On Wed, Mar 09, 2022 at 05:58:56PM +0100, Hans de Goede wrote: > Hi, > > On 3/9/22 17:52, Kees Cook wrote: > > On Wed, Mar 09, 2022 at 09:10:29PM +1100, Stephen Rothwell wrote: > >> Hi all, > >> > >> After merging the kspp tree, today's linux-next build (x86_64 > >> allmodconfig) failed like this: > >> > >> In file included from include/linux/bitops.h:33, > >> from include/linux/kernel.h:22, > >> from drivers/platform/x86/thinkpad_acpi.c:37: > >> drivers/platform/x86/thinkpad_acpi.c: In function 'tpacpi_dytc_profile_init': > >> arch/x86/include/asm/bitops.h:207:22: error: array subscript 'long unsigned int[0]' is partly outside array bounds of 'int[1]' [-Werror=array-bounds] > >> 207 | (addr[nr >> _BITOPS_LONG_SHIFT])) != 0; > >> | ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> drivers/platform/x86/thinkpad_acpi.c:10385:18: note: while referencing 'output' > >> 10385 | int err, output; > >> | ^~~~~~ > >> > >> Actually the test_bit() in line 10409. > >> > >> Caused by commit > >> > >> e1c21608e3cf ("platform/x86: thinkpad_acpi: Add PSC mode support") > >> > >> from the drivers-x86 tree interacting with the enablement of > >> -Werror=array-bounds. > >> > >> I have reverted that commit for today. > > Thank you. > > > Looking at https://lore.kernel.org/all/20220225182505.7234-1-markpearson@xxxxxxxxxx/ > > > > The problem is with the cast of "int output" to "unsigned long". Past > > fixes have either made the variable unsigned long, or adding a new > > variable and removal of casts. e.g. this pseudo-patch: > > > > + unsigned long bits; > > > > ... > > + bits = output; > > - if (test_bit(DYTC_FC_MMC, (void *)&output)) { /* MMC MODE */ > > + if (test_bit(DYTC_FC_MMC, &bits)) { /* MMC MODE */ > > > > ... > > > > - } else if (test_bit(DYTC_FC_PSC, (void *)&output)) { /*PSC MODE */ > > + } else if (test_bit(DYTC_FC_PSC, &bits)) { /*PSC MODE */ > > Right I was just preparing a patch for this, I've gone with: > > diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c > index 7016c7fc3440..c476a78599d6 100644 > --- a/drivers/platform/x86/thinkpad_acpi.c > +++ b/drivers/platform/x86/thinkpad_acpi.c > @@ -10399,7 +10399,7 @@ static int tpacpi_dytc_profile_init(struct ibm_init_struct *iibm) > if (err) > return err; > > - if (test_bit(DYTC_FC_MMC, (void *)&output)) { /* MMC MODE */ > + if (output & BIT(DYTC_FC_MMC)) { /* MMC MODE */ > dytc_profile_available = DYTC_FUNCMODE_MMC; > > /* > @@ -10412,7 +10412,7 @@ static int tpacpi_dytc_profile_init(struct ibm_init_struct *iibm) > if (!err && ((output & DYTC_ERR_MASK) == DYTC_ERR_SUCCESS)) > dytc_mmc_get_available = true; > } > - } else if (test_bit(DYTC_FC_PSC, (void *)&output)) { /*PSC MODE */ > + } else if (output & BIT(DYTC_FC_PSC)) { /* PSC MODE */ > dytc_profile_available = DYTC_FUNCMODE_PSC; > } else { > dbg_printk(TPACPI_DBG_INIT, "No DYTC support available\n"); > > I'll push this to the drivers-x86 tree for-next branch. Ah yeah. Heh, that's much simpler. :) -- Kees Cook