From dd6876c91cd40cc105b1a91f418ca2c80683b314 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Tue, 12 Mar 2019 13:39:02 -0700 Subject: [PATCH] Support fs_base and gs_base on FreeBSD/i386. The i386 BSD native target uses the same ptrace operations (PT_[GS]ET[FG]SBASE) as the amd64 BSD native target to fetch and store the registers. The amd64 BSD native now uses 'tdep->fsbase_regnum' instead of hardcoding AMD64_FSBASE_REGNUM and AMD64_GSBASE_REGNUM to support 32-bit targets. In addition, the store operations explicitly zero the new register value before fetching it from the register cache to ensure 32-bit values are zero-extended. gdb/ChangeLog: * amd64-bsd-nat.c (amd64bsd_fetch_inferior_registers): Use tdep->fsbase_regnum instead of constants for fs_base and gs_base. (amd64bsd_store_inferior_registers): Likewise. * amd64-fbsd-nat.c (amd64_fbsd_nat_target::read_description): Enable segment base registers. * i386-bsd-nat.c (i386bsd_fetch_inferior_registers): Use PT_GETFSBASE and PT_GETGSBASE. (i386bsd_store_inferior_registers): Use PT_SETFSBASE and PT_SETGSBASE. * i386-fbsd-nat.c (i386_fbsd_nat_target::read_description): Enable segment base registers. * i386-fbsd-tdep.c (i386fbsd_core_read_description): Likewise. --- gdb/ChangeLog | 15 +++++++++++++++ gdb/amd64-bsd-nat.c | 26 +++++++++++++++++-------- gdb/amd64-fbsd-nat.c | 4 ++-- gdb/i386-bsd-nat.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++ gdb/i386-fbsd-nat.c | 2 +- gdb/i386-fbsd-tdep.c | 2 +- 6 files changed, 91 insertions(+), 12 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 79ba941..c91e975 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,20 @@ 2019-03-12 John Baldwin + * amd64-bsd-nat.c (amd64bsd_fetch_inferior_registers): Use + tdep->fsbase_regnum instead of constants for fs_base and gs_base. + (amd64bsd_store_inferior_registers): Likewise. + * amd64-fbsd-nat.c (amd64_fbsd_nat_target::read_description): + Enable segment base registers. + * i386-bsd-nat.c (i386bsd_fetch_inferior_registers): Use + PT_GETFSBASE and PT_GETGSBASE. + (i386bsd_store_inferior_registers): Use PT_SETFSBASE and + PT_SETGSBASE. + * i386-fbsd-nat.c (i386_fbsd_nat_target::read_description): Enable + segment base registers. + * i386-fbsd-tdep.c (i386fbsd_core_read_description): Likewise. + +2019-03-12 John Baldwin + * amd64-fbsd-nat.c (amd64_fbsd_nat_target::read_description): Update calls to i386_target_description to add 'segments' parameter. diff --git a/gdb/amd64-bsd-nat.c b/gdb/amd64-bsd-nat.c index a2a91ab..35763a5 100644 --- a/gdb/amd64-bsd-nat.c +++ b/gdb/amd64-bsd-nat.c @@ -43,6 +43,9 @@ amd64bsd_fetch_inferior_registers (struct regcache *regcache, int regnum) { struct gdbarch *gdbarch = regcache->arch (); pid_t pid = get_ptrace_pid (regcache->ptid ()); +#if defined(PT_GETFSBASE) || defined(PT_GETGSBASE) + const struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); +#endif if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, regnum)) { @@ -57,27 +60,27 @@ amd64bsd_fetch_inferior_registers (struct regcache *regcache, int regnum) } #ifdef PT_GETFSBASE - if (regnum == -1 || regnum == AMD64_FSBASE_REGNUM) + if (regnum == -1 || regnum == tdep->fsbase_regnum) { register_t base; if (ptrace (PT_GETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) perror_with_name (_("Couldn't get segment register fs_base")); - regcache->raw_supply (AMD64_FSBASE_REGNUM, &base); + regcache->raw_supply (tdep->fsbase_regnum, &base); if (regnum != -1) return; } #endif #ifdef PT_GETGSBASE - if (regnum == -1 || regnum == AMD64_GSBASE_REGNUM) + if (regnum == -1 || regnum == tdep->fsbase_regnum + 1) { register_t base; if (ptrace (PT_GETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) perror_with_name (_("Couldn't get segment register gs_base")); - regcache->raw_supply (AMD64_GSBASE_REGNUM, &base); + regcache->raw_supply (tdep->fsbase_regnum + 1, &base); if (regnum != -1) return; } @@ -116,6 +119,9 @@ amd64bsd_store_inferior_registers (struct regcache *regcache, int regnum) { struct gdbarch *gdbarch = regcache->arch (); pid_t pid = get_ptrace_pid (regcache->ptid ()); +#if defined(PT_SETFSBASE) || defined(PT_SETGSBASE) + const struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); +#endif if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, regnum)) { @@ -134,11 +140,13 @@ amd64bsd_store_inferior_registers (struct regcache *regcache, int regnum) } #ifdef PT_SETFSBASE - if (regnum == -1 || regnum == AMD64_FSBASE_REGNUM) + if (regnum == -1 || regnum == tdep->fsbase_regnum) { register_t base; - regcache->raw_collect (AMD64_FSBASE_REGNUM, &base); + /* Clear the full base value to support 32-bit targets. */ + base = 0; + regcache->raw_collect (tdep->fsbase_regnum, &base); if (ptrace (PT_SETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) perror_with_name (_("Couldn't write segment register fs_base")); @@ -147,11 +155,13 @@ amd64bsd_store_inferior_registers (struct regcache *regcache, int regnum) } #endif #ifdef PT_SETGSBASE - if (regnum == -1 || regnum == AMD64_GSBASE_REGNUM) + if (regnum == -1 || regnum == tdep->fsbase_regnum + 1) { register_t base; - regcache->raw_collect (AMD64_GSBASE_REGNUM, &base); + /* Clear the full base value to support 32-bit targets. */ + base = 0; + regcache->raw_collect (tdep->fsbase_regnum + 1, &base); if (ptrace (PT_SETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) perror_with_name (_("Couldn't write segment register gs_base")); diff --git a/gdb/amd64-fbsd-nat.c b/gdb/amd64-fbsd-nat.c index 9fff763..cc676d3 100644 --- a/gdb/amd64-fbsd-nat.c +++ b/gdb/amd64-fbsd-nat.c @@ -190,13 +190,13 @@ amd64_fbsd_nat_target::read_description () if (is64) return amd64_target_description (xcr0, true); else - return i386_target_description (xcr0, false); + return i386_target_description (xcr0, true); } #endif if (is64) return amd64_target_description (X86_XSTATE_SSE_MASK, true); else - return i386_target_description (X86_XSTATE_SSE_MASK, false); + return i386_target_description (X86_XSTATE_SSE_MASK, true); } #if defined(HAVE_PT_GETDBREGS) && defined(USE_SIGTRAP_SIGINFO) diff --git a/gdb/i386-bsd-nat.c b/gdb/i386-bsd-nat.c index 009a8dc..a10b496 100644 --- a/gdb/i386-bsd-nat.c +++ b/gdb/i386-bsd-nat.c @@ -144,6 +144,33 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum) return; } +#ifdef PT_GETFSBASE + if (regnum == -1 || regnum == I386_FSBASE_REGNUM) + { + register_t base; + + if (ptrace (PT_GETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) + perror_with_name (_("Couldn't get segment register fs_base")); + + regcache->raw_supply (I386_FSBASE_REGNUM, &base); + if (regnum != -1) + return; + } +#endif +#ifdef PT_GETGSBASE + if (regnum == -1 || regnum == I386_GSBASE_REGNUM) + { + register_t base; + + if (ptrace (PT_GETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) + perror_with_name (_("Couldn't get segment register gs_base")); + + regcache->raw_supply (I386_GSBASE_REGNUM, &base); + if (regnum != -1) + return; + } +#endif + if (regnum == -1 || regnum >= I386_ST0_REGNUM) { struct fpreg fpregs; @@ -211,6 +238,33 @@ i386bsd_store_inferior_registers (struct regcache *regcache, int regnum) return; } +#ifdef PT_SETFSBASE + if (regnum == -1 || regnum == I386_FSBASE_REGNUM) + { + register_t base; + + regcache->raw_collect (I386_FSBASE_REGNUM, &base); + + if (ptrace (PT_SETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) + perror_with_name (_("Couldn't write segment register fs_base")); + if (regnum != -1) + return; + } +#endif +#ifdef PT_SETGSBASE + if (regnum == -1 || regnum == I386_GSBASE_REGNUM) + { + register_t base; + + regcache->raw_collect (I386_GSBASE_REGNUM, &base); + + if (ptrace (PT_SETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1) + perror_with_name (_("Couldn't write segment register gs_base")); + if (regnum != -1) + return; + } +#endif + if (regnum == -1 || regnum >= I386_ST0_REGNUM) { struct fpreg fpregs; diff --git a/gdb/i386-fbsd-nat.c b/gdb/i386-fbsd-nat.c index 7106e90..be5d4c6 100644 --- a/gdb/i386-fbsd-nat.c +++ b/gdb/i386-fbsd-nat.c @@ -160,7 +160,7 @@ i386_fbsd_nat_target::read_description () if (x86bsd_xsave_len == 0) xcr0 = X86_XSTATE_SSE_MASK; - return i386_target_description (xcr0, false); + return i386_target_description (xcr0, true); } #endif diff --git a/gdb/i386-fbsd-tdep.c b/gdb/i386-fbsd-tdep.c index 2f28bad..ac57e73 100644 --- a/gdb/i386-fbsd-tdep.c +++ b/gdb/i386-fbsd-tdep.c @@ -267,7 +267,7 @@ i386fbsd_core_read_description (struct gdbarch *gdbarch, struct target_ops *target, bfd *abfd) { - return i386_target_description (i386fbsd_core_read_xcr0 (abfd), false); + return i386_target_description (i386fbsd_core_read_xcr0 (abfd), true); } /* Similar to i386_supply_fpregset, but use XSAVE extended state. */ -- 2.7.4