2017-11-08 19:29:38

by Yonghong Song

[permalink] [raw]
Subject: [RESEND PATCH tip] x86/idt: Remove X86_TRAP_BP initialization in idt_setup_traps()

Commit b70543a0b2b6("x86/idt: Move regular trap init to tables")
moves regular trap init for each trap vector into a table based
initialization. It introduced the initialization for vector
X86_TRAP_BP which was not in the original change and it breaks
uprobe functionality for x86_32. A program with uprobe
instrumented can have segfault on x86_32 instead of normal finish.
Uprobe still works on x86_64 even with this commit.

This patch removes X86_TRAP_BP from the structure def_idts
which is used in idt_setup_traps(). It also removes a redundant
entry for X86_TRAP_NMI in def_idts. Tested on both x86_64 and x86_32,
uprobe works fine.

Fixes: b70543a0b2b6("x86/idt: Move regular trap init to tables")
Reported-and-tested-by: Yonghong Song <[email protected]>
Signed-off-by: Yonghong Song <[email protected]>
---
arch/x86/kernel/idt.c | 2 --
1 file changed, 2 deletions(-)

[RESEND with adding [email protected] as the recipient.]

diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 723fa97..d985cef 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -92,8 +92,6 @@ static const __initdata struct idt_data def_idts[] = {
INTG(X86_TRAP_DF, double_fault),
#endif
INTG(X86_TRAP_DB, debug),
- INTG(X86_TRAP_NMI, nmi),
- INTG(X86_TRAP_BP, int3),

#ifdef CONFIG_X86_MCE
INTG(X86_TRAP_MC, &machine_check),
--
2.9.5


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