Commit ac4e61c7 authored by Paul Walmsley's avatar Paul Walmsley
Browse files

riscv: ptrace: expand "LP" references to "branch landing pads" in uapi headers 

Per Linus' comments about the unreadability of abbreviations such as
"LP", rename the RISC-V ptrace landing pad CFI macro names to be more
explicit.  This primarily involves expanding "LP" in the names to some
variant of "branch landing pad."

Link: https://lore.kernel.org/linux-riscv/CAHk-=whhSLGZAx3N5jJpb4GLFDqH_QvS07D+6BnkPWmCEzTAgw@mail.gmail.com/


Cc: Deepak Gupta <debug@rivosinc.com>
Signed-off-by: default avatarPaul Walmsley <pjw@kernel.org>
parent a6ede084

arch/riscv/include/uapi/asm/ptrace.h

+11 −9
Original line number Diff line number Diff line
@@ -132,23 +132,25 @@ struct __sc_riscv_cfi_state { 
	unsigned long ss_ptr;   /* shadow stack pointer */

};



#define PTRACE_CFI_LP_EN_BIT	0

#define PTRACE_CFI_LP_LOCK_BIT	1

#define PTRACE_CFI_ELP_BIT	2

#define PTRACE_CFI_BRANCH_LANDING_PAD_EN_BIT		0

#define PTRACE_CFI_BRANCH_LANDING_PAD_LOCK_BIT		1

#define PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_BIT	2

#define PTRACE_CFI_SS_EN_BIT	3

#define PTRACE_CFI_SS_LOCK_BIT	4

#define PTRACE_CFI_SS_PTR_BIT	5



#define PTRACE_CFI_LP_EN_STATE		_BITUL(PTRACE_CFI_LP_EN_BIT)

#define PTRACE_CFI_LP_LOCK_STATE	_BITUL(PTRACE_CFI_LP_LOCK_BIT)

#define PTRACE_CFI_ELP_STATE		_BITUL(PTRACE_CFI_ELP_BIT)

#define PTRACE_CFI_BRANCH_LANDING_PAD_EN_STATE		_BITUL(PTRACE_CFI_BRANCH_LANDING_PAD_EN_BIT)

#define PTRACE_CFI_BRANCH_LANDING_PAD_LOCK_STATE	\

	_BITUL(PTRACE_CFI_BRANCH_LANDING_PAD_LOCK_BIT)

#define PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_STATE	\

	_BITUL(PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_BIT)

#define PTRACE_CFI_SS_EN_STATE		_BITUL(PTRACE_CFI_SS_EN_BIT)

#define PTRACE_CFI_SS_LOCK_STATE	_BITUL(PTRACE_CFI_SS_LOCK_BIT)

#define PTRACE_CFI_SS_PTR_STATE		_BITUL(PTRACE_CFI_SS_PTR_BIT)



#define PTRACE_CFI_STATE_INVALID_MASK	~(PTRACE_CFI_LP_EN_STATE | \

					  PTRACE_CFI_LP_LOCK_STATE | \

					  PTRACE_CFI_ELP_STATE | \

#define PTRACE_CFI_STATE_INVALID_MASK	~(PTRACE_CFI_BRANCH_LANDING_PAD_EN_STATE | \

					  PTRACE_CFI_BRANCH_LANDING_PAD_LOCK_STATE | \

					  PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_STATE | \

					  PTRACE_CFI_SS_EN_STATE | \

					  PTRACE_CFI_SS_LOCK_STATE | \

					  PTRACE_CFI_SS_PTR_STATE)

arch/riscv/kernel/ptrace.c

+5 −5
Original line number Diff line number Diff line
@@ -303,11 +303,11 @@ static int riscv_cfi_get(struct task_struct *target, 
	regs = task_pt_regs(target);



	if (is_indir_lp_enabled(target)) {

		user_cfi.cfi_status.cfi_state |= PTRACE_CFI_LP_EN_STATE;

		user_cfi.cfi_status.cfi_state |= PTRACE_CFI_BRANCH_LANDING_PAD_EN_STATE;

		user_cfi.cfi_status.cfi_state |= is_indir_lp_locked(target) ?

						 PTRACE_CFI_LP_LOCK_STATE : 0;

						 PTRACE_CFI_BRANCH_LANDING_PAD_LOCK_STATE : 0;

		user_cfi.cfi_status.cfi_state |= (regs->status & SR_ELP) ?

						PTRACE_CFI_ELP_STATE : 0;

						PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_STATE : 0;

	}



	if (is_shstk_enabled(target)) {
@@ -349,7 +349,7 @@ static int riscv_cfi_set(struct task_struct *target, 
	 * rsvd field should be set to zero so that if those fields are needed in future

	 */

	if ((user_cfi.cfi_status.cfi_state &

	     (PTRACE_CFI_LP_EN_STATE | PTRACE_CFI_LP_LOCK_STATE |

	     (PTRACE_CFI_BRANCH_LANDING_PAD_EN_STATE | PTRACE_CFI_BRANCH_LANDING_PAD_LOCK_STATE |

	      PTRACE_CFI_SS_EN_STATE | PTRACE_CFI_SS_LOCK_STATE)) ||

	     (user_cfi.cfi_status.cfi_state & PTRACE_CFI_STATE_INVALID_MASK))

		return -EINVAL;
@@ -357,7 +357,7 @@ static int riscv_cfi_set(struct task_struct *target, 
	/* If lpad is enabled on target and ptrace requests to set / clear elp, do that */

	if (is_indir_lp_enabled(target)) {

		if (user_cfi.cfi_status.cfi_state &

		    PTRACE_CFI_ELP_STATE) /* set elp state */

		    PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_STATE) /* set elp state */

			regs->status |= SR_ELP;

		else

			regs->status &= ~SR_ELP; /* clear elp state */

tools/testing/selftests/riscv/cfi/cfitests.c

+3 −2
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ bool cfi_ptrace_test(void) 
		}



		switch (ptrace_test_num) {

#define CFI_ENABLE_MASK (PTRACE_CFI_LP_EN_STATE |	\

#define CFI_ENABLE_MASK (PTRACE_CFI_BRANCH_LANDING_PAD_EN_STATE |	\

			 PTRACE_CFI_SS_EN_STATE |	\

			 PTRACE_CFI_SS_PTR_STATE)

		case 0:
@@ -106,7 +106,8 @@ bool cfi_ptrace_test(void) 
						   __func__);

			break;

		case 1:

			if (!(cfi_reg.cfi_status.cfi_state & PTRACE_CFI_ELP_STATE))

			if (!(cfi_reg.cfi_status.cfi_state &

			      PTRACE_CFI_BRANCH_EXPECTED_LANDING_PAD_STATE))

				ksft_exit_fail_msg("%s: elp must have been set\n", __func__);

			/* clear elp state. not interested in anything else */

			cfi_reg.cfi_status.cfi_state = 0;