From: Alan Hayward Date: Fri, 22 Mar 2019 10:31:02 +0000 (+0000) Subject: AArch64: Read pauth registers X-Git-Tag: binutils-2_33~1768 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=76bed0fd9493868889929ca9dcd32350c1d864be;p=external%2Fbinutils.git AArch64: Read pauth registers Initialise the pauth registers when creating a target description, and store the regnum of the first pauth register. Use ptrace to read the registers in the pauth feature. Do not allow the registers to be written. gdb/ChangeLog: * aarch64-linux-nat.c (fetch_pauth_masks_from_thread): New function. (aarch64_linux_nat_target::fetch_registers): Read pauth registers. * aarch64-tdep.c (aarch64_cannot_store_register): New function. (aarch64_gdbarch_init): Add puth registers. * aarch64-tdep.h (struct gdbarch_tdep): Add pauth features. * arch/aarch64.h (AARCH64_PAUTH_DMASK_REGNUM): New define. (AARCH64_PAUTH_CMASK_REGNUM): Likewise. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index bd09e4f..78ec704 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,6 +1,18 @@ 2019-03-22 Alan Hayward Jiong Wang + * aarch64-linux-nat.c (fetch_pauth_masks_from_thread): New + function. + (aarch64_linux_nat_target::fetch_registers): Read pauth registers. + * aarch64-tdep.c (aarch64_cannot_store_register): New function. + (aarch64_gdbarch_init): Add puth registers. + * aarch64-tdep.h (struct gdbarch_tdep): Add pauth features. + * arch/aarch64.h (AARCH64_PAUTH_DMASK_REGNUM): New define. + (AARCH64_PAUTH_CMASK_REGNUM): Likewise. + +2019-03-22 Alan Hayward + Jiong Wang + * aarch64-linux-nat.c (aarch64_linux_nat_target::read_description): Read PACA hwcap. * aarch64-linux-tdep.c diff --git a/gdb/aarch64-linux-nat.c b/gdb/aarch64-linux-nat.c index 9572055..86c7e87 100644 --- a/gdb/aarch64-linux-nat.c +++ b/gdb/aarch64-linux-nat.c @@ -423,6 +423,31 @@ store_sveregs_to_thread (struct regcache *regcache) perror_with_name (_("Unable to store sve registers")); } +/* Fill GDB's register array with the pointer authentication mask values from + the current thread. */ + +static void +fetch_pauth_masks_from_thread (struct regcache *regcache) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (regcache->arch ()); + int ret; + struct iovec iovec; + uint64_t pauth_regset[2] = {0, 0}; + int tid = regcache->ptid ().lwp (); + + iovec.iov_base = &pauth_regset; + iovec.iov_len = sizeof (pauth_regset); + + ret = ptrace (PTRACE_GETREGSET, tid, NT_ARM_PAC_MASK, &iovec); + if (ret != 0) + perror_with_name (_("unable to fetch pauth registers.")); + + regcache->raw_supply (AARCH64_PAUTH_DMASK_REGNUM (tdep->pauth_reg_base), + &pauth_regset[0]); + regcache->raw_supply (AARCH64_PAUTH_CMASK_REGNUM (tdep->pauth_reg_base), + &pauth_regset[1]); +} + /* Implement the "fetch_registers" target_ops method. */ void @@ -438,6 +463,9 @@ aarch64_linux_nat_target::fetch_registers (struct regcache *regcache, fetch_sveregs_from_thread (regcache); else fetch_fpregs_from_thread (regcache); + + if (tdep->has_pauth ()) + fetch_pauth_masks_from_thread (regcache); } else if (regno < AARCH64_V0_REGNUM) fetch_gregs_from_thread (regcache); @@ -445,6 +473,13 @@ aarch64_linux_nat_target::fetch_registers (struct regcache *regcache, fetch_sveregs_from_thread (regcache); else fetch_fpregs_from_thread (regcache); + + if (tdep->has_pauth ()) + { + if (regno == AARCH64_PAUTH_DMASK_REGNUM (tdep->pauth_reg_base) + || regno == AARCH64_PAUTH_CMASK_REGNUM (tdep->pauth_reg_base)) + fetch_pauth_masks_from_thread (regcache); + } } /* Implement the "store_registers" target_ops method. */ diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index 0518837..66fdd7b 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -175,6 +175,14 @@ static const char *const aarch64_sve_register_names[] = "ffr", "vg" }; +static const char *const aarch64_pauth_register_names[] = +{ + /* Authentication mask for data pointer. */ + "pauth_dmask", + /* Authentication mask