The breakpoint code mixes up attribute check and commit into a single code entity. Therefore the validation may return an error due to incorrect atributes while still leaving halfway modified architecture breakpoint struct.
Prepare fox fixing this misdesign and separate both logics. Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Yoshinori Sato <[email protected]> Cc: Rich Felker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Max Filippov <[email protected]> Cc: Chris Zankel <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> --- arch/xtensa/kernel/hw_breakpoint.c | 60 ++++++++++++++++++++++++++------------ 1 file changed, 42 insertions(+), 18 deletions(-) diff --git a/arch/xtensa/kernel/hw_breakpoint.c b/arch/xtensa/kernel/hw_breakpoint.c index b35656a..aae055d 100644 --- a/arch/xtensa/kernel/hw_breakpoint.c +++ b/arch/xtensa/kernel/hw_breakpoint.c @@ -45,15 +45,38 @@ int arch_check_bp_in_kernelspace(struct perf_event *bp) return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE); } -/* - * Construct an arch_hw_breakpoint from a perf_event. - */ -static int arch_build_bp_info(struct perf_event *bp) +static int hw_breakpoint_arch_check(struct perf_event *bp, + const struct perf_event_attr *attr) +{ + /* Type */ + switch (attr->bp_type) { + case HW_BREAKPOINT_X: + case HW_BREAKPOINT_R: + case HW_BREAKPOINT_W: + case HW_BREAKPOINT_RW: + break; + default: + return -EINVAL; + } + + /* Len */ + if (attr->bp_len < 1 || attr->bp_len > 64 || !is_power_of_2(attr->bp_len)) + return -EINVAL; + + /* Address */ + if (attr->bp_addr & (attr->bp_len - 1)) + return -EINVAL; + + return 0; +} + +static void hw_breakpoint_arch_commit(struct perf_event *bp) { struct arch_hw_breakpoint *info = counter_arch_bp(bp); + struct perf_event_attr *attr = &bp->attr; /* Type */ - switch (bp->attr.bp_type) { + switch (attr->bp_type) { case HW_BREAKPOINT_X: info->type = XTENSA_BREAKPOINT_EXECUTE; break; @@ -67,29 +90,30 @@ static int arch_build_bp_info(struct perf_event *bp) info->type = XTENSA_BREAKPOINT_LOAD | XTENSA_BREAKPOINT_STORE; break; default: - return -EINVAL; + WARN_ON_ONCE(1); } /* Len */ - info->len = bp->attr.bp_len; - if (info->len < 1 || info->len > 64 || !is_power_of_2(info->len)) - return -EINVAL; + info->len = attr->bp_len; /* Address */ - info->address = bp->attr.bp_addr; - if (info->address & (info->len - 1)) - return -EINVAL; - - return 0; + info->address = attr->bp_addr; } +/* + * Validate the arch-specific HW Breakpoint register settings + */ int arch_validate_hwbkpt_settings(struct perf_event *bp) { - int ret; + int err; - /* Build the arch_hw_breakpoint. */ - ret = arch_build_bp_info(bp); - return ret; + err = hw_breakpoint_arch_check(bp, &bp->attr); + if (err) + return err; + + hw_breakpoint_arch_commit(bp); + + return 0; } int hw_breakpoint_exceptions_notify(struct notifier_block *unused, -- 2.7.4
