Differential D32960 Diff 99403 sys/amd64/ia32/ia32_sigtramp.S

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sys/amd64/ia32/ia32_sigtramp.S

	/*-			/*-
	* Copyright (c) 2003 Peter Wemm			* Copyright (c) 2003 Peter Wemm
	* All rights reserved.			* All rights reserved.
	*			*
				* Copyright (c) 2021 The FreeBSD Foundation
				*
				* Portions of this software were developed by Konstantin Belousov
				* under sponsorship from the FreeBSD Foundation.
				*
	* Redistribution and use in source and binary forms, with or without			* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions			* modification, are permitted provided that the following conditions
	* are met:			* are met:
	* 1. Redistributions of source code must retain the above copyright			* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.			* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright			* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the			* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.			* documentation and/or other materials provided with the distribution.
	Show All 14 Lines
	*/			*/

	#include <machine/asmacros.h>			#include <machine/asmacros.h>
	#include <sys/syscall.h>			#include <sys/syscall.h>

	#include "ia32_assym.h"			#include "ia32_assym.h"

	.text			.text
	.code32
	/*			/*
	* Signal trampoline, copied to top of user stack			* Signal trampoline, mapped as vdso into shared page, or copied to
	* XXX may need to be MD to match backend sendsig handoff protocol			* top of user stack for old binaries.
	*/			*/
	ALIGN_TEXT			ALIGN_TEXT
	.globl ia32_sigcode			.globl __vdso_ia32_sigcode
	ia32_sigcode:			__vdso_ia32_sigcode:
				.cfi_startproc
				.cfi_signal_frame
				.cfi_def_cfa %esp, 0
				.cfi_offset %edi, IA32_SIGF_UC + IA32_UC_EDI
				.cfi_offset %esi, IA32_SIGF_UC + IA32_UC_ESI
				emasteUnsubmitted Done Inline Actions did not verify these emaste: did not verify these
				.cfi_offset %ebp, IA32_SIGF_UC + IA32_UC_EBP
				.cfi_offset %ebx, IA32_SIGF_UC + IA32_UC_EBX
				.cfi_offset %edx, IA32_SIGF_UC + IA32_UC_EDX
				.cfi_offset %ecx, IA32_SIGF_UC + IA32_UC_ECX
				.cfi_offset %eax, IA32_SIGF_UC + IA32_UC_EAX
				.cfi_offset %eip, IA32_SIGF_UC + IA32_UC_EIP
				.cfi_offset %esp, IA32_SIGF_UC + IA32_UC_ESP
				jhbUnsubmitted Done Inline Actions Similar question about segment registers, fsbase/gsbase (GDB uses those for TLS), and flags. jhb: Similar question about segment registers, fsbase/gsbase (GDB uses those for TLS), and flags.
	calll *IA32_SIGF_HANDLER(%esp)			calll *IA32_SIGF_HANDLER(%esp)
	leal IA32_SIGF_UC(%esp),%eax /* get ucontext */			leal IA32_SIGF_UC(%esp),%eax /* get ucontext */
	pushl %eax			pushl %eax
				.cfi_def_cfa %esp, 4
	movl $SYS_sigreturn,%eax			movl $SYS_sigreturn,%eax
	pushl %eax /* junk to fake return addr. */			pushl %eax /* junk to fake return addr. */
				.cfi_def_cfa %esp, 8
	int $0x80 /* enter kernel with args */			int $0x80 /* enter kernel with args */
	/* on stack */			/* on stack */
	1:			1:
	jmp 1b			jmp 1b
				.cfi_endproc

	#ifdef COMPAT_FREEBSD4			#ifdef COMPAT_FREEBSD4
	ALIGN_TEXT			ALIGN_TEXT
	freebsd4_ia32_sigcode:			.globl __vdso_freebsd4_ia32_sigcode
				__vdso_freebsd4_ia32_sigcode:
	calll *IA32_SIGF_HANDLER(%esp)			calll *IA32_SIGF_HANDLER(%esp)
	leal IA32_SIGF_UC4(%esp),%eax/* get ucontext */			leal IA32_SIGF_UC4(%esp),%eax/* get ucontext */
	pushl %eax			pushl %eax
	movl $344,%eax /* 4.x SYS_sigreturn */			movl $344,%eax /* 4.x SYS_sigreturn */
	pushl %eax /* junk to fake return addr. */			pushl %eax /* junk to fake return addr. */
	int $0x80 /* enter kernel with args */			int $0x80 /* enter kernel with args */
	/* on stack */			/* on stack */
	1:			1:
	jmp 1b			jmp 1b
	#endif			#endif

	#ifdef COMPAT_43			#ifdef COMPAT_43
	ALIGN_TEXT			ALIGN_TEXT
	ia32_osigcode:			.globl __vdso_ia32_osigcode
				__vdso_ia32_osigcode:
	calll IA32_SIGF_HANDLER(%esp)/ call signal handler */			calll IA32_SIGF_HANDLER(%esp)/ call signal handler */
	leal IA32_SIGF_SC(%esp),%eax /* get sigcontext */			leal IA32_SIGF_SC(%esp),%eax /* get sigcontext */
	pushl %eax			pushl %eax
	movl $103,%eax /* 3.x SYS_sigreturn */			movl $103,%eax /* 3.x SYS_sigreturn */
	pushl %eax /* junk to fake return addr. */			pushl %eax /* junk to fake return addr. */
	int $0x80 /* enter kernel with args */			int $0x80 /* enter kernel with args */
	1:			1:
	jmp 1b			jmp 1b

	/*			/*
	* Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls			* Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls
	* don't change the interrupt mask, so if this one went directly to the			* don't change the interrupt mask, so if this one went directly to the
	* kernel then there would be a window with interrupts enabled in kernel			* kernel then there would be a window with interrupts enabled in kernel
	* mode, and all interrupt handlers would have to be almost as complicated			* mode, and all interrupt handlers would have to be almost as complicated
	* as the NMI handler to support this.			* as the NMI handler to support this.
	*			*
	* Instead, convert the lcall to an int0x80 call. The kernel does most			* Instead, convert the lcall to an int0x80 call. The kernel does most
	* of the conversion by popping the lcall return values off the user			* of the conversion by popping the lcall return values off the user
	* stack and returning to them instead of to here, except when the			* stack and returning to them instead of to here, except when the
	* conversion itself fails. Adjusting the stack here is impossible for			* conversion itself fails. Adjusting the stack here is impossible for
	* vfork() and harder for other syscalls.			* vfork() and harder for other syscalls.
	*/			*/
	ALIGN_TEXT			ALIGN_TEXT
	lcall_tramp:			.globl __vdso_lcall_tramp
				__vdso_lcall_tramp:
	int $0x80			int $0x80
	1: jmp 1b			1: jmp 1b
	#endif			#endif
				.p2align 1
	ALIGN_TEXT
	esigcode:

	.data
	.globl sz_ia32_sigcode
	sz_ia32_sigcode:
	.long esigcode-ia32_sigcode
	#ifdef COMPAT_FREEBSD4
	.globl sz_freebsd4_ia32_sigcode
	sz_freebsd4_ia32_sigcode:
	.long esigcode-freebsd4_ia32_sigcode
	#endif
	#ifdef COMPAT_43
	.globl sz_ia32_osigcode
	sz_ia32_osigcode:
	.long esigcode-ia32_osigcode
	.globl sz_lcall_tramp
	sz_lcall_tramp:
	.long esigcode-lcall_tramp
	#endif