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gdb: SPARC ADI support

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The M7 processor supports an Application Data Integrity (ADI) feature
that detects invalid data accesses.  When software allocates data, it
chooses a 4-bit version number, sets the version in the upper 4 bits
of the 64-bit pointer to that data, and stores the 4-bit version in
every cacheline of the object.  Hardware saves the latter in spare
bits in the cache and memory hierarchy. On each load and store, the
processor compares the upper 4 VA (virtual address) bits to the
cacheline's version. If there is a mismatch, the processor generates a
version mismatch trap which can be either precise or disrupting.  The
trap is an error condition which the kernel delivers to the process as
a SIGSEGV signal.

The upper 4 bits of the VA represent a version and are not part of the
true address.  The processor clears these bits and sign extends bit 59
to generate the true address.

Note that 32-bit applications cannot use ADI.

This patch adds ADI support in gdb which allows the user to examine
current version tags and assign new version tags in the program.  It
also catches and reports precise or disrupting memory corruption
traps.

gdb/ChangeLog:
2017-08-07  Weimin Pan  <weimin.pan@oracle.com>

	* sparc64-tdep.h: (adi_normalize_address): New export.
	* sparc-nat.h: (open_adi_tag_fd): New export.
	* sparc64-linux-nat.c: (open_adi_tag_fd): New function.
	* sparc64-linux-tdep.c:
	(SEGV_ACCADI, SEGV_ADIDERR, SEGV_ADIPERR) New defines.
	(sparc64_linux_handle_segmentation_fault): New function.
	(sparc64_linux_init_abi): Register
	sparc64_linux_handle_segmentation_fault
	* sparc64-tdep.c: Include cli-utils.h,gdbcmd.h,auxv.h.
	(sparc64_addr_bits_remove): New function.
	(sparc64_init_abi): Register sparc64_addr_bits_remove.
	(MAX_PROC_NAME_SIZE): New macro.
	(AT_ADI_BLKSZ, AT_ADI_NBITS, AT_ADI_UEONADI) New defines.
	(sparc64adilist): New variable.
	(adi_proc_list): New variable.
	(find_adi_info): New function.
	(add_adi_info): New function.
	(get_adi_info_proc): New function.
	(get_adi_info): New function.
	(info_adi_command): New function.
	(read_maps_entry): New function.
	(adi_available): New function.
	(adi_normalize_address): New function.
	(adi_align_address): New function.
	(adi_convert_byte_count): New function.
	(adi_tag_fd): New function.
	(adi_is_addr_mapped): New function.
	(adi_read_versions): New function.
	(adi_write_versions): New function.
	(adi_print_versions): New function.
	(do_examine): New function.
	(do_assign): New function.
	(adi_examine_command): New function.
	(adi_assign_command): New function.
	(_initialize_sparc64_adi_tdep): New function.

gdb/doc/ChangeLog:
2017-08-07  Weimin Pan  <weimin.pan@oracle.com>

	* gdb.texinfo (Architectures): Add new Sparc64 section to document
	ADI support.
	* NEWS: Add "adi examine" and "adi assign" commands.

gdb/testsuite/ChangeLog:
2017-08-07  Weimin Pan  <weimin.pan@oracle.com>

	* gdb.arch/sparc64-adi.exp: New file.
	* gdb.arch/sparc64-adi.c: New file.
This commit is contained in:
Weimin Pan
2017-08-23 10:57:37 +02:00
committed by Jose E. Marchesi
parent 98973784dc
commit 58afddc6c7
10 changed files with 903 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

