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55bb9480f9
Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366 there are 3 golden rules for (not) restarting syscalls: " What we need to guarantee is * restarts do not happen on signals caught in interrupts or exceptions * restarts do not happen on signals caught in sigreturn() * restart should happen only once, even if we get through do_signal() many times." ARC Port already handled #1, this patch fixes #2 and #3. We use the additional state in pt_regs->orig_r8 to ckh if restarting has already been done once. Thanks to Al Viro for spotting this. Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Al Viro <viro@ZenIV.linux.org.uk>
159 lines
3.8 KiB
C
159 lines
3.8 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Amit Bhor, Sameer Dhavale: Codito Technologies 2004
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*/
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#ifndef __ASM_ARC_PTRACE_H
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#define __ASM_ARC_PTRACE_H
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#ifdef __KERNEL__
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#ifndef __ASSEMBLY__
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/* THE pt_regs: Defines how regs are saved during entry into kernel */
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struct pt_regs {
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/*
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* 1 word gutter after reg-file has been saved
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* Technically not needed, Since SP always points to a "full" location
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* (vs. "empty"). But pt_regs is shared with tools....
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*/
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long res;
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/* Real registers */
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long bta; /* bta_l1, bta_l2, erbta */
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long lp_start;
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long lp_end;
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long lp_count;
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long status32; /* status32_l1, status32_l2, erstatus */
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long ret; /* ilink1, ilink2 or eret */
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long blink;
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long fp;
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long r26; /* gp */
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long r12;
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long r11;
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long r10;
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long r9;
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long r8;
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long r7;
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long r6;
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long r5;
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long r4;
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long r3;
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long r2;
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long r1;
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long r0;
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long sp; /* user/kernel sp depending on where we came from */
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long orig_r0;
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/*to distinguish bet excp, syscall, irq */
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union {
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#ifdef CONFIG_CPU_BIG_ENDIAN
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/* so that assembly code is same for LE/BE */
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unsigned long orig_r8:16, event:16;
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#else
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unsigned long event:16, orig_r8:16;
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#endif
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long orig_r8_word;
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};
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};
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/* Callee saved registers - need to be saved only when you are scheduled out */
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struct callee_regs {
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long res; /* Again this is not needed */
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long r25;
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long r24;
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long r23;
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long r22;
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long r21;
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long r20;
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long r19;
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long r18;
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long r17;
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long r16;
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long r15;
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long r14;
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long r13;
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};
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#define instruction_pointer(regs) ((regs)->ret)
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#define profile_pc(regs) instruction_pointer(regs)
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/* return 1 if user mode or 0 if kernel mode */
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#define user_mode(regs) (regs->status32 & STATUS_U_MASK)
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#define user_stack_pointer(regs)\
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({ unsigned int sp; \
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if (user_mode(regs)) \
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sp = (regs)->sp;\
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else \
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sp = -1; \
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sp; \
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})
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#define in_syscall(regs) (regs->event & orig_r8_IS_SCALL)
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#define in_brkpt_trap(regs) (regs->event & orig_r8_IS_BRKPT)
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#define syscall_wont_restart(regs) (regs->event |= orig_r8_IS_SCALL_RESTARTED)
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#define syscall_restartable(regs) !(regs->event & orig_r8_IS_SCALL_RESTARTED)
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#define current_pt_regs() \
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({ \
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/* open-coded current_thread_info() */ \
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register unsigned long sp asm ("sp"); \
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unsigned long pg_start = (sp & ~(THREAD_SIZE - 1)); \
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(struct pt_regs *)(pg_start + THREAD_SIZE - 4) - 1; \
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})
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#endif /* !__ASSEMBLY__ */
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#define orig_r8_IS_SCALL 0x0001
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#define orig_r8_IS_SCALL_RESTARTED 0x0002
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#define orig_r8_IS_BRKPT 0x0004
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#define orig_r8_IS_EXCPN 0x0004
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#define orig_r8_IS_IRQ1 0x0010
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#define orig_r8_IS_IRQ2 0x0020
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#endif /* __KERNEL__ */
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#ifndef __ASSEMBLY__
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/*
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* Userspace ABI: Register state needed by
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* -ptrace (gdbserver)
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* -sigcontext (SA_SIGNINFO signal frame)
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*
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* This is to decouple pt_regs from user-space ABI, to be able to change it
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* w/o affecting the ABI.
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* Although the layout (initial padding) is similar to pt_regs to have some
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* optimizations when copying pt_regs to/from user_regs_struct.
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*
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* Also, sigcontext only care about the scratch regs as that is what we really
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* save/restore for signal handling.
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*/
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struct user_regs_struct {
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struct scratch {
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long pad;
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long bta, lp_start, lp_end, lp_count;
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long status32, ret, blink, fp, gp;
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long r12, r11, r10, r9, r8, r7, r6, r5, r4, r3, r2, r1, r0;
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long sp;
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} scratch;
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struct callee {
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long pad;
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long r25, r24, r23, r22, r21, r20;
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long r19, r18, r17, r16, r15, r14, r13;
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} callee;
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long efa; /* break pt addr, for break points in delay slots */
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long stop_pc; /* give dbg stop_pc directly after checking orig_r8 */
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};
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#endif /* !__ASSEMBLY__ */
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#endif /* __ASM_PTRACE_H */
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