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From: "Paul E. McKenney" <[email protected]>
To: [email protected]
Cc: [email protected], [email protected], [email protected],
	Ammar Faizi <[email protected]>,
	[email protected], [email protected],
	David Laight <[email protected]>, Willy Tarreau <[email protected]>,
	"Paul E . McKenney" <[email protected]>
Subject: [PATCH nolibc 56/61] tools/nolibc: i386: Implement syscall with 6 arguments
Date: Mon, 18 Apr 2022 17:42:20 -0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <20220419004219.GA3952301@paulmck-ThinkPad-P17-Gen-1>

From: Ammar Faizi <[email protected]>

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: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/lkml/[email protected]
Suggested-by: David Laight <[email protected]>
Acked-by: Willy Tarreau <[email protected]>
Signed-off-by: Ammar Faizi <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
---
 tools/include/nolibc/arch-i386.h | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tools/include/nolibc/arch-i386.h b/tools/include/nolibc/arch-i386.h
index 10aada40680d..d7e7212346e2 100644
--- a/tools/include/nolibc/arch-i386.h
+++ b/tools/include/nolibc/arch-i386.h
@@ -167,6 +167,29 @@ struct sys_stat_struct {
 	_ret;                                                                 \
 })
 
+#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6)	\
+({								\
+	long _eax  = (long)(num);				\
+	long _arg6 = (long)(arg6); /* Always in memory */	\
+	__asm__ volatile (					\
+		"pushl	%[_arg6]\n\t"				\
+		"pushl	%%ebp\n\t"				\
+		"movl	4(%%esp),%%ebp\n\t"			\
+		"int	$0x80\n\t"				\
+		"popl	%%ebp\n\t"				\
+		"addl	$4,%%esp\n\t"				\
+		: "+a"(_eax)		/* %eax */		\
+		: "b"(arg1),		/* %ebx */		\
+		  "c"(arg2),		/* %ecx */		\
+		  "d"(arg3),		/* %edx */		\
+		  "S"(arg4),		/* %esi */		\
+		  "D"(arg5),		/* %edi */		\
+		  [_arg6]"m"(_arg6)	/* memory */		\
+		: "memory", "cc"				\
+	);							\
+	_eax;							\
+})
+
 /* startup code */
 /*
  * i386 System V ABI mandates:
-- 
2.31.1.189.g2e36527f23


  parent reply	other threads:[~2022-04-19  0:42 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-19  0:42 [PATCH nolibc 0/61] nolibc updates for v5.19 Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 01/61] tools/nolibc: use pselect6 on RISCV Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 02/61] tools/nolibc: guard the main file against multiple inclusion Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 03/61] tools/nolibc/std: move the standard type definitions to std.h Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 04/61] tools/nolibc/types: split syscall-specific definitions into their own files Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 05/61] tools/nolibc/arch: split arch-specific code into individual files Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 06/61] tools/nolibc/sys: split the syscall definitions into their own file Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 07/61] tools/nolibc/stdlib: extract the stdlib-specific functions to " Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 08/61] tools/nolibc/string: split the string functions into string.h Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 09/61] tools/nolibc/ctype: split the is* functions to ctype.h Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 10/61] tools/nolibc/ctype: add the missing is* functions Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 11/61] tools/nolibc/types: move the FD_* functions to macros in types.h Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 12/61] tools/nolibc/types: make FD_SETSIZE configurable Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 13/61] tools/nolibc/types: move makedev to types.h and make it a macro Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 14/61] tools/nolibc/stdlib: move ltoa() to stdlib.h Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 15/61] tools/nolibc/stdlib: replace the ltoa() function with more efficient ones Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 16/61] tools/nolibc/stdlib: add i64toa() and u64toa() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 17/61] tools/nolibc/stdlib: add utoh() and u64toh() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 18/61] tools/nolibc/stdio: add a minimal set of stdio functions Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 19/61] tools/nolibc/stdio: add stdin/stdout/stderr and fget*/fput* functions Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 20/61] tools/nolibc/stdio: add fwrite() to stdio Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 21/61] tools/nolibc/stdio: add a minimal [vf]printf() implementation Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 22/61] tools/nolibc/types: define EXIT_SUCCESS and EXIT_FAILURE Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 23/61] tools/nolibc/stdio: add perror() to report the errno value Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 24/61] tools/nolibc/sys: make open() take a vararg on the 3rd argument Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 25/61] tools/nolibc/stdlib: avoid a 64-bit shift in u64toh_r() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 26/61] tools/nolibc/stdlib: make raise() use the lower level syscalls only Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 27/61] tools/nolibc/sys: make getpgrp(), getpid(), gettid() not set errno Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 28/61] tools/nolibc/string: use unidirectional variants for memcpy() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 29/61] tools/nolibc/string: slightly simplify memmove() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 30/61] tools/nolibc/string: add strncpy() and strlcpy() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 31/61] tools/nolibc/string: add tiny versions of strncat() and strlcat() Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 32/61] tools/nolibc: move exported functions to their own section Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 33/61] tools/nolibc/arch: mark the _start symbol as weak Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 34/61] tools/nolibc/types: define PATH_MAX and MAXPATHLEN Paul E. McKenney
2022-04-19  0:41 ` [PATCH nolibc 35/61] tools/nolibc/string: export memset() and memmove() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 36/61] tools/nolibc/errno: extract errno.h from sys.h Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 37/61] tools/nolibc/unistd: extract msleep(), sleep(), tcsetpgrp() to unistd.h Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 38/61] tools/nolibc/unistd: add usleep() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 39/61] tools/nolibc/signal: move raise() to signal.h Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 40/61] tools/nolibc/time: create time.h with time() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 41/61] tools/nolibc: also mention how to build by just setting the include path Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 42/61] tools/nolibc/stdlib: implement abort() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 43/61] tools/nolibc/stdio: make printf(%s) accept NULL Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 44/61] tools/nolibc/stdlib: add a simple getenv() implementation Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 45/61] tools/nolibc/stdio: add support for '%p' to vfprintf() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 46/61] tools/nolibc/string: add strcmp() and strncmp() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 47/61] tools/nolibc/sys: add syscall definition for getppid() Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 48/61] tools/nolibc/types: add poll() and waitpid() flag definitions Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 49/61] tools/nolibc: add a makefile to install headers Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 50/61] tools/nolibc: add the nolibc subdir to the common Makefile Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 51/61] tools/nolibc/string: do not use __builtin_strlen() at -O0 Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 52/61] tools/nolibc/stdlib: only reference the external environ when inlined Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 53/61] tools/nolibc: x86-64: Update System V ABI document link Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 54/61] tools/nolibc: Replace `asm` with `__asm__` Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 55/61] tools/nolibc: Remove .global _start from the entry point code Paul E. McKenney
2022-04-19  0:42 ` Paul E. McKenney [this message]
2022-04-19  0:42 ` [PATCH nolibc 57/61] tools/nolibc/sys: Implement `mmap()` and `munmap()` Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 58/61] tools/nolibc/types: Implement `offsetof()` and `container_of()` macro Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 59/61] tools/nolibc/stdlib: Implement `malloc()`, `calloc()`, `realloc()` and `free()` Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 60/61] tools/nolibc/string: Implement `strnlen()` Paul E. McKenney
2022-04-19  0:42 ` [PATCH nolibc 61/61] tools/nolibc/string: Implement `strdup()` and `strndup()` Paul E. McKenney

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