509
gdb/sparc64-tdep.c
View File

@ -46,6 +46,505 @@
sparc64_-prefix for 64-bit specific code and the sparc_-prefix for
code can handle both. */
/* The M7 processor supports an Application Data Integrity (ADI) feature
that detects invalid data accesses. When software allocates memory and
enables ADI on the allocated memory, it chooses a 4-bit version number,
sets the version in the upper 4 bits of the 64-bit pointer to that data,
and stores the 4-bit version in every cacheline of the object. Hardware
saves the latter in spare bits in the cache and memory hierarchy. On each
load and store, the processor compares the upper 4 VA (virtual address) bits
to the cacheline's version. If there is a mismatch, the processor generates
a version mismatch trap which can be either precise or disrupting.
The trap is an error condition which the kernel delivers to the process
as a SIGSEGV signal.
The upper 4 bits of the VA represent a version and are not part of the
true address. The processor clears these bits and sign extends bit 59
to generate the true address.
Note that 32-bit applications cannot use ADI. */
#include <algorithm>
#include "cli/cli-utils.h"
#include "gdbcmd.h"
#include "auxv.h"
#define MAX_PROC_NAME_SIZE sizeof("/proc/99999/lwp/9999/adi/lstatus")
/* ELF Auxiliary vectors */
#ifndef AT_ADI_BLKSZ
#define AT_ADI_BLKSZ 34
#endif
#ifndef AT_ADI_NBITS
#define AT_ADI_NBITS 35
#endif
#ifndef AT_ADI_UEONADI
#define AT_ADI_UEONADI 36
#endif
/* ADI command list. */
static struct cmd_list_element *sparc64adilist = NULL;
/* ADI stat settings. */
typedef struct
{
/* The ADI block size. */
unsigned long blksize;
/* Number of bits used for an ADI version tag which can be
* used together with the shift value for an ADI version tag
* to encode or extract the ADI version value in a pointer. */
unsigned long nbits;
/* The maximum ADI version tag value supported. */
int max_version;
/* ADI version tag file. */
int tag_fd = 0;
/* ADI availability check has been done. */
bool checked_avail = false;
/* ADI is available. */
bool is_avail = false;
} adi_stat_t;
/* Per-process ADI stat info. */
typedef struct sparc64_adi_info
{
sparc64_adi_info (pid_t pid_)
: pid (pid_)
{}
/* The process identifier. */
pid_t pid;
/* The ADI stat. */
adi_stat_t stat = {};
} sparc64_adi_info;
static std::forward_list<sparc64_adi_info> adi_proc_list;
/* Get ADI info for process PID, creating one if it doesn't exist. */
static sparc64_adi_info *
get_adi_info_proc (pid_t pid)
{
auto found = std::find_if (adi_proc_list.begin (), adi_proc_list.end (),
[&pid] (const sparc64_adi_info &info)
{
return info.pid == pid;
});
if (found == adi_proc_list.end ())
{
adi_proc_list.emplace_front (pid);
return &adi_proc_list.front ();
}
else
{
return &(*found);
}
}
static adi_stat_t
get_adi_info (pid_t pid)
{
sparc64_adi_info *proc;
proc = get_adi_info_proc (pid);
return proc->stat;
}
/* Is called when GDB is no longer debugging process PID. It
deletes data structure that keeps track of the ADI stat. */
void
sparc64_forget_process (pid_t pid)
{
int target_errno;
for (auto pit = adi_proc_list.before_begin (),
it = std::next (pit);
it != adi_proc_list.end ();
)
{
if ((*it).pid == pid)
{
if ((*it).stat.tag_fd > 0)
target_fileio_close ((*it).stat.tag_fd, &target_errno);
adi_proc_list.erase_after (pit);
break;
}
else
pit = it++;
}
}
static void
info_adi_command (char *args, int from_tty)
{
printf_unfiltered ("\"adi\" must be followed by \"examine\" "
"or \"assign\".\n");
help_list (sparc64adilist, "adi ", all_commands, gdb_stdout);
}
/* Read attributes of a maps entry in /proc/[pid]/adi/maps. */
static void
read_maps_entry (const char *line,
ULONGEST *addr, ULONGEST *endaddr)
{
const char *p = line;
*addr = strtoulst (p, &p, 16);
if (*p == '-')
p++;
*endaddr = strtoulst (p, &p, 16);
}
/* Check if ADI is available. */
static bool
adi_available (void)
{
pid_t pid = ptid_get_pid (inferior_ptid);
sparc64_adi_info *proc = get_adi_info_proc (pid);
if (proc->stat.checked_avail)
return proc->stat.is_avail;
proc->stat.checked_avail = true;
if (target_auxv_search (&current_target, AT_ADI_BLKSZ,
&proc->stat.blksize) <= 0)
return false;
target_auxv_search (&current_target, AT_ADI_NBITS, &proc->stat.nbits);
