From: Ammar Faizi <[email protected]>
To: Willy Tarreau <[email protected]>
Cc: David Laight <[email protected]>,
"Paul E. McKenney" <[email protected]>,
Alviro Iskandar Setiawan <[email protected]>,
Nugraha <[email protected]>,
Linux Kernel Mailing List <[email protected]>,
GNU/Weeb Mailing List <[email protected]>,
"[email protected]" <[email protected]>,
"[email protected]" <[email protected]>
Subject: Re: [RFC PATCH v2 3/8] tools/nolibc: i386: Implement syscall with 6 arguments
Date: Tue, 22 Mar 2022 20:37:03 +0700 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 3/22/22 8:34 PM, Willy Tarreau wrote:
>> I turned out GCC refuses to use "rm" if we compile without -fomit-frame-pointer
>> (e.g. without optimization / -O0). So I will still use "m" here.
>
> OK that's fine. then you can probably simplify it like this:
>
> long _arg6 = (long)(arg6); /* Might be in memory */ \
> \
> asm volatile ( \
> "pushl %%ebp\n\t" \
> "movl %[_arg6], %%ebp\n\t" \
> "int $0x80\n\t" \
> "popl %%ebp\n\t" \
> : "=a"(_ret) \
> : "r"(_num), "r"(_arg1), "r"(_arg2), "r"(_arg3), \
> "r"(_arg4),"r"(_arg5), [_arg6]"m"(_arg6) \
> : "memory", "cc" \
> ); \
>
> See ? no more push, no more addl, direct load from memory.
Uggh... I crafted the same code like you suggested before, but then
I realized it's buggy, it's buggy because %[_arg6] may live in N(%esp).
When you pushl %ebp, the %esp changes, N(%esp) no longer points to the
6-th argument.
--
Ammar Faizi
next prev parent reply other threads:[~2022-03-22 13:37 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-22 10:21 [RFC PATCH v2 0/8] Add dynamic memory allocator support for nolibc Ammar Faizi
2022-03-22 10:21 ` [RFC PATCH v2 1/8] tools/nolibc: x86-64: Update System V ABI document link Ammar Faizi
2022-03-22 10:21 ` [RFC PATCH v2 2/8] tools/nolibc: Remove .global _start from the entry point code Ammar Faizi
2022-03-22 17:09 ` Nick Desaulniers
2022-03-22 17:25 ` Willy Tarreau
2022-03-22 17:30 ` Nick Desaulniers
2022-03-22 17:58 ` Willy Tarreau
2022-03-22 18:07 ` Nick Desaulniers
2022-03-22 18:24 ` Willy Tarreau
2022-03-22 18:38 ` Nick Desaulniers
2022-03-22 10:21 ` [RFC PATCH v2 3/8] tools/nolibc: i386: Implement syscall with 6 arguments Ammar Faizi
2022-03-22 10:57 ` David Laight
2022-03-22 11:23 ` Willy Tarreau
2022-03-22 11:39 ` David Laight
2022-03-22 12:02 ` Ammar Faizi
2022-03-22 12:07 ` Ammar Faizi
2022-03-22 12:13 ` Willy Tarreau
2022-03-22 13:26 ` Ammar Faizi
2022-03-22 13:34 ` Willy Tarreau
2022-03-22 13:37 ` Ammar Faizi [this message]
2022-03-22 13:39 ` David Laight
2022-03-22 13:41 ` Willy Tarreau
2022-03-22 13:45 ` Ammar Faizi
2022-03-22 13:54 ` Ammar Faizi
2022-03-22 13:56 ` Ammar Faizi
2022-03-22 14:02 ` Willy Tarreau
2022-03-22 13:37 ` David Laight
2022-03-22 14:47 ` Alviro Iskandar Setiawan
2022-03-22 15:11 ` David Laight
2022-03-23 6:29 ` Ammar Faizi
2022-03-23 6:32 ` Ammar Faizi
2022-03-23 7:10 ` Willy Tarreau
2022-03-22 10:21 ` [RFC PATCH v2 4/8] tools/nolibc/sys: Implement `mmap()` and `munmap()` Ammar Faizi
2022-03-22 10:21 ` [RFC PATCH v2 5/8] tools/nolibc/types: Implement `offsetof()` and `container_of()` macro Ammar Faizi
2022-03-22 10:21 ` [RFC PATCH v2 6/8] tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()` Ammar Faizi
2022-03-22 11:52 ` David Laight
2022-03-22 12:18 ` Ammar Faizi
2022-03-22 12:36 ` Alviro Iskandar Setiawan
2022-03-22 12:42 ` Ammar Faizi
2022-03-22 12:21 ` Willy Tarreau
2022-03-22 10:21 ` [RFC PATCH v2 7/8] tools/nolibc/string: Implement `strnlen()` Ammar Faizi
2022-03-22 10:21 ` [RFC PATCH v2 8/8] tools/include/string: Implement `strdup()` and `strndup()` Ammar Faizi
2022-03-22 11:27 ` [RFC PATCH v2 0/8] Add dynamic memory allocator support for nolibc Willy Tarreau
2022-03-22 12:43 ` Ammar Faizi
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