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/powerpc/kernel/hw_breakpoint.c | 82 ++++++++++++++++++++++++------------- 1 file changed, 53 insertions(+), 29 deletions(-) diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index 4c1012b..c39fc86 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -138,33 +138,20 @@ int arch_bp_generic_fields(int type, int *gen_bp_type) return 0; } -/* - * Validate the arch-specific HW Breakpoint register settings - */ -int arch_validate_hwbkpt_settings(struct perf_event *bp) +static int hw_breakpoint_arch_check(struct perf_event *bp, + const struct perf_event_attr *attr) { - int ret = -EINVAL, length_max; - struct arch_hw_breakpoint *info = counter_arch_bp(bp); + int length_max; if (!bp) - return ret; + return -EINVAL; - info->type = HW_BRK_TYPE_TRANSLATE; - if (bp->attr.bp_type & HW_BREAKPOINT_R) - info->type |= HW_BRK_TYPE_READ; - if (bp->attr.bp_type & HW_BREAKPOINT_W) - info->type |= HW_BRK_TYPE_WRITE; - if (info->type == HW_BRK_TYPE_TRANSLATE) - /* must set alteast read or write */ - return ret; - if (!(bp->attr.exclude_user)) - info->type |= HW_BRK_TYPE_USER; - if (!(bp->attr.exclude_kernel)) - info->type |= HW_BRK_TYPE_KERNEL; - if (!(bp->attr.exclude_hv)) - info->type |= HW_BRK_TYPE_HYP; - info->address = bp->attr.bp_addr; - info->len = bp->attr.bp_len; + /* Must set at least read or write */ + if (!(attr->bp_type & (HW_BREAKPOINT_R | HW_BREAKPOINT_W))) + return -EINVAL; + + if (!ppc_breakpoint_available()) + return -ENODEV; /* * Since breakpoint length can be a maximum of HW_BREAKPOINT_LEN(8) @@ -172,19 +159,56 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) * HW_BREAKPOINT_ALIGN by rounding off to the lower address, the * 'symbolsize' should satisfy the check below. */ - if (!ppc_breakpoint_available()) - return -ENODEV; length_max = 8; /* DABR */ if (cpu_has_feature(CPU_FTR_DAWR)) { length_max = 512 ; /* 64 doublewords */ /* DAWR region can't cross 512 boundary */ - if ((bp->attr.bp_addr >> 10) != - ((bp->attr.bp_addr + bp->attr.bp_len - 1) >> 10)) + if ((attr->bp_addr >> 10) != + ((attr->bp_addr + attr->bp_len - 1) >> 10)) return -EINVAL; } - if (info->len > - (length_max - (info->address & HW_BREAKPOINT_ALIGN))) + if (attr->bp_len > + (length_max - (attr->bp_addr & HW_BREAKPOINT_ALIGN))) 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; + + info->type = HW_BRK_TYPE_TRANSLATE; + if (attr->bp_type & HW_BREAKPOINT_R) + info->type |= HW_BRK_TYPE_READ; + if (attr->bp_type & HW_BREAKPOINT_W) + info->type |= HW_BRK_TYPE_WRITE; + + if (!attr->exclude_user) + info->type |= HW_BRK_TYPE_USER; + if (!attr->exclude_kernel) + info->type |= HW_BRK_TYPE_KERNEL; + if (!attr->exclude_hv) + info->type |= HW_BRK_TYPE_HYP; + + info->address = attr->bp_addr; + info->len = attr->bp_len; +} + +/* + * Validate the arch-specific HW Breakpoint register settings + */ +int arch_validate_hwbkpt_settings(struct perf_event *bp) +{ + int err; + + err = hw_breakpoint_arch_check(bp, &bp->attr); + if (err) + return err; + + hw_breakpoint_arch_commit(bp); + return 0; } -- 2.7.4
