| 7f854858 | 10-Jan-2023 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: make compiler and assembler agree on the section around _start
The out-of-block asm() statement carrying _start does not allow the
compiler to know what section the assembly code is be
tools/nolibc: make compiler and assembler agree on the section around _start
The out-of-block asm() statement carrying _start does not allow the
compiler to know what section the assembly code is being emitted to,
and there's no easy way to push/pop the current section and restore
it. It sometimes causes issues depending on the include files ordering
and compiler optimizations. For example if a variable is declared
immediately before the asm() block and another one after, the compiler
assumes that the current section is still .bss and doesn't re-emit it,
making the second variable appear inside the .text section instead.
Forcing .bss at the end of the _start block doesn't work either because
at certain optimizations the compiler may reorder blocks and will make
some real code appear just after this block.
A significant number of solutions were attempted, but many of them were
still sensitive to section reordering. In the end, the best way to make
sure the compiler and assembler agree on the current section is to place
this code inside a function. Here the function is directly called _start
and configured not to emit a frame-pointer, hence to have no prologue.
If some future architectures would still emit some prologue, another
working approach consists in naming the function differently and placing
the _start label inside the asm statement. But the current solution is
simpler.
It was tested with nolibc-test at -O,-O0,-O2,-O3,-Os for arm,arm64,i386,
mips,riscv,s390 and x86_64.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 18a5a09d | 09-Jan-2023 |
Sven Schnelle <svens@linux.ibm.com> |
nolibc: add support for s390
Use arch-x86_64 as a template. Not really different, but
we have our own mmap syscall which takes a structure instead
of discrete arguments.
Signed-off-by: Sven Schnell
nolibc: add support for s390
Use arch-x86_64 as a template. Not really different, but
we have our own mmap syscall which takes a structure instead
of discrete arguments.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 00b18da4 | 09-Jan-2023 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: fix the O_* fcntl/open macro definitions for riscv
When RISCV port was imported in 5.2, the O_* macros were taken with
their octal value and written as-is in hex, resulting in the getd
tools/nolibc: fix the O_* fcntl/open macro definitions for riscv
When RISCV port was imported in 5.2, the O_* macros were taken with
their octal value and written as-is in hex, resulting in the getdents64()
to fail in nolibc-test.
Fixes: 582e84f7b779 ("tool headers nolibc: add RISCV support") #5.2
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 1bfbe1f3 | 09-Jan-2023 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: prevent gcc from making memset() loop over itself
When building on ARM in thumb mode with gcc-11.3 at -O2 or -O3,
nolibc-test segfaults during the select() tests. It turns out that at
tools/nolibc: prevent gcc from making memset() loop over itself
When building on ARM in thumb mode with gcc-11.3 at -O2 or -O3,
nolibc-test segfaults during the select() tests. It turns out that at
this level, gcc recognizes an opportunity for using memset() to zero
the fd_set, but it miscompiles it because it also recognizes a memset
pattern as well, and decides to call memset() from the memset() code:
000122bc <memset>:
122bc: b510 push {r4, lr}
122be: 0004 movs r4, r0
122c0: 2a00 cmp r2, #0
122c2: d003 beq.n 122cc <memset+0x10>
122c4: 23ff movs r3, #255 ; 0xff
122c6: 4019 ands r1, r3
122c8: f7ff fff8 bl 122bc <memset>
122cc: 0020 movs r0, r4
122ce: bd10 pop {r4, pc}
Simply placing an empty asm() statement inside the loop suffices to
avoid this.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 55abdd1f | 09-Jan-2023 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: fix missing includes causing build issues at -O0
After the nolibc includes were split to facilitate portability from
standard libcs, programs that include only what they need may miss
tools/nolibc: fix missing includes causing build issues at -O0
After the nolibc includes were split to facilitate portability from
standard libcs, programs that include only what they need may miss
some symbols which are needed by libgcc. This is the case for raise()
which is needed by the divide by zero code in some architectures for
example.
