On 2/3/2024 3:52 PM, H. Peter Anvin wrote:
On January 31, 2024 1:14:52 PM PST, tip-bot2 for Xin Li <tip-bot2@xxxxxxxxxxxxx> wrote:The following commit has been merged into the x86/fred branch of tip: Commit-ID: ee63291aa8287cb7ded767d340155fe8681fc075 Gitweb: https://git.kernel.org/tip/ee63291aa8287cb7ded767d340155fe8681fc075 Author: Xin Li <xin3.li@xxxxxxxxx> AuthorDate: Tue, 05 Dec 2023 02:50:02 -08:00 Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx> CommitterDate: Wed, 31 Jan 2024 22:01:13 +01:00 x86/ptrace: Cleanup the definition of the pt_regs structure struct pt_regs is hard to read because the member or section related comments are not aligned with the members. The 'cs' and 'ss' members of pt_regs are type of 'unsigned long' while in reality they are only 16-bit wide. This works so far as the remaining space is unused, but FRED will use the remaining bits for other purposes. To prepare for FRED: - Cleanup the formatting - Convert 'cs' and 'ss' to u16 and embed them into an union with a u64 - Fixup the related printk() format strings Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Originally-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Signed-off-by: Xin Li <xin3.li@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Tested-by: Shan Kang <shan.kang@xxxxxxxxx> Link: https://lore.kernel.org/r/20231205105030.8698-14-xin3.li@xxxxxxxxx
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diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 33b2687..0f78b58 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -117,7 +117,7 @@ void __show_regs(struct pt_regs *regs, enum show_regs_mode mode, printk("%sFS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n", log_lvl, fs, fsindex, gs, gsindex, shadowgs); - printk("%sCS: %04lx DS: %04x ES: %04x CR0: %016lx\n", + printk("%sCS: %04x DS: %04x ES: %04x CR0: %016lx\n", log_lvl, regs->cs, ds, es, cr0); printk("%sCR2: %016lx CR3: %016lx CR4: %016lx\n", log_lvl, cr2, cr3, cr4);Incidentally, the comment about callee-saved registers is long since both obsolete and is now outright wrong. The next version of gcc (14 I think) will have an attribute to turn off saving registers which we can use for top-level C functions.
Forgive my ignorance, do we have an official definition for "top-level C functions"?
Thanks!
Xin
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