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authorVenki Pallipadi <venkatesh.pallipadi@intel.com>2008-09-08 10:18:40 -0700
committerIngo Molnar <mingo@elte.hu>2008-10-16 16:53:09 +0200
commitf0ed4e695faf6766927c8cfbda2bc7530c7210c2 (patch)
tree408d44ed257454030e0cb1628bf1365ec7d4a749
parent2a554fb132cf804477087057b9b0ff2162984507 (diff)
x86: using HPET in MSI mode and setting up per CPU HPET timers, fix
On Sat, Sep 06, 2008 at 06:03:53AM -0700, Ingo Molnar wrote: > > it crashes two testsystems, the fault on a NULL pointer in hpet init, > with: > > initcall print_all_ICs+0x0/0x520 returned 0 after 26 msecs > calling hpet_late_init+0x0/0x1c0 > BUG: unable to handle kernel NULL pointer dereference at 000000000000008c > IP: [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > PGD 0 > Oops: 0000 [1] SMP > CPU 0 > Modules linked in: > Pid: 1, comm: swapper Not tainted 2.6.27-rc5 #29725 > RIP: 0010:[<ffffffff80d228be>] [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP: 0018:ffff88003fa07dd0 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 > RDX: ffffc20000000160 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: ffff88003fa07e90 R08: 0000000000000000 R09: ffff88003fa07dd0 > R10: 0000000000000001 R11: 0000000000000000 R12: ffff88003fa07dd0 > R13: 0000000000000002 R14: ffffc20000000000 R15: 000000006f57e511 > FS: 0000000000000000(0000) GS:ffffffff80cf6a80(0000) knlGS:0000000000000000 > CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b > CR2: 000000000000008c CR3: 0000000000201000 CR4: 00000000000006e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Process swapper (pid: 1, threadinfo ffff88003fa06000, task ffff88003fa08000) > Stack: 00000000fed00000 ffffc20000000000 0000000100000003 0000000800000002 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > 0000000000000000 0000000000000000 0000000000000000 0000000000000000 > Call Trace: > [<ffffffff80d227c0>] ? hpet_late_init+0x0/0x1c0 > [<ffffffff80209045>] do_one_initcall+0x45/0x190 > [<ffffffff80296f39>] ? register_irq_proc+0x19/0xe0 > [<ffffffff80d0d140>] ? early_idt_handler+0x0/0x73 > [<ffffffff80d0dabc>] kernel_init+0x14c/0x1b0 > [<ffffffff80942ac1>] ? trace_hardirqs_on_thunk+0x3a/0x3f > [<ffffffff8020dbd9>] child_rip+0xa/0x11 > [<ffffffff8020ceee>] ? restore_args+0x0/0x30 > [<ffffffff80d0d970>] ? kernel_init+0x0/0x1b0 > [<ffffffff8020dbcf>] ? child_rip+0x0/0x11 > Code: 20 48 83 c1 01 48 39 f1 75 e3 44 89 e8 4c 8b 05 29 29 22 00 31 f6 48 8d 78 01 66 66 90 89 f0 48 8d 04 80 48 c1 e0 05 4a 8d 0c 00 <f6> 81 8c 00 00 00 08 74 26 8b 81 80 00 00 00 8b 91 88 00 00 00 > RIP [<ffffffff80d228be>] hpet_late_init+0xfe/0x1c0 > RSP <ffff88003fa07dd0> > CR2: 000000000000008c > Kernel panic - not syncing: Fatal exception There was one code path, with CONFIG_PCI_MSI disabled, where we were accessing hpet_devs without initialization. That resulted in the above crash. The change below adds a check for hpet_devs. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/hpet.c28
1 files changed, 19 insertions, 9 deletions
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 31e9191b7e1..01005aeda7d 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -126,6 +126,24 @@ EXPORT_SYMBOL_GPL(is_hpet_enabled);
* timer 0 and timer 1 in case of RTC emulation.
*/
#ifdef CONFIG_HPET
+static void hpet_reserve_msi_timers(struct hpet_data *hd)
+{
+ int i;
+
+ if (!hpet_devs)
+ return;
+
+ for (i = 0; i < hpet_num_timers; i++) {
+ struct hpet_dev *hdev = &hpet_devs[i];
+
+ if (!(hdev->flags & HPET_DEV_VALID))
+ continue;
+
+ hd->hd_irq[hdev->num] = hdev->irq;
+ hpet_reserve_timer(hd, hdev->num);
+ }
+}
+
static void hpet_reserve_platform_timers(unsigned long id)
{
struct hpet __iomem *hpet = hpet_virt_address;
@@ -158,15 +176,7 @@ static void hpet_reserve_platform_timers(unsigned long id)
Tn_INT_ROUTE_CNF_MASK) >> Tn_INT_ROUTE_CNF_SHIFT;
}
- for (i = 0; i < nrtimers; i++) {
- struct hpet_dev *hdev = &hpet_devs[i];
-
- if (!(hdev->flags & HPET_DEV_VALID))
- continue;
-
- hd.hd_irq[hdev->num] = hdev->irq;
- hpet_reserve_timer(&hd, hdev->num);
- }
+ hpet_reserve_msi_timers(&hd);
hpet_alloc(&hd);