Regardless, being able to include only the apparently needed files is
convenient.
Instead of trying to move all exported definitions to a single file,
since this can change over time, this patch takes another approach
consisting in including the nolibc header at the end of all standard
include files. This way their types and functions are already known
at the moment of inclusion, and including any single one of them is
sufficient to bring all the required ones.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 184177c3 | 09-Jan-2023 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: restore mips branch ordering in the _start block
Depending on the compiler used and the optimization options, the sbrk()
test was crashing, both on real hardware (mips-24kc) and in qem
tools/nolibc: restore mips branch ordering in the _start block
Depending on the compiler used and the optimization options, the sbrk()
test was crashing, both on real hardware (mips-24kc) and in qemu. One
such example is kernel.org toolchain in version 11.3 optimizing at -Os.
Inspecting the sys_brk() call shows the following code:
0040047c <sys_brk>:
40047c: 24020fcd li v0,4045
400480: 27bdffe0 addiu sp,sp,-32
400484: 0000000c syscall
400488: 27bd0020 addiu sp,sp,32
40048c: 10e00001 beqz a3,400494 <sys_brk+0x18>
400490: 00021023 negu v0,v0
400494: 03e00008 jr ra
It is obviously wrong, the "negu" instruction is placed in beqz's
delayed slot, and worse, there's no nop nor instruction after the
return, so the next function's first instruction (addiu sip,sip,-32)
will also be executed as part of the delayed slot that follows the
return.
This is caused by the ".set noreorder" directive in the _start block,
that applies to the whole program. The compiler emits code without the
delayed slots and relies on the compiler to swap instructions when this
option is not set. Removing the option would require to change the
startup code in a way that wouldn't make it look like the resulting
code, which would not be easy to debug. Instead let's just save the
default ordering before changing it, and restore it at the end of the
_start block. Now the code is correct:
0040047c <sys_brk>:
40047c: 24020fcd li v0,4045
400480: 27bdffe0 addiu sp,sp,-32
400484: 0000000c syscall
400488: 10e00002 beqz a3,400494 <sys_brk+0x18>
40048c: 27bd0020 addiu sp,sp,32
400490: 00021023 negu v0,v0
400494: 03e00008 jr ra
400498: 00000000 nop
Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc") #5.0
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 16f5cea7 | 09-Jan-2023 |
Warner Losh <imp@bsdimp.com> |
tools/nolibc: Fix S_ISxxx macros
The mode field has the type encoded as an value in a field, not as a bit
mask. Mask the mode with S_IFMT instead of each type to test. Otherwise,
false positives are
tools/nolibc: Fix S_ISxxx macros
The mode field has the type encoded as an value in a field, not as a bit
mask. Mask the mode with S_IFMT instead of each type to test. Otherwise,
false positives are possible: eg S_ISDIR will return true for block
devices because S_IFDIR = 0040000 and S_IFBLK = 0060000 since mode is
masked with S_IFDIR instead of S_IFMT. These macros now match the
similar definitions in tools/include/uapi/linux/stat.h.
Signed-off-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| b3f4f51e | 21-Oct-2022 |
Rasmus Villemoes <linux@rasmusvillemoes.dk> |
tools/nolibc/string: Fix memcmp() implementation
The C standard says that memcmp() must treat the buffers as consisting
of "unsigned chars". If char happens to be unsigned, the casts are ok,
but the
tools/nolibc/string: Fix memcmp() implementation
The C standard says that memcmp() must treat the buffers as consisting
of "unsigned chars". If char happens to be unsigned, the casts are ok,
but then obviously the c1 variable can never contain a negative
value. And when char is signed, the casts are wrong, and there's still
a problem with using an 8-bit quantity to hold the difference, because
that can range from -255 to +255.
