Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
Pre-existing issues: - [High] This problem wasn't introduced by this patch, but there is a memory leak of the ioremap virtual memory area on suspend/resume. - [High] This problem wasn't introduced by this patch, but an ignored initialization error on resume leads to a guaranteed NULL pointer dereference in the hardware TLB flush path. - [High] This problem wasn't introduced by this patch, but a missing break in a timeout loop causes a soft lockup if the hardware fails to complete a TLB flush. -- commit 809ee345f7a00dcaa6e844219a8b666a3f9ffadb Author: Juergen Gross <[email protected]> agp/nvidia: Stop using 32-bit MSR interfaces This commit replaces the deprecated 32-bit MSR interfaces rdmsr() and wrmsr() with their 64-bit equivalents in the NVIDIA AGP driver. This is part of a planned removal of the 32-bit variants. > diff --git a/drivers/char/agp/nvidia-agp.c b/drivers/char/agp/nvidia-agp.c > index 4787391bb6b4f..3e760bc00afaa 100644 > --- a/drivers/char/agp/nvidia-agp.c > +++ b/drivers/char/agp/nvidia-agp.c [ ... ] [Severity: High] This isn't a bug introduced by this patch, but I noticed a potential memory leak on suspend/resume. Does this code leak the vmap area leading to vmalloc space exhaustion after repeated suspend/resume cycles? drivers/char/agp/nvidia-agp.c:nvidia_configure() { ... /* map aperture */ apbase_phys = pci_resource_start(agp_bridge->dev, AGP_APERTURE_BAR); nvidia_private.aperture = (volatile u32 __iomem *) ioremap(apbase_phys, 33 * PAGE_SIZE); ... } Because the driver defines no suspend hook: drivers/char/agp/nvidia-agp.c: ... static DEFINE_SIMPLE_DEV_PM_OPS(agp_nvidia_pm_ops, NULL, agp_nvidia_resume); ... The previous ioremap allocation is never unmapped via iounmap() when the system suspends. [Severity: High] This is a pre-existing issue, but I spotted a potential NULL pointer dereference in the hardware TLB flush path. Could a failure in nvidia_configure() during resume lead to a kernel crash? drivers/char/agp/nvidia-agp.c:agp_nvidia_resume() { ... /* reconfigure AGP hardware again */ nvidia_configure(); return 0; } The return value of nvidia_configure() is ignored. If ioremap fails during resume, nvidia_configure() returns -ENOMEM and nvidia_private.aperture remains NULL. Later, when nvidia_tlbflush() is called, it unconditionally dereferences nvidia_private.aperture: drivers/char/agp/nvidia-agp.c:nvidia_tlbflush() { ... /* flush TLB entries */ for (i = 0; i < 32 + 1; i++) temp = readl(nvidia_private.aperture+(i * PAGE_SIZE / sizeof(u32))); ... } [Severity: High] This isn't a bug introduced by this patch, but the timeout loop in nvidia_tlbflush() appears to be missing a break statement. Can this cause a soft lockup if the hardware fails to complete a TLB flush? drivers/char/agp/nvidia-agp.c:nvidia_tlbflush() { ... end = jiffies + 3*HZ; do { pci_read_config_dword(nvidia_private.dev_1, NVIDIA_1_WBC, &wbc_reg); if (time_before_eq(end, jiffies)) { printk(KERN_ERR PFX "TLB flush took more than 3 seconds.\n"); } } while (wbc_reg & nvidia_private.wbc_mask); ... } If the hardware enters an unexpected state and the timeout expires, the code prints an error message but lacks a break statement to exit the loop, which could trap the kernel in an infinite loop. -- Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=21