proc->stat.max_version = (1 << proc->stat.nbits) - 2;
proc->stat.is_avail = true;
return proc->stat.is_avail;
}
/* Normalize a versioned address - a VA with ADI bits (63-60) set. */
static CORE_ADDR
adi_normalize_address (CORE_ADDR addr)
{
adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid));
if (ast.nbits)
return ((CORE_ADDR)(((long)addr << ast.nbits) >> ast.nbits));
return addr;
}
/* Align a normalized address - a VA with bit 59 sign extended into
ADI bits. */
static CORE_ADDR
adi_align_address (CORE_ADDR naddr)
{
adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid));
return (naddr - (naddr % ast.blksize)) / ast.blksize;
}
/* Convert a byte count to count at a ratio of 1:adi_blksz. */
static int
adi_convert_byte_count (CORE_ADDR naddr, int nbytes, CORE_ADDR locl)
{
adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid));
return ((naddr + nbytes + ast.blksize - 1) / ast.blksize) - locl;
}
/* The /proc/[pid]/adi/tags file, which allows gdb to get/set ADI
version in a target process, maps linearly to the address space
of the target process at a ratio of 1:adi_blksz.
A read (or write) at offset K in the file returns (or modifies)
the ADI version tag stored in the cacheline containing address
K * adi_blksz, encoded as 1 version tag per byte. The allowed
version tag values are between 0 and adi_stat.max_version. */
static int
adi_tag_fd (void)
{
pid_t pid = ptid_get_pid (inferior_ptid);
sparc64_adi_info *proc = get_adi_info_proc (pid);
if (proc->stat.tag_fd != 0)
return proc->stat.tag_fd;
char cl_name[MAX_PROC_NAME_SIZE];
snprintf (cl_name, sizeof(cl_name), "/proc/%d/adi/tags", pid);
int target_errno;
proc->stat.tag_fd = target_fileio_open (NULL, cl_name, O_RDWR|O_EXCL,
0, &target_errno);
return proc->stat.tag_fd;
}
/* Check if an address set is ADI enabled, using /proc/[pid]/adi/maps
which was exported by the kernel and contains the currently ADI
mapped memory regions and their access permissions. */
static bool
adi_is_addr_mapped (CORE_ADDR vaddr, size_t cnt)
{
char filename[MAX_PROC_NAME_SIZE];
size_t i = 0;
pid_t pid = ptid_get_pid (inferior_ptid);
snprintf (filename, sizeof filename, "/proc/%d/adi/maps", pid);
char *data = target_fileio_read_stralloc (NULL, filename);
if (data)
{
struct cleanup *cleanup = make_cleanup (xfree, data);
adi_stat_t adi_stat = get_adi_info (pid);
char *line;
for (line = strtok (data, "\n"); line; line = strtok (NULL, "\n"))
{
ULONGEST addr, endaddr;
read_maps_entry (line, &addr, &endaddr);
while (((vaddr + i) * adi_stat.blksize) >= addr
&& ((vaddr + i) * adi_stat.blksize) < endaddr)
{
if (++i == cnt)
{
do_cleanups (cleanup);
return true;
}
}
}
do_cleanups (cleanup);
}
else
warning (_("unable to open /proc file '%s'"), filename);
return false;
}
/* Read ADI version tag value for memory locations starting at "VADDR"
for "SIZE" number of bytes. */
static int
adi_read_versions (CORE_ADDR vaddr, size_t size, unsigned char *tags)
{
int fd = adi_tag_fd ();
if (fd == -1)
return -1;
if (!adi_is_addr_mapped (vaddr, size))
{
adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid));
error(_("Address at 0x%lx is not in ADI maps"), vaddr*ast.blksize);
}
int target_errno;
return target_fileio_pread (fd, tags, size, vaddr, &target_errno);
}
/* Write ADI version tag for memory locations starting at "VADDR" for
"SIZE" number of bytes to "TAGS". */
static int
adi_write_versions (CORE_ADDR vaddr, size_t size, unsigned char *tags)
{
int fd = adi_tag_fd ();
if (fd == -1)
return -1;
if (!adi_is_addr_mapped (vaddr, size))
{
adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid));
error(_("Address at 0x%lx is not in ADI maps"), vaddr*ast.blksize);
}
int target_errno;
return target_fileio_pwrite (fd, tags, size, vaddr, &target_errno);
}
/* Print ADI version tag value in "TAGS" for memory locations starting
at "VADDR" with number of "CNT". */
static void
adi_print_versions (CORE_ADDR vaddr, size_t cnt, unsigned char *tags)
{
int v_idx = 0;
const int maxelts = 8; /* # of elements per line */
adi_stat_t adi_stat = get_adi_info (ptid_get_pid (inferior_ptid));
while (cnt > 0)
{
QUIT;
printf_filtered ("0x%016lx:\t", vaddr * adi_stat.blksize);
for (int i = maxelts; i > 0 && cnt > 0; i--, cnt--)
{