For example, assuming char is signed, comparing two 1-byte buffers,
one containing 0x00 and another 0x80, the current implementation would
return -128 for both memcmp(a, b, 1) and memcmp(b, a, 1), whereas one
of those should of course return something positive.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 8b53e83b | 19-Jul-2022 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: fix build warning in sys_mmap() when my_syscall6 is not defined
We return -ENOSYS when there's no syscall6() operation, but we must cast
it to void* to avoid a warning.
Signed-off-by:
tools/nolibc: fix build warning in sys_mmap() when my_syscall6 is not defined
We return -ENOSYS when there's no syscall6() operation, but we must cast
it to void* to avoid a warning.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 4f8126f3 | 28-May-2022 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: add a help target to list supported targets
The "help" target simply presents the list of supported targets
and the current set of variables being used to build the sysroot.
Since the
tools/nolibc: add a help target to list supported targets
The "help" target simply presents the list of supported targets
and the current set of variables being used to build the sysroot.
Since the help in tools/ suggests to use "install", which is
supported by most tools while such a target is not really relevant
here, an "install" target was also added, redirecting to "help".
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| fe20cad4 | 28-May-2022 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: make the default target build the headers
The help in "make -C tools" enumerates nolibc as a valid target so we
must at least make it do something. Let's make it do the equivalent
of "
tools/nolibc: make the default target build the headers
The help in "make -C tools" enumerates nolibc as a valid target so we
must at least make it do something. Let's make it do the equivalent
of "make headers" in that it will prepare a sysroot with the arch's
headers, but will not install the kernel's headers. This is the
minimum some tools will need when built with a full-blown toolchain
anyway.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 6a3ad243 | 28-May-2022 |
Willy Tarreau <w@1wt.eu> |
tools/nolibc: fix the makefile to also work as "make -C tools ..."
As reported by Linus, the nolibc's makefile is currently broken when
invoked as per the documented method (make -C tools nolibc_<ta
tools/nolibc: fix the makefile to also work as "make -C tools ..."
As reported by Linus, the nolibc's makefile is currently broken when
invoked as per the documented method (make -C tools nolibc_<target>),
because it now relies on the ARCH and OUTPUT variables that are not
set in this case.
This patch addresses this by sourcing subarch.include, and by
presetting OUTPUT to the current directory if not set. This is
sufficient to make the commands work both as a standalone target
and as a tools/ sub-target.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 4f2c9703 | 19-May-2022 |
Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org> |
tools/nolibc/stdio: Add format attribute to enable printf warnings
When we use printf and fprintf functions from the nolibc, we don't
get any warning from the compiler if we have the wrong arguments
tools/nolibc/stdio: Add format attribute to enable printf warnings
When we use printf and fprintf functions from the nolibc, we don't
get any warning from the compiler if we have the wrong arguments.
For example, the following calls will compile silently:
```
printf("%s %s\n", "aaa");
fprintf(stdout, "%s %s\n", "xxx", 1);
```
(Note the wrong arguments).
Those calls are undefined behavior. The compiler can help us warn
about the above mistakes by adding a `printf` format attribute to
those functions declaration. This patch adds it, and now it yields
these warnings for those mistakes:
```
warning: format `%s` expects a matching `char *` argument [-Wformat=]
warning: format `%s` expects argument of type `char *`, but argument 4 has type `int` [-Wformat=]
```
[ ammarfaizi2: Simplify the attribute placement. ]
Signed-off-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 11dbdaef | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc/string: Implement `strdup()` and `strndup()`
These functions are currently only available on architectures that have
my_syscall6() macro implemented. Since these functions use malloc(),
tools/nolibc/string: Implement `strdup()` and `strndup()`
These functions are currently only available on architectures that have
my_syscall6() macro implemented. Since these functions use malloc(),
malloc() uses mmap(), mmap() depends on my_syscall6() macro.
On architectures that don't support my_syscall6(), these function will
always return NULL with errno set to ENOSYS.
