Commit 8dc7f022 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc: remove partial register save logic 



All subarchitectures always save all GPRs to pt_regs interrupt frames
now. Remove FULL_REGS and associated bits.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210316104206.407354-11-npiggin@gmail.com
parent c45ba4f4

arch/powerpc/include/asm/ptrace.h

+2 −15
Original line number Diff line number Diff line
@@ -188,29 +188,16 @@ static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 
#ifdef __powerpc64__

#define TRAP_FLAGS_MASK		0x10

#define TRAP(regs)		((regs)->trap & ~TRAP_FLAGS_MASK)

#define FULL_REGS(regs)		true

#define SET_FULL_REGS(regs)	do { } while (0)

#define CHECK_FULL_REGS(regs)	do { } while (0)

#define NV_REG_POISON		0xdeadbeefdeadbeefUL

#else

/*

 * We use the least-significant bit of the trap field to indicate

 * whether we have saved the full set of registers, or only a

 * partial set.  A 1 there means the partial set.

 * On 4xx we use the next bit to indicate whether the exception

 * On 4xx we use bit 1 in the trap word to indicate whether the exception

 * is a critical exception (1 means it is).

 */

#define TRAP_FLAGS_MASK		0x1F

#define TRAP_FLAGS_MASK		0x1E

#define TRAP(regs)		((regs)->trap & ~TRAP_FLAGS_MASK)

#define FULL_REGS(regs)		true

#define SET_FULL_REGS(regs)	do { } while (0)

#define IS_CRITICAL_EXC(regs)	(((regs)->trap & 2) != 0)

#define IS_MCHECK_EXC(regs)	(((regs)->trap & 4) != 0)

#define IS_DEBUG_EXC(regs)	(((regs)->trap & 8) != 0)

#define NV_REG_POISON		0xdeadbeef

#define CHECK_FULL_REGS(regs)						      \

do {									      \

} while (0)

#endif /* __powerpc64__ */



static __always_inline void set_trap(struct pt_regs *regs, unsigned long val)

arch/powerpc/kernel/align.c

+0 −6
Original line number Diff line number Diff line
@@ -304,12 +304,6 @@ int fix_alignment(struct pt_regs *regs) 
	struct instruction_op op;

	int r, type;



	/*

	 * We require a complete register set, if not, then our assembly

	 * is broken

	 */

	CHECK_FULL_REGS(regs);



	if (is_kernel_addr(regs->nip))

		r = probe_kernel_read_inst(&instr, (void *)regs->nip);

	else

arch/powerpc/kernel/interrupt.c

+0 −3
Original line number Diff line number Diff line
@@ -51,7 +51,6 @@ notrace long system_call_exception(long r3, long r4, long r5, 
	if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))

		BUG_ON(!(regs->msr & MSR_RI));

	BUG_ON(!(regs->msr & MSR_PR));

	BUG_ON(!FULL_REGS(regs));

	BUG_ON(arch_irq_disabled_regs(regs));



#ifdef CONFIG_PPC_PKEY
@@ -365,7 +364,6 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned 
	if (!IS_ENABLED(CONFIG_BOOKE) && !IS_ENABLED(CONFIG_40x))

		BUG_ON(!(regs->msr & MSR_RI));

	BUG_ON(!(regs->msr & MSR_PR));

	BUG_ON(!FULL_REGS(regs));

	BUG_ON(arch_irq_disabled_regs(regs));

	CT_WARN_ON(ct_state() == CONTEXT_USER);
@@ -445,7 +443,6 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign 
	    unlikely(!(regs->msr & MSR_RI)))

		unrecoverable_exception(regs);

	BUG_ON(regs->msr & MSR_PR);

	BUG_ON(!FULL_REGS(regs));

	/*

	 * CT_WARN_ON comes here via program_check_exception,

	 * so avoid recursion.

arch/powerpc/kernel/process.c

+0 −12
Original line number Diff line number Diff line
@@ -1448,11 +1448,9 @@ static void print_msr_bits(unsigned long val) 
#ifdef CONFIG_PPC64

#define REG		"%016lx"

#define REGS_PER_LINE	4

#define LAST_VOLATILE	13

#else

#define REG		"%08lx"

#define REGS_PER_LINE	8

#define LAST_VOLATILE	12

#endif



static void __show_regs(struct pt_regs *regs)
@@ -1488,8 +1486,6 @@ static void __show_regs(struct pt_regs *regs) 
		if ((i % REGS_PER_LINE) == 0)

			pr_cont("\nGPR%02d: ", i);

		pr_cont(REG " ", regs->gpr[i]);

		if (i == LAST_VOLATILE && !FULL_REGS(regs))

			break;

	}

	pr_cont("\n");

	/*
@@ -1692,7 +1688,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, 
	} else {

		/* user thread */

		struct pt_regs *regs = current_pt_regs();

		CHECK_FULL_REGS(regs);

		*childregs = *regs;

		if (usp)

			childregs->gpr[1] = usp;
@@ -1797,13 +1792,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 
	regs->ccr = 0;

	regs->gpr[1] = sp;



	/*

	 * We have just cleared all the nonvolatile GPRs, so make

	 * FULL_REGS(regs) return true.  This is necessary to allow

	 * ptrace to examine the thread immediately after exec.

	 */

	SET_FULL_REGS(regs);



#ifdef CONFIG_PPC32

	regs->mq = 0;

	regs->nip = start;

arch/powerpc/kernel/ptrace/ptrace-view.c

+0 −21
Original line number Diff line number Diff line
@@ -221,17 +221,9 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset, 
#ifdef CONFIG_PPC64

	struct membuf to_softe = membuf_at(&to, offsetof(struct pt_regs, softe));

#endif

	int i;



	if (target->thread.regs == NULL)

		return -EIO;



	if (!FULL_REGS(target->thread.regs)) {

		/* We have a partial register set.  Fill 14-31 with bogus values */

		for (i = 14; i < 32; i++)

			target->thread.regs->gpr[i] = NV_REG_POISON;

	}



	membuf_write(&to, target->thread.regs, sizeof(struct user_pt_regs));



	membuf_store(&to_msr, get_user_msr(target));
@@ -252,8 +244,6 @@ static int gpr_set(struct task_struct *target, const struct user_regset *regset, 
	if (target->thread.regs == NULL)

		return -EIO;



	CHECK_FULL_REGS(target->thread.regs);



	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

				 target->thread.regs,

				 0, PT_MSR * sizeof(reg));
@@ -729,19 +719,9 @@ static int gpr32_get(struct task_struct *target, 
		     const struct user_regset *regset,

		     struct membuf to)

{

	int i;



	if (target->thread.regs == NULL)

		return -EIO;



	if (!FULL_REGS(target->thread.regs)) {

		/*

		 * We have a partial register set.

		 * Fill 14-31 with bogus values.

		 */

		for (i = 14; i < 32; i++)

			target->thread.regs->gpr[i] = NV_REG_POISON;

	}

	return gpr32_get_common(target, regset, to,

			&target->thread.regs->gpr[0]);

}
@@ -754,7 +734,6 @@ static int gpr32_set(struct task_struct *target, 
	if (target->thread.regs == NULL)

		return -EIO;



	CHECK_FULL_REGS(target->thread.regs);

	return gpr32_set_common(target, regset, pos, count, kbuf, ubuf,

			&target->thread.regs->gpr[0]);

}