The lowest bit of the thumb instruction is 1 by default, which is used to distinguish arm instructions and thumb instructions.
Fixed the problem of misalignment of symbol table when performing binary search
In arm, the lowest bit of the instruction is 1, which is a thumb instruction, and 0, which is an arm instruction.
The nm command was used in mkallsym.sh before, and the result it will return will set the lowest bit of the thumb instruction to 0. There will be a one-byte deviation during binary search, so mkallsyms.py will also set the lowest bit to 0 according to the previous format.
```sh
arm-none-eabi-nm -Cn nuttx | grep hello
0801c384 T hello_main
arm-none-eabi-objdump nuttx -t |grep hello
0801c384 g F .text 0000004c hello_main
arm-none-eabi-readelf nuttx -s |grep hello
4558: 0801c385 76 FUNC GLOBAL DEFAULT 1 hello_main
```
However, in the following case, when you need to find the function address according to the symbol name and execute the corresponding function, the lowest address obtained is 0. It will follow the arm instruction, causing an exception.
```c
void sym_test(void)
{
printf("call sym_test\n");
}
int main(int argc, FAR char *argv[])
{
FAR void *addr = sym_test;
printf("sym_test:%p %pS\n",addr, addr);
printf("sym_test - 1: %pS\n", (char *)addr - 1);
printf("sym_test + 1: %pS\n", (char *)addr + 1);
size_t size;
void (*func)(void);
const struct symtab_s *sym = allsyms_findbyname("sym_test", &size);
printf("sym_test:%p %pS\n",sym, sym);
func = sym->sym_value;
func();
return 0;
}
```
Therefore, you need to change mkallsyms.py back to the correct result and correct the binary search.
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>
As pointed out in #11322 there is a hardware design issue in RISC-V that
affects RV64 relocations. The problem is with how address bits are loaded
into registers via lui / auipc and sign extension.
If the hi20 relocation value happens to have its 32-bit sign bit set, i.e.
value is 0x80000000 (but not negative! i.e. negative in 64-bit format) the
relocation will fail, as the address is erroneously sign extended:
0x00000000_80000000 becomes 0xffffffff_80000000 which is not correct.
Also, make sure the correct opcode is used with PCREL_HI20, it expects
AUIPC (not LUI). The C compiler will never emit such code but when hand-
writing assembly code this can happen.
There is a problem with the current elf loader for risc-v: when a pair of
PCREL_HI20 / LO12 relocations are encountered, it is assumed that these
will follow each other immediately, as follows:
label:
auipc a0, %pcrel_hi(symbol) // R_RISCV_PCREL_HI20
load/store a0, %pcrel_lo(label)(a0) // R_RISCV_PCREL_LO12_I/S
With this assumption, the hi/lo relocations are both done when a hi20
relocation entry is encountered, first to the current instruction (addr)
and to the next instruction (addr + 4).
However, this assumption is wrong. There is nothing in the elf relocation
specification[1] that mandates this. Thus, the hi/lo relocation always
needs to first fixup the hi-part, and when the lo-part is encountered, it
needs to find the corresponding hi relocation entry, via the given "label".
This necessitates (re-)visiting the relocation entries for the current
section as well as looking for "label" in the symbol table.
The NuttX elf loader does not allow such operations to be done in the
machine specific part, so this patch fixes the relocation issue by
introducing an architecture specific cache for the hi20 relocation and
symbol table entries. When a lo12 relocation is encountered, the cache
can be consulted to find the hi20 part.
[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc
we can use uart to debug nuttx,like debugger:
1. read/write memory
2. Use watchpoint,breakpoint,single step.
use up_debugpoint api
3. Ctrl+c to stop, continue, or single step.
hold uart send and receive
4. register a panic event, when crash or assert/panic, we use uart to
debug.
Signed-off-by: anjiahao <anjiahao@xiaomi.com>
Add registration function instrumentation API,
which can achieve instrumentation of entering and
exiting functions through the compiler's functionality.
We can use CONFIG_ARCH_INSTRUMENT_ALL to add instrumentation for all
source, or add '-finstrument-functions' to CFLAGS for Part of the
source.
Notice:
1. use CONFIG_ARCH_INSTRUMENT_ALL must mark _start or entry noinstrument_function,
becuase bss not set.
2. Make sure your callbacks are not instrumented recursively.
use instrument_register to register entry function and exit function.
They will be called by the instrumented function
Signed-off-by: anjiahao <anjiahao@xiaomi.com>
Binary nibble to/from ascii hex conversion was buggy on both
lib_slcdencode and lib_slcddecode libraries.
This bug caused the slcd library to fail to decode 5-byte sequence command
which have 'count' argument value bigger than 0x9.
Signed-off-by: Federico Braghiroli <federico.braghiroli@gmail.com>
Adds support for POSIX interface open_memstream() that allows writing
to dynamic memory buffer stream. The stream is dynamically reallocated
as the buffer grows with initial size set to zero.
The caller has to free the buffer after the stream is closed.
The implementation uses fopencookie() for custom stream operations and
callbacks.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
This moves all the public POSIX semaphore functions into libc and with
this most of the user-space logic is also moved; namely cancel point and
errno handling.
This also removes the need for the _SEM_XX macros used to differentiate
which API is used per user-/kernel mode. Such macros are henceforth
unnecessary.
PR #11165 causes an unnecessary regression; task_delete no longer works,
if the deleted task is from another group.
The logic that prevents this comes from:
nxnotify_cancellation() ->
tls_get_info_pid() ->
nxsched_get_stackinfo()
Which checks for permissions, which does not make sense in this case since
it is the kernel asking for the stack information.
Fix this by partially reverting 11165 and implementing a direct path for
the kernel to query for any tasks TLS.
This moves task / thread cancel point logic from the NuttX kernel into
libc, while the data needed by the cancel point logic is moved to TLS.
The change is an enabler to move user-space APIs to libc as well, for
a coherent user/kernel separation.
Add a minimal implementation to suppress warnings when building
application code shared with other operating systems.
For example:
When building with a c++ compiler and GCC 12.2.0, the following warning is emitted:
nuttx/include/spawn.h:178:40: warning: statement has no effect [-Wunused-value]
178 | #define posix_spawnattr_destroy(attr) (0)
Add support for POSIX interface fmemopen(). This interface open a memory
buffer as a stream and permits access to this buffer specified by mode.
This allows I/O operations to be performed on the memory buffer.
The implementation uses fopencookie() for custom stream operations and
callbacks.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
CPP: nuttx-names.in-> nuttx-names.dat
LD: nuttx
/usr/lib/gcc/x86_64-pc-msys/13.2.0/../../../../x86_64-pc-msys/bin/ld: nuttx.rel:/d/a/nuttx_windows/nuttx_windows/nuttxspace/nuttx/libs/libc/stdlib/lib_exit.c:48: multiple definition of `__dso_handle'; /usr/lib/gcc/x86_64-pc-msys/13.2.0/crtbegin.o:cygming-crtbeg:(.data+0x0): first defined here
CC: icmp/icmp_input.c modlib/modlib_load.c: In function 'modlib_elfsize':
modlib/modlib_load.c:87:30: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
87 | textaddr = (FAR void *)phdr->p_vaddr;
| ^
cc1: all warnings being treated as errors
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
modlib/modlib_symbols.c: In function ‘modlib_symcallback’:
modlib/modlib_symbols.c:215:13: warning: implicit declaration of function ‘modlib_depend’; did you mean ‘modlib_read’? [-Wimplicit-function-declaration]
215 | ret = modlib_depend(exportinfo->modp, modp);
| ^~~~~~~~~~~~~
| modlib_read
Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