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| b26823c1 | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc/string: Implement `strnlen()`
size_t strnlen(const char *str, size_t maxlen);
The strnlen() function returns the number of bytes in the string
pointed to by sstr, excluding the termi
tools/nolibc/string: Implement `strnlen()`
size_t strnlen(const char *str, size_t maxlen);
The strnlen() function returns the number of bytes in the string
pointed to by sstr, excluding the terminating null byte ('\0'), but at
most maxlen. In doing this, strnlen() looks only at the first maxlen
characters in the string pointed to by str and never beyond str[maxlen-1].
The first use case of this function is for determining the memory
allocation size in the strndup() function.
Link: https://lore.kernel.org/lkml/CAOG64qMpEMh+EkOfjNdAoueC+uQyT2Uv3689_sOr37-JxdJf4g@mail.gmail.com
Suggested-by: Alviro Iskandar Setiawan <alviro.iskandar@gnuweeb.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 0e0ff638 | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`
Implement basic dynamic allocator functions. These functions are
currently only available on architectures that have n
tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()`
Implement basic dynamic allocator functions. These functions are
currently only available on architectures that have nolibc mmap()
syscall implemented. These are not a super-fast memory allocator,
but at least they can satisfy basic needs for having heap without
libc.
Cc: David Laight <David.Laight@ACULAB.COM>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 5a18d07c | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc/types: Implement `offsetof()` and `container_of()` macro
Implement `offsetof()` and `container_of()` macro. The first use case
of these macros is for `malloc()`, `realloc()` and `free()
tools/nolibc/types: Implement `offsetof()` and `container_of()` macro
Implement `offsetof()` and `container_of()` macro. The first use case
of these macros is for `malloc()`, `realloc()` and `free()`.
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 544fa1a2 | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc/sys: Implement `mmap()` and `munmap()`
Implement mmap() and munmap(). Currently, they are only available for
architecures that have my_syscall6 macro. For architectures that don't
have,
tools/nolibc/sys: Implement `mmap()` and `munmap()`
Implement mmap() and munmap(). Currently, they are only available for
architecures that have my_syscall6 macro. For architectures that don't
have, this function will return -1 with errno set to ENOSYS (Function
not implemented).
This has been tested on x86 and i386.
Notes for i386:
1) The common mmap() syscall implementation uses __NR_mmap2 instead
of __NR_mmap.
2) The offset must be shifted-right by 12-bit.
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| f4738ff7 | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc: i386: Implement syscall with 6 arguments
On i386, the 6th argument of syscall goes in %ebp. However, both Clang
and GCC cannot use %ebp in the clobber list and in the "r" constraint
wi
tools/nolibc: i386: Implement syscall with 6 arguments
On i386, the 6th argument of syscall goes in %ebp. However, both Clang
and GCC cannot use %ebp in the clobber list and in the "r" constraint
without using -fomit-frame-pointer. To make it always available for
any kind of compilation, the below workaround is implemented.
1) Push the 6-th argument.
2) Push %ebp.
3) Load the 6-th argument from 4(%esp) to %ebp.
4) Do the syscall (int $0x80).
5) Pop %ebp (restore the old value of %ebp).
6) Add %esp by 4 (undo the stack pointer).
Cc: x86@kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/lkml/2e335ac54db44f1d8496583d97f9dab0@AcuMS.aculab.com
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|
| 1590c598 | 29-Mar-2022 |
Ammar Faizi <ammarfaizi2@gnuweeb.org> |
tools/nolibc: Remove .global _start from the entry point code
Building with clang yields the following error:
```
<inline asm>:3:1: error: _start changed binding to STB_GLOBAL
.global _start
^
tools/nolibc: Remove .global _start from the entry point code
Building with clang yields the following error:
```
<inline asm>:3:1: error: _start changed binding to STB_GLOBAL
.global _start
^
1 error generated.
```
Make sure only specify one between `.global _start` and `.weak _start`.
Remove `.global _start`.
Cc: llvm@lists.linux.dev
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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|