projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| a709ecc8 GKH |
1 | From 2060c44576c79086ff24718878d7edaa7384a985 Mon Sep 17 00:00:00 2001 |
| 2 | From: Alexey Starikovskiy <astarikovskiy@suse.de> | |
| 3 | Date: Fri, 16 Apr 2010 15:36:40 -0400 | |
| 4 | Subject: ACPI: EC: Limit burst to 64 bits | |
| 5 | ||
| 6 | From: Alexey Starikovskiy <astarikovskiy@suse.de> | |
| 7 | ||
| 8 | commit 2060c44576c79086ff24718878d7edaa7384a985 upstream. | |
| 9 | ||
| 10 | access_bit_width field is u8 in ACPICA, thus 256 value written to it | |
| 11 | becomes 0, causing divide by zero later. | |
| 12 | ||
| 13 | Proper fix would be to remove access_bit_width at all, just because | |
| 14 | we already have access_byte_width, which is access_bit_width / 8. | |
| 15 | Limit access width to 64 bit for now. | |
| 16 | ||
| 17 | https://bugzilla.kernel.org/show_bug.cgi?id=15749 | |
| 18 | fixes regression caused by the fix for: | |
| 19 | https://bugzilla.kernel.org/show_bug.cgi?id=14667 | |
| 20 | ||
| 21 | Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de> | |
| 22 | Signed-off-by: Len Brown <len.brown@intel.com> | |
| 23 | Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> | |
| 24 | ||
| 25 | --- | |
| 26 | drivers/acpi/acpica/exprep.c | 17 +++++++++++------ | |
| 27 | 1 file changed, 11 insertions(+), 6 deletions(-) | |
| 28 | ||
| 29 | --- a/drivers/acpi/acpica/exprep.c | |
| 30 | +++ b/drivers/acpi/acpica/exprep.c | |
| 31 | @@ -471,13 +471,18 @@ acpi_status acpi_ex_prep_field_value(str | |
| 32 | /* allow full data read from EC address space */ | |
| 33 | if (obj_desc->field.region_obj->region.space_id == | |
| 34 | ACPI_ADR_SPACE_EC) { | |
| 35 | - if (obj_desc->common_field.bit_length > 8) | |
| 36 | - obj_desc->common_field.access_bit_width = | |
| 37 | - ACPI_ROUND_UP(obj_desc->common_field. | |
| 38 | - bit_length, 8); | |
| 39 | + if (obj_desc->common_field.bit_length > 8) { | |
| 40 | + unsigned width = | |
| 41 | + ACPI_ROUND_BITS_UP_TO_BYTES( | |
| 42 | + obj_desc->common_field.bit_length); | |
| 43 | + // access_bit_width is u8, don't overflow it | |
| 44 | + if (width > 8) | |
| 45 | + width = 8; | |
| 46 | obj_desc->common_field.access_byte_width = | |
| 47 | - ACPI_DIV_8(obj_desc->common_field. | |
| 48 | - access_bit_width); | |
| 49 | + width; | |
| 50 | + obj_desc->common_field.access_bit_width = | |
| 51 | + 8 * width; | |
| 52 | + } | |
| 53 | } | |
| 54 | ||
| 55 | ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, |