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* sparc64obsd-tdep.c: Tweak comments.

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(sparc64obsd_sigreturn_offset): Add offset for new OpenBSD 3.8
signal trampoline.
This commit is contained in:
Mark Kettenis 2005-08-09 19:32:59 +00:00
parent 2f168eed4b
commit 47b4f8300a
2 changed files with 24 additions and 10 deletions
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6
gdb/ChangeLog
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@ -1,3 +1,9 @@
2005-08-09 Mark Kettenis <kettenis@gnu.org>
* sparc64obsd-tdep.c: Tweak comments.
(sparc64obsd_sigreturn_offset): Add offset for new OpenBSD 3.8
signal trampoline.
2005-08-09 Andrew Cagney <cagney@gnu.org>
* linux-nat.h (linux_proc_xfer_memory): Change type of "myaddr" a

28
gdb/sparc64obsd-tdep.c
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@ -68,19 +68,27 @@ sparc64obsd_supply_gregset (const struct regset *regset,
/* Signal trampolines. */
/* The OpenBSD kernel maps the signal trampoline at some random
location in user space, which means that the traditional BSD way of
detecting it won't work.
/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
in virtual memory. The randomness makes it somewhat tricky to
detect it, but fortunately we can rely on the fact that the start
of the sigtramp routine is page-aligned. We recognize the
trampoline by looking for the code that invokes the sigreturn
system call. The offset where we can find that code varies from
release to release.
The signal trampoline will be mapped at an address that is page
aligned. We recognize the signal trampoline by the looking for the
sigreturn system call. The offset where we can find the code that
makes this system call varies from release to release. For OpenBSD
3.6 and later releases we can find the code at offset 0xec. For
OpenBSD 3.5 and earlier releases, we find it at offset 0xe8. */
By the way, the mapping mentioned above is read-only, so you cannot
place a breakpoint in the signal trampoline. */
/* Default page size. */
static const int sparc64obsd_page_size = 8192;
static const int sparc64obsd_sigreturn_offset[] = { 0xec, 0xe8, -1 };
/* Offset for sigreturn(2). */
static const int sparc64obsd_sigreturn_offset[] = {
0xf0, /* OpenBSD 3.8 */
0xec, /* OpenBSD 3.6 */
0xe8, /* OpenBSD 3.2 */
-1
};
static int
sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)