* frv-linux-tdep.c (frv_linux_sigcontext_reg_addr): Update comments.

Adjust incorrectly computed constant for realtime signal frame.
This commit is contained in:
Kevin Buettner 2005-03-18 20:23:28 +00:00
parent eb3088784c
commit f79d2c3cf8
2 changed files with 25 additions and 8 deletions

View File

@ -1,3 +1,8 @@
2005-03-18 Kevin Buettner <kevinb@redhat.com>
* frv-linux-tdep.c (frv_linux_sigcontext_reg_addr): Update comments.
Adjust incorrectly computed constant for realtime signal frame.
2005-03-18 Mark Kettenis <kettenis@elgar.sibelius.xs4all.nl>
From Ralf Corsepius <ralf.corsepius@rtems.org>

View File

@ -67,14 +67,14 @@ frv_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
return retval;
}
/* Given NEXT_FRAME, "callee" frame of the sigtramp frame that we
/* Given NEXT_FRAME, the "callee" frame of the sigtramp frame that we
wish to decode, and REGNO, one of the frv register numbers defined
in frv-tdep.h, return the address of the saved register (corresponding
to REGNO) in the sigtramp frame. Return -1 if the register is not
found in the sigtramp frame. The magic numbers in the code below
were computed by examining the following kernel structs:
From arch/frvnommu/signal.c:
From arch/frv/kernel/signal.c:
struct sigframe
{
@ -96,7 +96,7 @@ frv_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
uint32_t retcode[2];
};
From include/asm-frvnommu/ucontext.h:
From include/asm-frv/ucontext.h:
struct ucontext {
unsigned long uc_flags;
@ -106,14 +106,22 @@ frv_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
sigset_t uc_sigmask;
};
From include/asm-frvnommu/sigcontext.h:
From include/asm-frv/signal.h:
typedef struct sigaltstack {
void *ss_sp;
int ss_flags;
size_t ss_size;
} stack_t;
From include/asm-frv/sigcontext.h:
struct sigcontext {
struct user_context sc_context;
unsigned long sc_oldmask;
} __attribute__((aligned(8)));
From include/asm-frvnommu/registers.h:
From include/asm-frv/registers.h:
struct user_int_regs
{
unsigned long psr;
@ -184,15 +192,19 @@ frv_linux_sigcontext_reg_addr (struct frame_info *next_frame, int regno,
else if (tramp_type == RT_SIGTRAMP)
{
/* For a realtime sigtramp frame, SP + 12 contains a pointer
to the a ucontext struct. The ucontext struct contains
a sigcontext struct starting 12 bytes in. */
to the a ucontext struct. The ucontext struct contains a
sigcontext struct starting 24 bytes in. (The offset of
uc_mcontext within struct ucontext is derived as follows:
stack_t is a 12-byte struct and struct sigcontext is
8-byte aligned. This gives an offset of 8 + 12 + 4 (for
padding) = 24.) */
if (target_read_memory (sp + 12, buf, sizeof buf) != 0)
{
warning (_("Can't read realtime sigtramp frame."));
return 0;
}
sc_addr = extract_unsigned_integer (buf, sizeof buf);
sc_addr += 12;
sc_addr += 24;
}
else
internal_error (__FILE__, __LINE__, _("not a signal trampoline"));