[XTENSA] Allow debugger to modify the WINDOWBASE register.

For the 'return' command, GDB needs to adjust WINDOWBASE.
In case WB is different from 0, we need to rotate the
window register file and update WINDOWSTART and WMASK.
This patch also removes some ret|= statements for
__get_user/__put_user as the address range was alrady
checked a couple of lines earlier.

Signed-off-by: Chris Zankel <chris@zankel.net>
This commit is contained in:
Chris Zankel 2008-01-28 15:55:01 -08:00
parent bdd362ff4f
commit 42086cec32
2 changed files with 37 additions and 32 deletions

View File

@ -43,32 +43,29 @@ int ptrace_getregs(struct task_struct *child, void __user *uregs)
{ {
struct pt_regs *regs = task_pt_regs(child); struct pt_regs *regs = task_pt_regs(child);
xtensa_gregset_t __user *gregset = uregs; xtensa_gregset_t __user *gregset = uregs;
unsigned long wb = regs->windowbase;
unsigned long ws = regs->windowstart;
unsigned long wm = regs->wmask; unsigned long wm = regs->wmask;
int ret = 0; unsigned long wb = regs->windowbase;
int live, last; int live, i;
if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
return -EIO; return -EIO;
/* Norm windowstart to a windowbase of 0. */ __put_user(regs->pc, &gregset->pc);
__put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
ws = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1); __put_user(regs->lbeg, &gregset->lbeg);
__put_user(regs->lend, &gregset->lend);
ret |= __put_user(regs->pc, &gregset->pc); __put_user(regs->lcount, &gregset->lcount);
ret |= __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps); __put_user(regs->windowstart, &gregset->windowstart);
ret |= __put_user(regs->lbeg, &gregset->lbeg); __put_user(regs->windowbase, &gregset->windowbase);
ret |= __put_user(regs->lend, &gregset->lend);
ret |= __put_user(regs->lcount, &gregset->lcount);
ret |= __put_user(ws, &gregset->windowstart);
live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
last = XCHAL_NUM_AREGS - (wm >> 4) * 4;
ret |= __copy_to_user(gregset->a, regs->areg, live * 4);
ret |= __copy_to_user(gregset->a + last, regs->areg + last, (wm>>4)*16);
return ret ? -EFAULT : 0; for (i = 0; i < live; i++)
__put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++)
__put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
return 0;
} }
int ptrace_setregs(struct task_struct *child, void __user *uregs) int ptrace_setregs(struct task_struct *child, void __user *uregs)
@ -76,28 +73,35 @@ int ptrace_setregs(struct task_struct *child, void __user *uregs)
struct pt_regs *regs = task_pt_regs(child); struct pt_regs *regs = task_pt_regs(child);
xtensa_gregset_t *gregset = uregs; xtensa_gregset_t *gregset = uregs;
const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK; const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
unsigned long wm = regs->wmask;
unsigned long ps; unsigned long ps;
int ret = 0; unsigned long wb;
int live, last;
if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t))) if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
return -EIO; return -EIO;
ret |= __get_user(regs->pc, &gregset->pc); __get_user(regs->pc, &gregset->pc);
ret |= __get_user(ps, &gregset->ps); __get_user(ps, &gregset->ps);
ret |= __get_user(regs->lbeg, &gregset->lbeg); __get_user(regs->lbeg, &gregset->lbeg);
ret |= __get_user(regs->lend, &gregset->lend); __get_user(regs->lend, &gregset->lend);
ret |= __get_user(regs->lcount, &gregset->lcount); __get_user(regs->lcount, &gregset->lcount);
__get_user(regs->windowstart, &gregset->windowstart);
__get_user(wb, &gregset->windowbase);
regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT); regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16; if (wb >= XCHAL_NUM_AREGS / 4)
last = XCHAL_NUM_AREGS - (wm >> 4) * 4; return -EFAULT;
ret |= __copy_from_user(regs->areg, gregset->a, live * 4);
ret |= __copy_from_user(regs->areg+last, gregset->a+last, (wm>>4)*16);
return ret ? -EFAULT : 0; regs->windowbase = wb;
if (wb != 0 && __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
gregset->a, wb * 16))
return -EFAULT;
if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16))
return -EFAULT;
return 0;
} }

View File

@ -82,7 +82,8 @@ typedef struct {
elf_greg_t lcount; elf_greg_t lcount;
elf_greg_t sar; elf_greg_t sar;
elf_greg_t windowstart; elf_greg_t windowstart;
elf_greg_t reserved[9+48]; elf_greg_t windowbase;
elf_greg_t reserved[8+48];
elf_greg_t a[64]; elf_greg_t a[64];
} xtensa_gregset_t; } xtensa_gregset_t;