if (tags[v_idx] == 0xff) /* no version tag */
printf_filtered ("-");
else
printf_filtered ("%1X", tags[v_idx]);
if (cnt > 1)
printf_filtered (" ");
++v_idx;
}
printf_filtered ("\n");
gdb_flush (gdb_stdout);
vaddr += maxelts;
}
}
static void
do_examine (CORE_ADDR start, int bcnt)
{
CORE_ADDR vaddr = adi_normalize_address (start);
struct cleanup *cleanup;
CORE_ADDR vstart = adi_align_address (vaddr);
int cnt = adi_convert_byte_count (vaddr, bcnt, vstart);
unsigned char *buf = (unsigned char *) xmalloc (cnt);
cleanup = make_cleanup (xfree, buf);
int read_cnt = adi_read_versions (vstart, cnt, buf);
if (read_cnt == -1)
error (_("No ADI information"));
else if (read_cnt < cnt)
error(_("No ADI information at 0x%lx"), vaddr);
adi_print_versions (vstart, cnt, buf);
do_cleanups (cleanup);
}
static void
do_assign (CORE_ADDR start, size_t bcnt, int version)
{
CORE_ADDR vaddr = adi_normalize_address (start);
CORE_ADDR vstart = adi_align_address (vaddr);
int cnt = adi_convert_byte_count (vaddr, bcnt, vstart);
std::vector<unsigned char> buf (cnt, version);
int set_cnt = adi_write_versions (vstart, cnt, buf.data ());
if (set_cnt == -1)
error (_("No ADI information"));
else if (set_cnt < cnt)
error(_("No ADI information at 0x%lx"), vaddr);
}
/* ADI examine version tag command.
Command syntax:
adi (examine|x)/count <addr> */
static void
adi_examine_command (char *args, int from_tty)
{
/* make sure program is active and adi is available */
if (!target_has_execution)
error (_("ADI command requires a live process/thread"));
if (!adi_available ())
error (_("No ADI information"));
pid_t pid = ptid_get_pid (inferior_ptid);
sparc64_adi_info *proc = get_adi_info_proc (pid);
int cnt = 1;
char *p = args;
if (p && *p == '/')
{
p++;
cnt = get_number (&p);
}
CORE_ADDR next_address = 0;
if (p != 0 && *p != 0)
next_address = parse_and_eval_address (p);
if (!cnt || !next_address)
error (_("Usage: adi examine|x[/count] <addr>"));
do_examine (next_address, cnt);
}
/* ADI assign version tag command.
Command syntax:
adi (assign|a)/count <addr> = <version> */
static void
adi_assign_command (char *args, int from_tty)
{
/* make sure program is active and adi is available */
if (!target_has_execution)
error (_("ADI command requires a live process/thread"));
if (!adi_available ())
error (_("No ADI information"));
char *exp = args;
if (exp == 0)
error_no_arg (_("Usage: adi assign|a[/count] <addr> = <version>"));
char *q = (char *) strchr (exp, '=');
if (q)
*q++ = 0;
else
error (_("Usage: adi assign|a[/count] <addr> = <version>"));
size_t cnt = 1;
char *p = args;
if (exp && *exp == '/')
{
p = exp + 1;
cnt = get_number (&p);
}
CORE_ADDR next_address = 0;
if (p != 0 && *p != 0)
next_address = parse_and_eval_address (p);
else
error (_("Usage: adi assign|a[/count] <addr> = <version>"));
int version = 0;
if (q != NULL) /* parse version tag */
{
adi_stat_t ast = get_adi_info (ptid_get_pid (inferior_ptid));
version = parse_and_eval_long (q);
if (version < 0 || version > ast.max_version)
error (_("Invalid ADI version tag %d"), version);
}
do_assign (next_address, cnt, version);
}
void
_initialize_sparc64_adi_tdep (void)
{
add_prefix_cmd ("adi", class_support, info_adi_command,
_("ADI version related commands."),
&sparc64adilist, "adi ", 0, &cmdlist);
add_cmd ("examine", class_support, adi_examine_command,
_("Examine ADI versions."), &sparc64adilist);
add_alias_cmd ("x", "examine", no_class, 1, &sparc64adilist);
add_cmd ("assign", class_support, adi_assign_command,
_("Assign ADI versions."), &sparc64adilist);
}
/* The functions on this page are intended to be used to classify
function arguments. */
@ -1290,6 +1789,14 @@ sparc64_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
}
}
/* sparc64_addr_bits_remove - remove useless address bits */
static CORE_ADDR
sparc64_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR addr)
{
return adi_normalize_address (addr);
}
void
sparc64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
@ -1342,6 +1849,8 @@ sparc64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
frame_unwind_append_unwinder (gdbarch, &sparc64_frame_unwind);
frame_base_set_default (gdbarch, &sparc64_frame_base);
set_gdbarch_addr_bits_remove (gdbarch, sparc64_addr_bits_remove);
}