, DATA
34 .data 000481a8 01b66380 01b66380 01b1d380 2**5
CONTENTS, ALLOC, LOAD, DATA
35 .got.plt 00001bc0 01bae528 01bae528 01b65528 2**2
CONTENTS, ALLOC, LOAD, DATA
36 BINKDATA 00002de0 01bb0100 01bb0100 01b67100 2**5
CONTENTS, ALLOC, LOAD, DATA
37 .bss 0046f8e8 01bb2ee0 01bb2ee0 01b69ee0 2**5
ALLOC
38 BINKBSS 000067a0 020227e0 020227e0 01b69ee0 2**5
ALLOC
39 .comment 00002d95 00000000 00000000 01b69ee0 2**0
CONTENTS, READONLY
40 .drectve 0000005d 00000000 00000000 01b6cc75 2**0
CONTENTS, READONLY
So, if debugging was all removed what are the sections ".debug$S" and ".debug$F" ?
Despite their names those sections aren't debugging sections, at least not according to their flags. You'll notice that they have the same flags, CONTENTS, ALLOC, LOAD, READONLY, DATA, as a number of other sections in the executable like .rodata. These flags say that the section is meant to be loaded into memory and used as data. The strip command has no way knowing if these sections are unnecessary or not. Discarding the .rodata section would break your program, causing it to crash every time its run. The strip command doesn't know that discarding the .debug$F and .debug$S sections wouldn't do the same thing.
Note that you don't normally find sections named .debug$F and debug$S in ELF executables. The DWARF debugging information normally used in ELF files is stored in sections whose names begin with .debug_ not .debug$. They also have the DEBUGGING flag set (but not the LOAD flag) so strip knows that they're debugging sections and that it should and can remove. Sections with these names are normally only seen in PECOFF files produced by Microsoft's compilers. They contain debugging information in Microsoft's proprietary format.
If you can determine that these sections don't contain useful information and want to get rid of them you should remove them from the object files before linking. Since they're loaded into memory, it's probably too late to completely remove them after linking. You can use a command like objcopy -R ".debug$*" foo.o foo-stripped.o and then link with foo-stripped.o instead of foo.o.
You might also want to strip the .comment and .directve sections from the executable, as the these sections probably aren't necessary. In particular .directve is another PECOFF section you don't normally see in ELF files.