diff options
| author | Lai Jiangshan <jiangshan.ljs@antgroup.com> | 2022-04-21 22:10:48 +0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-05-03 11:18:59 +0200 |
| commit | 0aca53c6b522f8d6e2681ca875acbbe105f5fdcf (patch) | |
| tree | 4ccbb959b3336d3b7d84f385e290175c6c32b4f2 /arch/x86/kernel/traps.c | |
| parent | 672c0c5173427e6b3e2a9bbb7be51ceeec78093a (diff) | |
x86/traps: Use pt_regs directly in fixup_bad_iret()
Always stash the address error_entry() is going to return to, in %r12
and get rid of the void *error_entry_ret; slot in struct bad_iret_stack
which was supposed to account for it and pt_regs pushed on the stack.
After this, both fixup_bad_iret() and sync_regs() can work on a struct
pt_regs pointer directly.
[ bp: Rewrite commit message, touch ups. ]
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220503032107.680190-2-jiangshanlai@gmail.com
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 1563fb995005..4167215333fd 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -892,14 +892,10 @@ sync: } #endif -struct bad_iret_stack { - void *error_entry_ret; - struct pt_regs regs; -}; - -asmlinkage __visible noinstr -struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) +asmlinkage __visible noinstr struct pt_regs *fixup_bad_iret(struct pt_regs *bad_regs) { + struct pt_regs tmp, *new_stack; + /* * This is called from entry_64.S early in handling a fault * caused by a bad iret to user mode. To handle the fault @@ -908,19 +904,18 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) * just below the IRET frame) and we want to pretend that the * exception came from the IRET target. */ - struct bad_iret_stack tmp, *new_stack = - (struct bad_iret_stack *)__this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1; + new_stack = (struct pt_regs *)__this_cpu_read(cpu_tss_rw.x86_tss.sp0) - 1; /* Copy the IRET target to the temporary storage. */ - __memcpy(&tmp.regs.ip, (void *)s->regs.sp, 5*8); + __memcpy(&tmp.ip, (void *)bad_regs->sp, 5*8); /* Copy the remainder of the stack from the current stack. */ - __memcpy(&tmp, s, offsetof(struct bad_iret_stack, regs.ip)); + __memcpy(&tmp, bad_regs, offsetof(struct pt_regs, ip)); /* Update the entry stack */ __memcpy(new_stack, &tmp, sizeof(tmp)); - BUG_ON(!user_mode(&new_stack->regs)); + BUG_ON(!user_mode(new_stack)); return new_stack; } #endif |