On 9/10/2021 2:22 AM, Heiner Kallweit wrote: > In certain cases we need a variant of pci_read_vpd()/pci_write_vpd() that > does not check against dev->vpd.len. Such cases are: > - reading VPD if dev->vpd.len isn't set yet (in pci_vpd_size()) > - devices that map non-VPD information to arbitrary places in VPD address > space (example: Chelsio T3 EEPROM write-protect flag) > Therefore add function variants that check against PCI_VPD_MAX_SIZE only. > > Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx Reverting this series fixed a hang or stack overflow while reading things like, /sys/devices/pci0000:00/0000:00:00.0/0000:01:00.0/vpd [ 125.797082] Insufficient stack space to handle exception! [ 125.797091] ESR: 0x96000047 -- DABT (current EL) [ 125.797095] FAR: 0xffff80002433ffc0 [ 125.797096] Task stack: [0xffff800024340000..0xffff800024350000] [ 125.797099] IRQ stack: [0xffff8000101c0000..0xffff8000101d0000] [ 125.797102] Overflow stack: [0xffff009b675b02b0..0xffff009b675b12b0] [ 125.797106] CPU: 14 PID: 1550 Comm: lsbug Not tainted 5.15.0-rc5-next-20211012 #143 [ 125.797110] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.6 06/28/2020 [ 125.797114] pstate: 10000005 (nzcV daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 125.797118] pc : pci_vpd_size+0xc/0x1f8 [ 125.797128] lr : pci_vpd_read+0x2ec/0x420 [ 125.797132] sp : ffff800024340060 [ 125.797133] x29: ffff800024340060 x28: ffff00001a54cbcc x27: 0000000000000000 [ 125.797142] x26: ffff800024340210 x25: 0000000000000004 x24: 1fffe000034a9979 [ 125.797148] x23: ffff00001a54cbc8 x22: ffff00001a54cb38 x21: 0000000000008000 [ 125.797153] x20: 1fffe000034a9979 x19: ffff00001a54c000 x18: 0000000000000000 [ 125.797158] x17: 0000000000000000 x16: 0000000000000000 x15: dfff800000000000 [ 125.797163] x14: ffff800019ab0560 x13: 1fffe00110f9272f x12: ffff60010e945be1 [ 125.797168] x11: 1fffe0010e945be0 x10: 1ffff00004868022 x9 : ffff800010d1a38c [ 125.797174] x8 : ffff700004868022 x7 : dfff800000000000 x6 : 0000000000000000 [ 125.797179] x5 : ffff000887c93540 x4 : 0000000000000000 x3 : ffff800024340210 [ 125.797184] x2 : 0000000000000001 x1 : 0000000000000003 x0 : ffff00001a54c000 [ 125.797190] Kernel panic - not syncing: kernel stack overflow [ 125.797193] CPU: 14 PID: 1550 Comm: lsbug Not tainted 5.15.0-rc5-next-20211012 #143 [ 125.797197] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.6 06/28/2020 [ 125.797199] Call trace: [ 125.797201] dump_backtrace+0x0/0x3b8 [ 125.797208] show_stack+0x20/0x30 [ 125.797212] dump_stack_lvl+0x8c/0xb8 [ 125.797216] dump_stack+0x1c/0x38 [ 125.797219] panic+0x2b0/0x538 [ 125.797224] add_taint+0x0/0xe8 [ 125.797229] panic_bad_stack+0x1e4/0x230 [ 125.797233] handle_bad_stack+0x38/0x50 [ 125.797237] __bad_stack+0x88/0x8c [ 125.797241] pci_vpd_size+0xc/0x1f8 [ 125.797244] __pci_read_vpd+0x114/0x158 [ 125.797247] pci_vpd_size+0xa0/0x1f8 [ 125.797251] pci_vpd_read+0x2ec/0x420 [ 125.797254] __pci_read_vpd+0x114/0x158 [ 125.797258] pci_vpd_size+0xa0/0x1f8 [ 125.797261] pci_vpd_read+0x2ec/0x420 ... [ 125.798534] __pci_read_vpd+0x114/0x158 [ 125.798538] pci_vpd_size+0xa0/0x1f8 [ 125.798541] pci_vpd_read+0x2ec/0x420 [ 125.798545] __pci_read_vpd+0x114/0x158 __pci_read_vpd at /usr/src/linux-next/drivers/pci/vpd.c:398 [ 125.798548] vpd_read+0x28/0x38 vpd_read at /usr/src/linux-next/drivers/pci/vpd.c:276 [ 125.798551] sysfs_kf_bin_read+0x120/0x218 [ 125.798556] kernfs_fop_read_iter+0x244/0x4a8 [ 125.798559] new_sync_read+0x2bc/0x4e8 [ 125.798564] vfs_read+0x18c/0x390 [ 125.798567] ksys_read+0xf8/0x1e0 [ 125.798570] __arm64_sys_read+0x74/0xa8 [ 125.798574] invoke_syscall.constprop.0+0xdc/0x1d8 [ 125.798578] do_el0_svc+0xe4/0x298 [ 125.798582] el0_svc+0x64/0x130 [ 125.798586] el0t_64_sync_handler+0xb0/0xb8 [ 125.798590] el0t_64_sync+0x180/0x184 [ 125.798598] ------------[ cut here ]------------ [ 125.798600] WARNING: CPU: -32 PID: 1550 at include/linux/cpumask.h:108 smp_send_stop+0x4a4/0x5e8 [ 125.798607] Modules linked in: loop cppc_cpufreq efivarfs ip_tables x_tables ext4 mbcache jbd2 dm_mod igb i2c_algo_bit nvme mlx5_core i2c_core nvme_core firmware_class [ 125.798632] CPU: 791961908 PID: 1550 Comm: lsbug Not tainted 5.15.0-rc5-next-20211012 #143 [ 125.798637] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.6 06/28/2020 [ 125.798639] pstate: a00003c5 (NzCv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 125.798643] pc : smp_send_stop+0x4a4/0x5e8 [ 125.798647] lr : panic+0x2b8/0x538 [ 125.798650] sp : ffff009b675b0c70 [ 125.798652] x29: ffff009b675b0c70 x28: ffff000887c92ec0 x27: 0000000000000000 [ 125.798658] x26: 0000000000000025 x25: ffff809b55bf0000 x24: ffff800011eeb4d0 [ 125.798663] x23: ffff800011426680 x22: ffff800019393000 x21: ffff800019dfa000 [ 125.798668] x20: 00000000ffffffe0 x19: ffff8000119c0000 x18: 0000000000000000 [ 125.798673] x17: 0000000000000000 x16: 0000000000000002 x15: 0000000000000000 [ 125.798678] x14: 0000000000000000 x13: 000000000000000f x12: ffff7000023ef669 [ 125.798683] x11: 1ffff000023ef668 x10: ffff7000023ef668 x9 : ffff80001133f2cc [ 125.798688] x8 : 0000000000000003 x7 : 0000000000000001 x6 : ffff800011f7b340 [ 125.798693] x5 : 1fffe0136ceb619e x4 : 0000000041b58ab3 x3 : 1fffe0136ceb6000 [ 125.798698] x2 : 1ffff000023dd69a x1 : 0000000000000000 x0 : 0000000000000020 [ 125.798704] Call trace: [ 125.798705] smp_send_stop+0x4a4/0x5e8 [ 125.798709] panic+0x2b8/0x538 [ 125.798713] add_taint+0x0/0xe8 [ 125.798717] panic_bad_stack+0x1e4/0x230 [ 125.798720] handle_bad_stack+0x38/0x50 [ 125.798724] __bad_stack+0x88/0x8c [ 125.798727] pci_vpd_size+0xc/0x1f8 [ 125.798731] __pci_read_vpd+0x114/0x158 [ 125.798734] pci_vpd_size+0xa0/0x1f8 [ 125.798738] pci_vpd_read+0x2ec/0x420 [ 125.798741] __pci_read_vpd+0x114/0x158 [ 125.798744] pci_vpd_size+0xa0/0x1f8 [ 125.798748] pci_vpd_read+0x2ec/0x420
