git: 4965ac059da1 - main - gcore: Use PT_GETREGSET to fetch NT_PRSTATUS and NT_FPREGSET.
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Date: Thu, 10 Mar 2022 23:41:35 UTC
The branch main has been updated by jhb:
URL: https://cgit.FreeBSD.org/src/commit/?id=4965ac059da1ff7f3dac8f9556dd82c619063105
commit 4965ac059da1ff7f3dac8f9556dd82c619063105
Author: John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2022-03-10 23:40:44 +0000
Commit: John Baldwin <jhb@FreeBSD.org>
CommitDate: 2022-03-10 23:40:44 +0000
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)
{