Commit cd6ef7ee authored by Michael Neuling's avatar Michael Neuling Committed by Michael Ellerman

powerpc/ptrace: Fix enforcement of DAWR constraints

Back when we first introduced the DAWR, in commit 4ae7ebe9
("powerpc: Change hardware breakpoint to allow longer ranges"), we
screwed up the constraint making it a 1024 byte boundary rather than a
512. This makes the check overly permissive. Fortunately GDB is the
only real user and it always did they right thing, so we never
noticed.

This fixes the constraint to 512 bytes.

Fixes: 4ae7ebe9 ("powerpc: Change hardware breakpoint to allow longer ranges")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent c786cf76
...@@ -178,8 +178,8 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) ...@@ -178,8 +178,8 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
if (cpu_has_feature(CPU_FTR_DAWR)) { if (cpu_has_feature(CPU_FTR_DAWR)) {
length_max = 512 ; /* 64 doublewords */ length_max = 512 ; /* 64 doublewords */
/* DAWR region can't cross 512 boundary */ /* DAWR region can't cross 512 boundary */
if ((bp->attr.bp_addr >> 10) != if ((bp->attr.bp_addr >> 9) !=
((bp->attr.bp_addr + bp->attr.bp_len - 1) >> 10)) ((bp->attr.bp_addr + bp->attr.bp_len - 1) >> 9))
return -EINVAL; return -EINVAL;
} }
if (info->len > if (info->len >
......
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