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| author | Oleg Nesterov <oleg@redhat.com> | 2014-04-24 18:52:37 +0200 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2014-04-30 19:10:38 +0200 |
| commit | 78d9af4cd375880a574327210eb9dab572618364 (patch) | |
| tree | 8b20ed5d22d82192f8c3aad520d4eff6843c1214 | |
| parent | 97aa5cddbe9e01521137f337624469374e3cbde5 (diff) | |
| download | op-kernel-dev-78d9af4cd375880a574327210eb9dab572618364.zip op-kernel-dev-78d9af4cd375880a574327210eb9dab572618364.tar.gz | |
uprobes/x86: Cleanup the usage of arch_uprobe->def.fixups, make it u8
handle_riprel_insn() assumes that nobody else could modify ->fixups
before. This is correct but fragile, change it to use "|=".
Also make ->fixups u8, we are going to add the new members into the
union. It is not clear why UPROBE_FIX_RIP_.X lived in the upper byte,
redefine them so that they can fit into u8.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/uprobes.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 14 |
2 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h index 72caff7..9ce25ce 100644 --- a/arch/x86/include/asm/uprobes.h +++ b/arch/x86/include/asm/uprobes.h @@ -53,7 +53,7 @@ struct arch_uprobe { #ifdef CONFIG_X86_64 long riprel_target; #endif - u16 fixups; + u8 fixups; } def; }; }; diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 7824ce2..a8e1d7e 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -33,16 +33,16 @@ /* Post-execution fixups. */ /* Adjust IP back to vicinity of actual insn */ -#define UPROBE_FIX_IP 0x1 +#define UPROBE_FIX_IP 0x01 /* Adjust the return address of a call insn */ -#define UPROBE_FIX_CALL 0x2 +#define UPROBE_FIX_CALL 0x02 /* Instruction will modify TF, don't change it */ -#define UPROBE_FIX_SETF 0x4 +#define UPROBE_FIX_SETF 0x04 -#define UPROBE_FIX_RIP_AX 0x8000 -#define UPROBE_FIX_RIP_CX 0x4000 +#define UPROBE_FIX_RIP_AX 0x08 +#define UPROBE_FIX_RIP_CX 0x10 #define UPROBE_TRAP_NR UINT_MAX @@ -307,12 +307,12 @@ handle_riprel_insn(struct arch_uprobe *auprobe, struct insn *insn) * is NOT the register operand, so we use %rcx (register * #1) for the scratch register. */ - auprobe->def.fixups = UPROBE_FIX_RIP_CX; + auprobe->def.fixups |= UPROBE_FIX_RIP_CX; /* Change modrm from 00 000 101 to 00 000 001. */ *cursor = 0x1; } else { /* Use %rax (register #0) for the scratch register. */ - auprobe->def.fixups = UPROBE_FIX_RIP_AX; + auprobe->def.fixups |= UPROBE_FIX_RIP_AX; /* Change modrm from 00 xxx 101 to 00 xxx 000 */ *cursor = (reg << 3); } |