for code pointer. */ + "pauth_cmask" +}; + /* AArch64 prologue cache structure. */ struct aarch64_prologue_cache { @@ -2936,6 +2944,21 @@ aarch64_add_reggroups (struct gdbarch *gdbarch) reggroup_add (gdbarch, restore_reggroup); } +/* Implement the "cannot_store_register" gdbarch method. */ + +static int +aarch64_cannot_store_register (struct gdbarch *gdbarch, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (!tdep->has_pauth ()) + return 0; + + /* Pointer authentication registers are read-only. */ + return (regnum == AARCH64_PAUTH_DMASK_REGNUM (tdep->pauth_reg_base) + || regnum == AARCH64_PAUTH_CMASK_REGNUM (tdep->pauth_reg_base)); +} + /* Initialize the current architecture based on INFO. If possible, re-use an architecture from ARCHES, which is a list of architectures already created during this debugging session. @@ -2956,8 +2979,10 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) const struct tdesc_feature *feature_core; const struct tdesc_feature *feature_fpu; const struct tdesc_feature *feature_sve; + const struct tdesc_feature *feature_pauth; int num_regs = 0; int num_pseudo_regs = 0; + int first_pauth_regnum = -1; /* Ensure we always have a target description. */ if (!tdesc_has_registers (tdesc)) @@ -2967,6 +2992,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) feature_core = tdesc_find_feature (tdesc, "org.gnu.gdb.aarch64.core"); feature_fpu = tdesc_find_feature (tdesc, "org.gnu.gdb.aarch64.fpu"); feature_sve = tdesc_find_feature (tdesc, "org.gnu.gdb.aarch64.sve"); + feature_pauth = tdesc_find_feature (tdesc, "org.gnu.gdb.aarch64.pauth"); if (feature_core == NULL) return NULL; @@ -3021,6 +3047,21 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) num_pseudo_regs += 32; /* add the Bn scalar register pseudos */ } + /* Add the pauth registers. */ + if (feature_pauth != NULL) + { + first_pauth_regnum = num_regs; + + /* Validate the descriptor provides the mandatory PAUTH registers and + allocate their numbers. */ + for (i = 0; i < ARRAY_SIZE (aarch64_pauth_register_names); i++) + valid_p &= tdesc_numbered_register (feature_pauth, tdesc_data, + first_pauth_regnum + i, + aarch64_pauth_register_names[i]); + + num_regs += i; + } + if (!valid_p) { tdesc_data_cleanup (tdesc_data); @@ -3054,6 +3095,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) tdep->jb_pc = -1; /* Longjump support not enabled by default. */ tdep->jb_elt_size = 8; tdep->vq = aarch64_get_tdesc_vq (tdesc); + tdep->pauth_reg_base = first_pauth_regnum; set_gdbarch_push_dummy_call (gdbarch, aarch64_push_dummy_call); set_gdbarch_frame_align (gdbarch, aarch64_frame_align); @@ -3084,6 +3126,7 @@ aarch64_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) set_tdesc_pseudo_register_type (gdbarch, aarch64_pseudo_register_type); set_tdesc_pseudo_register_reggroup_p (gdbarch, aarch64_pseudo_register_reggroup_p); + set_gdbarch_cannot_store_register (gdbarch, aarch64_cannot_store_register); /* ABI */ set_gdbarch_short_bit (gdbarch, 16); diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index 3db6bee..f9fc896 100644 --- a/gdb/aarch64-tdep.h +++ b/gdb/aarch64-tdep.h @@ -87,6 +87,14 @@ struct gdbarch_tdep { return vq != 0; } + + int pauth_reg_base; + + /* Returns true if the target supports pauth. */ + bool has_pauth () const + { + return pauth_reg_base != -1; + } }; const target_desc *aarch64_read_description (uint64_t vq, bool pauth_p); diff --git a/gdb/arch/aarch64.h b/gdb/arch/aarch64.h index 4fe6d02..8c80b7b 100644 --- a/gdb/arch/aarch64.h +++ b/gdb/arch/aarch64.h @@ -66,6 +66,9 @@ enum aarch64_regnum #define AARCH64_B0_REGNUM (AARCH64_H0_REGNUM + 32) #define AARCH64_SVE_V0_REGNUM (AARCH64_B0_REGNUM + 32) +#define AARCH64_PAUTH_DMASK_REGNUM(pauth_reg_base) (pauth_reg_base) +#define AARCH64_PAUTH_CMASK_REGNUM(pauth_reg_base) (pauth_reg_base + 1) + #define AARCH64_X_REGS_NUM 31 #define AARCH64_V_REGS_NUM 32 #define AARCH64_SVE_Z_REGS_NUM AARCH64_V_REGS_NUM