From 4965ac059da1ff7f3dac8f9556dd82c619063105 Mon Sep 17 00:00:00 2001 From: John Baldwin Date: Thu, 10 Mar 2022 15:40:44 -0800 Subject: [PATCH] gcore: Use PT_GETREGSET to fetch NT_PRSTATUS and NT_FPREGSET. Add a elf_putregnote() helper to build the ELF note for a register set. Once nice result of this approach is that this reuses the kernel's support for generating 32-bit register sets for 32-bit processes avoiding the need to duplicate that logic in elf32core.c. Reviewed by: markj Sponsored by: University of Cambridge, Google, Inc. Differential Revision: https://reviews.freebsd.org/D34447 --- usr.bin/gcore/elf32core.c | 59 -------------------------- usr.bin/gcore/elfcore.c | 87 +++++++++++++++++---------------------- 2 files changed, 37 insertions(+), 109 deletions(-) diff --git a/usr.bin/gcore/elf32core.c b/usr.bin/gcore/elf32core.c index 4e91fb0bc065..98e2408c4aa9 100644 --- a/usr.bin/gcore/elf32core.c +++ b/usr.bin/gcore/elf32core.c @@ -12,65 +12,6 @@ #define ELFCORE_COMPAT_32 1 #include "elfcore.c" -static void -elf_convert_gregset(elfcore_gregset_t *rd, struct reg *rs) -{ -#ifdef __amd64__ - rd->r_gs = rs->r_gs; - rd->r_fs = rs->r_fs; - rd->r_es = rs->r_es; - rd->r_ds = rs->r_ds; - rd->r_edi = rs->r_rdi; - rd->r_esi = rs->r_rsi; - rd->r_ebp = rs->r_rbp; - rd->r_ebx = rs->r_rbx; - rd->r_edx = rs->r_rdx; - rd->r_ecx = rs->r_rcx; - rd->r_eax = rs->r_rax; - rd->r_eip = rs->r_rip; - rd->r_cs = rs->r_cs; - rd->r_eflags = rs->r_rflags; - rd->r_esp = rs->r_rsp; - rd->r_ss = rs->r_ss; -#elif defined(__aarch64__) - int i; - - for (i = 0; i < 13; i++) - rd->r[i] = rs->x[i]; - rd->r_sp = rs->x[13]; - rd->r_lr = rs->x[14]; - rd->r_pc = rs->elr; - rd->r_cpsr = rs->spsr; -#elif defined(__powerpc64__) - int i; - - for (i = 0; i < 32; i++) - rd->fixreg[i] = rs->fixreg[i]; - rd->lr = rs->lr; - rd->cr = rs->cr; - rd->xer = rs->xer; - rd->ctr = rs->ctr; - rd->pc = rs->pc; -#else -#error Unsupported architecture -#endif -} - -static void -elf_convert_fpregset(elfcore_fpregset_t *rd, struct fpreg *rs) -{ -#ifdef __amd64__ - /* XXX this is wrong... */ - memcpy(rd, rs, sizeof(*rd)); -#elif defined(__aarch64__) - /* ARM64TODO */ -#elif defined(__powerpc64__) - memcpy(rd, rs, sizeof(*rd)); -#else -#error Unsupported architecture -#endif -} - static void elf_convert_siginfo(struct siginfo32 *sid, siginfo_t *sis) { diff --git a/usr.bin/gcore/elfcore.c b/usr.bin/gcore/elfcore.c index 9c5be76cfd7c..b93ef7ed92d6 100644 --- a/usr.bin/gcore/elfcore.c +++ b/usr.bin/gcore/elfcore.c @@ -89,8 +89,6 @@ typedef struct reg32 elfcore_gregset_t; typedef struct prpsinfo32 elfcore_prpsinfo_t; typedef struct prstatus32 elfcore_prstatus_t; typedef struct ptrace_lwpinfo32 elfcore_lwpinfo_t; -static void elf_convert_gregset(elfcore_gregset_t *rd, struct reg *rs); -static void elf_convert_fpregset(elfcore_fpregset_t *rd, struct fpreg *rs); static void elf_convert_lwpinfo(struct ptrace_lwpinfo32 *pld, struct ptrace_lwpinfo *pls); #else @@ -99,8 +97,6 @@ typedef gregset_t elfcore_gregset_t; typedef prpsinfo_t elfcore_prpsinfo_t; typedef prstatus_t elfcore_prstatus_t; typedef struct ptrace_lwpinfo elfcore_lwpinfo_t; -#define elf_convert_gregset(d,s) *d = *s -#define elf_convert_fpregset(d,s) *d = *s #define elf_convert_lwpinfo(d,s) *d = *s #endif @@ -111,9 +107,7 @@ static void cb_size_segment(struct map_entry *, void *); static void each_dumpable_segment(struct map_entry *, segment_callback, void *closure); static void elf_detach(void); /* atexit() handler. */ -static void *elf_note_fpregset(void *, size_t *); static void *elf_note_prpsinfo(void *, size_t *); -static void *elf_note_prstatus(void *, size_t *); static void *elf_note_thrmisc(void *, size_t *); static void *elf_note_ptlwpinfo(void *, size_t *); #if defined(__arm__) @@ -139,6 +133,7 @@ static void elf_puthdr(int, pid_t, struct map_entry *, void *, size_t, size_t, size_t, int); static void elf_putnote(int, notefunc_t, void *, struct sbuf *); static void elf_putnotes(pid_t, struct sbuf *, size_t *); +static void elf_putregnote(int, lwpid_t, struct sbuf *); static void freemap(struct map_entry *); static struct map_entry *readmap(pid_t); static void *procstat_sysctl(void *, int, size_t, size_t *sizep); @@ -376,8 +371,8 @@ elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep) elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb); for (i = 0; i < threads; ++i) { - elf_putnote(NT_PRSTATUS, elf_note_prstatus, tids + i, sb); - elf_putnote(NT_FPREGSET, elf_note_fpregset, tids + i, sb); + elf_putregnote(NT_PRSTATUS, tids[i], sb); + elf_putregnote(NT_FPREGSET, tids[i], sb); elf_putnote(NT_THRMISC, elf_note_thrmisc, tids + i, sb); elf_putnote(NT_PTLWPINFO, elf_note_ptlwpinfo, tids + i, sb); #if defined(__arm__) @@ -414,6 +409,40 @@ elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep) *sizep = size; } +/* + * Emit one register set note section to sbuf. + */ +static void +elf_putregnote(int type, lwpid_t tid, struct sbuf *sb) +{ + Elf_Note note; + struct iovec iov; + ssize_t old_len; + + iov.iov_base = NULL; + iov.iov_len = 0; + if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0) + return; + iov.iov_base = calloc(1, iov.iov_len); + if (iov.iov_base == NULL) + errx(1, "out of memory"); + if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0) + errx(1, "failed to fetch register set %d", type); + + note.n_namesz = 8; /* strlen("FreeBSD") + 1 */ + note.n_descsz = iov.iov_len; + note.n_type = type; + + sbuf_bcat(sb, ¬e, sizeof(note)); + sbuf_start_section(sb, &old_len); + sbuf_bcat(sb, "FreeBSD", note.n_namesz); + sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0); + sbuf_start_section(sb, &old_len); + sbuf_bcat(sb, iov.iov_base, iov.iov_len); + sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0); + free(iov.iov_base); +} + /* * Emit one note section to sbuf. */ @@ -654,48 +683,6 @@ elf_note_prpsinfo(void *arg, size_t *sizep) return (psinfo); } -static void * -elf_note_prstatus(void *arg, size_t *sizep) -{ - lwpid_t tid; - elfcore_prstatus_t *status; - struct reg greg; - - tid = *(lwpid_t *)arg; - status = calloc(1, sizeof(*status)); - if (status == NULL) - errx(1, "out of memory"); - status->pr_version = PRSTATUS_VERSION; - status->pr_statussz = sizeof(*status); - status->pr_gregsetsz = sizeof(elfcore_gregset_t); - status->pr_fpregsetsz = sizeof(elfcore_fpregset_t); - status->pr_osreldate = __FreeBSD_version; - status->pr_pid = tid; - ptrace(PT_GETREGS, tid, (void *)&greg, 0); - elf_convert_gregset(&status->pr_reg, &greg); - - *sizep = sizeof(*status); - return (status); -} - -static void * -elf_note_fpregset(void *arg, size_t *sizep) -{ - lwpid_t tid; - elfcore_fpregset_t *fpregset; - fpregset_t fpreg; - - tid = *(lwpid_t *)arg; - fpregset = calloc(1, sizeof(*fpregset)); - if (fpregset == NULL) - errx(1, "out of memory"); - ptrace(PT_GETFPREGS, tid, (void *)&fpreg, 0); - elf_convert_fpregset(fpregset, &fpreg); - - *sizep = sizeof(*fpregset); - return (fpregset); -} - static void * elf_note_thrmisc(void *arg, size_t *sizep) {